CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Infrared spectroscopy - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"186edfb4-717b-45d3-8f01-1b0d6a25a0a4","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Infrared_spectroscopy","wgTitle":"Infrared spectroscopy","wgCurRevisionId":1257824774,"wgRevisionId":1257824774,"wgArticleId":15412,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Articles with short description","Short description is different from Wikidata","All articles with unsourced statements","Articles with unsourced statements from February 2024","Articles with unsourced statements from October 2019","Commons category link from Wikidata","Webarchive template wayback links","Infrared spectroscopy"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Infrared_spectroscopy", "wgRelevantArticleId":15412,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":50000,"wgRelatedArticlesCompat":[],"wgCentralAuthMobileDomain":false,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q70906","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform", "platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","ext.math.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher" ,"ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.math.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.4"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/1200px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="927"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/800px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="618"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/640px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="495"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Infrared spectroscopy - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Infrared_spectroscopy"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Infrared_spectroscopy&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Infrared_spectroscopy"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Infrared_spectroscopy rootpage-Infrared_spectroscopy skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Infrared+spectroscopy" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Infrared+spectroscopy" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Infrared+spectroscopy" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Infrared+spectroscopy" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Uses_and_applications" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Uses_and_applications"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Uses and applications</span> </div> </a> <ul id="toc-Uses_and_applications-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Theory" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Theory"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Theory</span> </div> </a> <button aria-controls="toc-Theory-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Theory subsection</span> </button> <ul id="toc-Theory-sublist" class="vector-toc-list"> <li id="toc-Number_of_vibrational_modes" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Number_of_vibrational_modes"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Number of vibrational modes</span> </div> </a> <ul id="toc-Number_of_vibrational_modes-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Practical_IR_spectroscopy" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Practical_IR_spectroscopy"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Practical IR spectroscopy</span> </div> </a> <button aria-controls="toc-Practical_IR_spectroscopy-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Practical IR spectroscopy subsection</span> </button> <ul id="toc-Practical_IR_spectroscopy-sublist" class="vector-toc-list"> <li id="toc-Sample_preparation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Sample_preparation"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Sample preparation</span> </div> </a> <ul id="toc-Sample_preparation-sublist" class="vector-toc-list"> <li id="toc-Gas_samples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Gas_samples"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.1</span> <span>Gas samples</span> </div> </a> <ul id="toc-Gas_samples-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Liquid_samples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Liquid_samples"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.2</span> <span>Liquid samples</span> </div> </a> <ul id="toc-Liquid_samples-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Solid_samples" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Solid_samples"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1.3</span> <span>Solid samples</span> </div> </a> <ul id="toc-Solid_samples-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Comparing_to_a_reference" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Comparing_to_a_reference"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Comparing to a reference</span> </div> </a> <ul id="toc-Comparing_to_a_reference-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-FTIR" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#FTIR"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>FTIR</span> </div> </a> <ul id="toc-FTIR-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Infrared_microscopy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Infrared_microscopy"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>Infrared microscopy</span> </div> </a> <ul id="toc-Infrared_microscopy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Other_methods_in_molecular_vibrational_spectroscopy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Other_methods_in_molecular_vibrational_spectroscopy"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5</span> <span>Other methods in molecular vibrational spectroscopy</span> </div> </a> <ul id="toc-Other_methods_in_molecular_vibrational_spectroscopy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Computational_infrared_microscopy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Computational_infrared_microscopy"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.6</span> <span>Computational infrared microscopy</span> </div> </a> <ul id="toc-Computational_infrared_microscopy-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Absorption_bands" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Absorption_bands"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Absorption bands</span> </div> </a> <button aria-controls="toc-Absorption_bands-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Absorption bands subsection</span> </button> <ul id="toc-Absorption_bands-sublist" class="vector-toc-list"> <li id="toc-Regions" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Regions"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Regions</span> </div> </a> <ul id="toc-Regions-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Badger's_rule" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Badger's_rule"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>Badger's rule</span> </div> </a> <ul id="toc-Badger's_rule-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Isotope_effects" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Isotope_effects"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Isotope effects</span> </div> </a> <ul id="toc-Isotope_effects-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Two-dimensional_IR" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Two-dimensional_IR"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Two-dimensional IR</span> </div> </a> <ul id="toc-Two-dimensional_IR-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Infrared spectroscopy</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 40 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-40" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">40 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Infrarooispektroskopie" title="Infrarooispektroskopie – Afrikaans" lang="af" hreflang="af" data-title="Infrarooispektroskopie" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%85%D8%B7%D9%8A%D8%A7%D9%81%D9%8A%D8%A9_%D8%A7%D9%84%D8%A3%D8%B4%D8%B9%D8%A9_%D8%AA%D8%AD%D8%AA_%D8%A7%D9%84%D8%AD%D9%85%D8%B1%D8%A7%D8%A1" title="مطيافية الأشعة تحت الحمراء – Arabic" lang="ar" hreflang="ar" data-title="مطيافية الأشعة تحت الحمراء" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%98%D0%BD%D1%84%D1%80%D0%B0%D1%87%D0%B5%D1%80%D0%B2%D0%B5%D0%BD%D0%B0_%D1%81%D0%BF%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D1%81%D0%BA%D0%BE%D0%BF%D0%B8%D1%8F" title="Инфрачервена спектроскопия – Bulgarian" lang="bg" hreflang="bg" data-title="Инфрачервена спектроскопия" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Espectrosc%C3%B2pia_infraroja" title="Espectroscòpia infraroja – Catalan" lang="ca" hreflang="ca" data-title="Espectroscòpia infraroja" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Infra%C4%8Derven%C3%A1_spektroskopie" title="Infračervená spektroskopie – Czech" lang="cs" hreflang="cs" data-title="Infračervená spektroskopie" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Infrar%C3%B8d_spektroskopi" title="Infrarød spektroskopi – Danish" lang="da" hreflang="da" data-title="Infrarød spektroskopi" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Infrarotspektroskopie" title="Infrarotspektroskopie – German" lang="de" hreflang="de" data-title="Infrarotspektroskopie" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Infrapunaspektroskoopia" title="Infrapunaspektroskoopia – Estonian" lang="et" hreflang="et" data-title="Infrapunaspektroskoopia" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%A6%CE%B1%CF%83%CE%BC%CE%B1%CF%84%CE%BF%CF%83%CE%BA%CE%BF%CF%80%CE%AF%CE%B1_%CF%85%CF%80%CE%B5%CF%81%CF%8D%CE%B8%CF%81%CE%BF%CF%85" title="Φασματοσκοπία υπερύθρου – Greek" lang="el" hreflang="el" data-title="Φασματοσκοπία υπερύθρου" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Espectroscop%C3%ADa_infrarroja" title="Espectroscopía infrarroja – Spanish" lang="es" hreflang="es" data-title="Espectroscopía infrarroja" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Infragorrien_espektroskopia" title="Infragorrien espektroskopia – Basque" lang="eu" hreflang="eu" data-title="Infragorrien espektroskopia" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B7%DB%8C%D9%81%E2%80%8C%D8%B4%D9%86%D8%A7%D8%B3%DB%8C_%D9%81%D8%B1%D9%88%D8%B3%D8%B1%D8%AE" title="طیف‌شناسی فروسرخ – Persian" lang="fa" hreflang="fa" data-title="طیف‌شناسی فروسرخ" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Spectroscopie_infrarouge" title="Spectroscopie infrarouge – French" lang="fr" hreflang="fr" data-title="Spectroscopie infrarouge" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Speictreasc%C3%B3pacht_infridhearg" title="Speictreascópacht infridhearg – Irish" lang="ga" hreflang="ga" data-title="Speictreascópacht infridhearg" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%A0%81%EC%99%B8%EC%84%A0_%EB%B6%84%EA%B4%91%EB%B2%95" title="적외선 분광법 – Korean" lang="ko" hreflang="ko" data-title="적외선 분광법" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%B5%D5%B6%D5%A9%D5%A1%D5%AF%D5%A1%D6%80%D5%B4%D5%AB%D6%80_%D5%BD%D5%BA%D5%A5%D5%AF%D5%BF%D6%80%D5%B8%D5%BD%D5%AF%D5%B8%D5%BA%D5%AB%D5%A1" title="Ենթակարմիր սպեկտրոսկոպիա – Armenian" lang="hy" hreflang="hy" data-title="Ենթակարմիր սպեկտրոսկոպիա" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Spektroskopi_inframerah" title="Spektroskopi inframerah – Indonesian" lang="id" hreflang="id" data-title="Spektroskopi inframerah" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Spettroscopia_infrarossa" title="Spettroscopia infrarossa – Italian" lang="it" hreflang="it" data-title="Spettroscopia infrarossa" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Infrav%C3%B6r%C3%B6s_spektroszk%C3%B3pia" title="Infravörös spektroszkópia – Hungarian" lang="hu" hreflang="hu" data-title="Infravörös spektroszkópia" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%98%D0%BD%D1%84%D1%80%D0%B0%D1%86%D1%80%D0%B2%D0%B5%D0%BD%D0%B0_%D1%81%D0%BF%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D1%81%D0%BA%D0%BE%D0%BF%D0%B8%D1%98%D0%B0" title="Инфрацрвена спектроскопија – Macedonian" lang="mk" hreflang="mk" data-title="Инфрацрвена спектроскопија" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Spektroskopi_inframerah" title="Spektroskopi inframerah – Malay" lang="ms" hreflang="ms" data-title="Spektroskopi inframerah" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Infraroodspectroscopie" title="Infraroodspectroscopie – Dutch" lang="nl" hreflang="nl" data-title="Infraroodspectroscopie" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E8%B5%A4%E5%A4%96%E5%88%86%E5%85%89%E6%B3%95" title="赤外分光法 – Japanese" lang="ja" hreflang="ja" data-title="赤外分光法" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Infrar%C3%B8d_spektroskopi" title="Infrarød spektroskopi – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Infrarød spektroskopi" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Infraqizil_spektroskopiya" title="Infraqizil spektroskopiya – Uzbek" lang="uz" hreflang="uz" data-title="Infraqizil spektroskopiya" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Spektroskopia_w_podczerwieni" title="Spektroskopia w podczerwieni – Polish" lang="pl" hreflang="pl" data-title="Spektroskopia w podczerwieni" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Espectroscopia_de_infravermelho" title="Espectroscopia de infravermelho – Portuguese" lang="pt" hreflang="pt" data-title="Espectroscopia de infravermelho" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Spectroscopie_%C3%AEn_infraro%C8%99u" title="Spectroscopie în infraroșu – Romanian" lang="ro" hreflang="ro" data-title="Spectroscopie în infraroșu" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru badge-Q17437796 badge-featuredarticle mw-list-item" title="featured article badge"><a href="https://ru.wikipedia.org/wiki/%D0%98%D0%BD%D1%84%D1%80%D0%B0%D0%BA%D1%80%D0%B0%D1%81%D0%BD%D0%B0%D1%8F_%D1%81%D0%BF%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D1%81%D0%BA%D0%BE%D0%BF%D0%B8%D1%8F" title="Инфракрасная спектроскопия – Russian" lang="ru" hreflang="ru" data-title="Инфракрасная спектроскопия" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Infrared_spectroscopy" title="Infrared spectroscopy – Simple English" lang="en-simple" hreflang="en-simple" data-title="Infrared spectroscopy" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Infra%C4%8Derven%C3%A1_spektroskopia" title="Infračervená spektroskopia – Slovak" lang="sk" hreflang="sk" data-title="Infračervená spektroskopia" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Infrarde%C4%8Da_spektroskopija" title="Infrardeča spektroskopija – Slovenian" lang="sl" hreflang="sl" data-title="Infrardeča spektroskopija" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Infracrvena_spektroskopija" title="Infracrvena spektroskopija – Serbian" lang="sr" hreflang="sr" data-title="Infracrvena spektroskopija" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Infracrvena_spektroskopija" title="Infracrvena spektroskopija – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Infracrvena spektroskopija" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Infrapunaspektroskopia" title="Infrapunaspektroskopia – Finnish" lang="fi" hreflang="fi" data-title="Infrapunaspektroskopia" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/K%C4%B1z%C4%B1l%C3%B6tesi_spektroskopi" title="Kızılötesi spektroskopi – Turkish" lang="tr" hreflang="tr" data-title="Kızılötesi spektroskopi" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%86%D0%BD%D1%84%D1%80%D0%B0%D1%87%D0%B5%D1%80%D0%B2%D0%BE%D0%BD%D0%B0_%D1%81%D0%BF%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D1%81%D0%BA%D0%BE%D0%BF%D1%96%D1%8F" title="Інфрачервона спектроскопія – Ukrainian" lang="uk" hreflang="uk" data-title="Інфрачервона спектроскопія" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Ph%E1%BB%95_h%E1%BB%93ng_ngo%E1%BA%A1i" title="Phổ hồng ngoại – Vietnamese" lang="vi" hreflang="vi" data-title="Phổ hồng ngoại" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E7%B4%85%E5%A4%96%E5%85%89%E8%AD%9C%E5%AD%B8" title="紅外光譜學 – Cantonese" lang="yue" hreflang="yue" data-title="紅外光譜學" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E7%BA%A2%E5%A4%96%E5%85%89%E8%B0%B1%E5%AD%A6" title="红外光谱学 – Chinese" lang="zh" hreflang="zh" data-title="红外光谱学" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q70906#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Infrared_spectroscopy" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Infrared_spectroscopy" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Infrared_spectroscopy"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Infrared_spectroscopy"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Infrared_spectroscopy" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Infrared_spectroscopy" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&oldid=1257824774" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Infrared_spectroscopy&id=1257824774&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FInfrared_spectroscopy"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FInfrared_spectroscopy"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Infrared_spectroscopy&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Infrared_spectroscopy&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Infrared_spectroscopy" hreflang="en"><span>Wikimedia Commons</span></a></li><li class="wb-otherproject-link wb-otherproject-wikiquote mw-list-item"><a href="https://en.wikiquote.org/wiki/Infrared_spectroscopy" hreflang="en"><span>Wikiquote</span></a></li><li class="wb-otherproject-link wb-otherproject-wikiversity mw-list-item"><a href="https://en.wikiversity.org/wiki/Infrared_Spectroscopy" hreflang="en"><span>Wikiversity</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q70906" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For a table of IR spectroscopy data, see <a href="/wiki/Infrared_spectroscopy_correlation_table" title="Infrared spectroscopy correlation table">infrared spectroscopy correlation table</a>.</div> <div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Measurement of infrared radiation's interaction with matter</div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/220px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg" decoding="async" width="220" height="170" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/330px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/26/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg/440px-Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg 2x" data-file-width="3300" data-file-height="2550" /></a><figcaption>OVIRS instrument of the OSIRIS-REx probe is a visible and infrared spectrometer</figcaption></figure> <p><b>Infrared spectroscopy</b> (<b>IR spectroscopy</b> or <b>vibrational spectroscopy</b>) is the measurement of the interaction of <a href="/wiki/Infrared" title="Infrared">infrared</a> radiation with <a href="/wiki/Matter" title="Matter">matter</a> by <a href="/wiki/Absorption_spectroscopy" title="Absorption spectroscopy">absorption</a>, <a href="/wiki/Emission_spectrum" title="Emission spectrum">emission</a>, or <a href="/wiki/Reflection_(physics)" title="Reflection (physics)">reflection</a>. It is used to study and identify <a href="/wiki/Chemical_substance" title="Chemical substance">chemical substances</a> or <a href="/wiki/Functional_group" title="Functional group">functional groups</a> in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify and verify known and unknown samples. The method or technique of infrared spectroscopy is conducted with an instrument called an <b>infrared spectrometer</b> (or spectrophotometer) which produces an <b>infrared spectrum</b>. An IR spectrum can be visualized in a graph of infrared light <a href="/wiki/Absorbance" title="Absorbance">absorbance</a> (or <a href="/wiki/Transmittance" title="Transmittance">transmittance</a>) on the vertical axis vs. <a href="/wiki/Frequency" title="Frequency">frequency</a>, <a href="/wiki/Wavenumber" title="Wavenumber">wavenumber</a> or <a href="/wiki/Wavelength" title="Wavelength">wavelength</a> on the horizontal axis. Typical <a href="/wiki/Units_of_measurement" class="mw-redirect" title="Units of measurement">units</a> of wavenumber used in IR spectra are <a href="/wiki/Reciprocal_centimeters" class="mw-redirect" title="Reciprocal centimeters">reciprocal centimeters</a>, with the symbol cm<sup>−1</sup>. Units of IR wavelength are commonly given in <a href="/wiki/Micrometre" title="Micrometre">micrometers</a> (formerly called "microns"), symbol μm, which are related to the wavenumber in a <a href="/wiki/Multiplicative_inverse" title="Multiplicative inverse">reciprocal</a> way. A common laboratory instrument that uses this technique is a <a href="/wiki/Fourier_transform_infrared_spectroscopy" class="mw-redirect" title="Fourier transform infrared spectroscopy">Fourier transform infrared</a> (FTIR) <a href="/wiki/Spectrometer" title="Spectrometer">spectrometer</a>. Two-dimensional IR is also possible as discussed <a href="#Two-dimensional_IR">below</a>. </p><p>The infrared portion of the <a href="/wiki/Electromagnetic_spectrum" title="Electromagnetic spectrum">electromagnetic spectrum</a> is usually divided into three regions; the <a href="/wiki/Near-infrared_spectroscopy" title="Near-infrared spectroscopy">near-</a>, mid- and <a href="/wiki/Far_infrared" title="Far infrared">far-</a> infrared, named for their relation to the visible spectrum. The higher-energy near-IR, approximately 14,000–4,000 cm<sup>−1</sup> (0.7–2.5 μm wavelength) can excite <a href="/wiki/Overtone_band" title="Overtone band">overtone</a> or combination modes of <a href="/wiki/Molecular_vibration" title="Molecular vibration">molecular vibrations</a>. The mid-infrared, approximately 4,000–400 cm<sup>−1</sup> (2.5–25 μm) is generally used to study the fundamental vibrations and associated <a href="/wiki/Rotational%E2%80%93vibrational_spectroscopy" title="Rotational–vibrational spectroscopy">rotational–vibrational</a> structure. The far-infrared, approximately 400–10 cm<sup>−1</sup> (25–1,000 μm) has low energy and may be used for <a href="/wiki/Rotational_spectroscopy" title="Rotational spectroscopy">rotational spectroscopy</a> and low frequency vibrations. The region from 2–130 cm<sup>−1</sup>, bordering the <a href="/wiki/Microwave" title="Microwave">microwave</a> region, is considered the <a href="/wiki/Terahertz_radiation" title="Terahertz radiation">terahertz</a> region and may probe intermolecular vibrations.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The names and classifications of these subregions are conventions, and are only loosely based on the relative molecular or electromagnetic properties. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Uses_and_applications">Uses and applications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=1" title="Edit section: Uses and applications"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff/lossless-page1-220px-Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff.png" decoding="async" width="220" height="171" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff/lossless-page1-330px-Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff/lossless-page1-440px-Mary_Moffit_using_Infrared_spectrophotometer_2012_017_b1f6_79407z11s.tiff.png 2x" data-file-width="3918" data-file-height="3039" /></a><figcaption>Infrared spectrophotometer used to analyze the <a href="/wiki/DEET" title="DEET">diethyltoluamide</a> insect repellent, 1960</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Portable_Screening_Devices_(1435)_(8225044148).jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Portable_Screening_Devices_%281435%29_%288225044148%29.jpg/170px-Portable_Screening_Devices_%281435%29_%288225044148%29.jpg" decoding="async" width="170" height="256" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Portable_Screening_Devices_%281435%29_%288225044148%29.jpg/255px-Portable_Screening_Devices_%281435%29_%288225044148%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/66/Portable_Screening_Devices_%281435%29_%288225044148%29.jpg/340px-Portable_Screening_Devices_%281435%29_%288225044148%29.jpg 2x" data-file-width="1848" data-file-height="2784" /></a><figcaption>US <a href="/wiki/Food_and_Drug_Administration" title="Food and Drug Administration">Food and Drug Administration</a> scientist uses portable near infrared spectroscopy device to detect potentially illegal substances</figcaption></figure> <p>Infrared spectroscopy is a simple and reliable technique widely used in both organic and inorganic chemistry, in research and industry. It is used in quality control, dynamic measurement, and monitoring applications such as the long-term unattended measurement of CO<sub>2</sub> concentrations in greenhouses and growth chambers by infrared gas analyzers.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>It is also used in <a href="/wiki/Forensic_analysis" class="mw-redirect" title="Forensic analysis">forensic analysis</a> in both criminal and civil cases, for example in identifying <a href="/wiki/Polymer_degradation" title="Polymer degradation">polymer degradation</a>. It can be used in determining the <a href="/wiki/Blood_alcohol_content" title="Blood alcohol content">blood alcohol content</a> of a suspected drunk driver. </p><p>IR spectroscopy has been used in identification of <a href="/wiki/Pigments" class="mw-redirect" title="Pigments">pigments</a> in <a href="/wiki/Paintings" class="mw-redirect" title="Paintings">paintings</a><sup id="cite_ref-ColourLex_2-0" class="reference"><a href="#cite_note-ColourLex-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> and other art objects<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> such as <a href="/wiki/Illuminated_manuscripts" class="mw-redirect" title="Illuminated manuscripts">illuminated manuscripts</a>.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>Infrared spectroscopy is also useful in measuring the degree of polymerization in <a href="/wiki/Polymer" title="Polymer">polymer</a> manufacture. Changes in the character or quantity of a particular bond are assessed by measuring at a specific frequency over time. Instruments can routinely record many spectra per second in situ, providing insights into reaction mechanism (e.g., detection of intermediates) and reaction progress.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>Infrared spectroscopy is utilized in the field of semiconductor microelectronics:<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> for example, infrared spectroscopy can be applied to semiconductors like <a href="/wiki/Silicon" title="Silicon">silicon</a>, <a href="/wiki/Gallium_arsenide" title="Gallium arsenide">gallium arsenide</a>, <a href="/wiki/Gallium_nitride" title="Gallium nitride">gallium nitride</a>, <a href="/wiki/Zinc_selenide" title="Zinc selenide">zinc selenide</a>, amorphous silicon, <a href="/wiki/Silicon_nitride" title="Silicon nitride">silicon nitride</a>, etc. </p><p>Another important application of infrared spectroscopy is in the <a href="/wiki/Food_industry" title="Food industry">food industry</a> to measure the <a href="/wiki/Concentration" title="Concentration">concentration</a> of various compounds in different food products.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Infrared spectroscopy is also used in gas leak detection devices such as the DP-IR and EyeCGAs.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> These devices detect hydrocarbon gas leaks in the transportation of natural gas and crude oil. </p><p>Infrared spectroscopy is an important analysis method in the recycling process of household <a href="/wiki/Waste_plastics" class="mw-redirect" title="Waste plastics">waste plastics</a>, and a convenient stand-off method to sort plastic of different polymers (<a href="/wiki/Polyethylene_terephthalate" title="Polyethylene terephthalate">PET</a>, <a href="/wiki/HDPE" class="mw-redirect" title="HDPE">HDPE</a>, ...).<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p><p>Other developments include a miniature IR-spectrometer that's linked to a cloud based database and suitable for personal everyday use,<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> and NIR-spectroscopic chips<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> that can be embedded in smartphones and various gadgets. </p><p>In catalysis research it is a very useful tool to characterize the catalyst,<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> as well as to detect intermediates<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>Infrared spectroscopy coupled with machine learning and artificial intelligence also has potential for rapid, accurate and non-invasive sensing of bacteria.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> The complex chemical composition of bacteria, including nucleic acids, proteins, carbohydrates and fatty acids, results in high-dimensional datasets where the essential features are effectively hidden under the total spectrum. Extraction of the essential features therefore requires advanced statistical methods such as machine learning and deep-neural networks. The potential of this technique for bacteria classification have been demonstrated for differentiation at the genus,<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> species<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> and serotype<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> taxonomic levels, and it has also been shown promising for antimicrobial susceptibility testing,<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> which is important for many clinical settings where faster susceptibility testing would decrease unnecessary blind-treatment with broad-spectrum antibiotics. The main limitation of this technique for clinical applications is the high sensitivity to technical equipment and sample preparation techniques, which makes it difficult to construct large-scale databases. Attempts in this direction have however been made by Bruker with the IR Biotyper for food microbiology.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Theory">Theory</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=2" title="Edit section: Theory"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Bromomethane_IR_spectroscopy.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Bromomethane_IR_spectroscopy.svg/280px-Bromomethane_IR_spectroscopy.svg.png" decoding="async" width="280" height="210" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Bromomethane_IR_spectroscopy.svg/420px-Bromomethane_IR_spectroscopy.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Bromomethane_IR_spectroscopy.svg/560px-Bromomethane_IR_spectroscopy.svg.png 2x" data-file-width="512" data-file-height="384" /></a><figcaption>Sample of an IR spec. reading; this one is from <a href="/wiki/Bromomethane" title="Bromomethane">bromomethane</a> (CH<sub>3</sub>Br), showing peaks around 3000, 1300, and 1000 cm<sup>−1</sup> (on the horizontal axis).</figcaption></figure> <p>Infrared spectroscopy exploits the fact that molecules absorb frequencies that are characteristic of their <a href="/wiki/Chemical_structure" title="Chemical structure">structure</a>. These absorptions occur at <a href="/wiki/Resonant_frequency" class="mw-redirect" title="Resonant frequency">resonant frequencies</a>, i.e. the frequency of the absorbed radiation matches the vibrational frequency. The energies are affected by the shape of the molecular <a href="/wiki/Potential_energy_surface" title="Potential energy surface">potential energy surfaces</a>, the masses of the atoms, and the associated <a href="/wiki/Vibronic_coupling" title="Vibronic coupling">vibronic coupling</a>.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Bromomethane.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Bromomethane.gif/260px-Bromomethane.gif" decoding="async" width="260" height="231" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/f/f5/Bromomethane.gif 1.5x" data-file-width="291" data-file-height="258" /></a><figcaption>3D animation of the symmetric stretch-compress mode of the C–H bonds of <a href="/wiki/Bromomethane" title="Bromomethane">bromomethane</a></figcaption></figure><p> In particular, in the <a href="/wiki/Born%E2%80%93Oppenheimer_approximation" title="Born–Oppenheimer approximation">Born–Oppenheimer</a> and harmonic approximations (i.e. when the <a href="/wiki/Molecular_Hamiltonian" title="Molecular Hamiltonian">molecular Hamiltonian</a> corresponding to the electronic <a href="/wiki/Ground_state" title="Ground state">ground state</a> can be approximated by a <a href="/wiki/Quantum_harmonic_oscillator" title="Quantum harmonic oscillator">harmonic oscillator</a> in the neighbourhood of the equilibrium <a href="/wiki/Molecular_geometry" title="Molecular geometry">molecular geometry</a>), the resonant frequencies are associated with the <a href="/wiki/Normal_modes" class="mw-redirect" title="Normal modes">normal modes</a> of vibration corresponding to the molecular electronic <a href="/wiki/Ground_state" title="Ground state">ground state</a> potential energy surface. Thus, it depends on both the nature of the bonds and the <a href="/wiki/Atomic_mass" title="Atomic mass">mass of the atoms</a> that are involved. Using the <a href="/wiki/Schr%C3%B6dinger_equation" title="Schrödinger equation">Schrödinger equation</a> leads to the selection rule for the <a href="/wiki/Molecular_vibration#Quantum_mechanics" title="Molecular vibration">vibrational quantum number</a> in the system undergoing vibrational changes: </p><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \bigtriangleup v=\pm 1}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>△</mo> <mi>v</mi> <mo>=</mo> <mo>±</mo> <mn>1</mn> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \bigtriangleup v=\pm 1}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/22c19ab01bbf73059294b2729d43103169973a53" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:9.908ex; height:2.176ex;" alt="{\displaystyle \bigtriangleup v=\pm 1}"></span> </p><p>The compression and extension of a bond may be likened to the behaviour of a <a href="/wiki/Spring_(device)" title="Spring (device)">spring</a>, but real molecules are hardly perfectly <a href="/wiki/Elastic_deformation" class="mw-redirect" title="Elastic deformation">elastic</a> in nature. If a bond between atoms is stretched, for instance, there comes a point at which the bond breaks and the molecule dissociates into atoms. Thus real molecules deviate from perfect harmonic motion and their molecular vibrational motion is <a href="/wiki/Anharmonicity" title="Anharmonicity">anharmonic</a>. An empirical expression that fits the energy curve of a diatomic molecule undergoing anharmonic extension and compression to a good approximation was derived by <a href="/wiki/Philip_M._Morse" title="Philip M. Morse">P.M. Morse</a>, and is called the <a href="/wiki/Morse_potential" title="Morse potential">Morse function</a>. Using the Schrödinger equation leads to the selection rule for the system undergoing vibrational changes : </p><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \bigtriangleup v=\pm 1,\pm 2,\pm 3,\cdot \cdot \cdot }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>△</mo> <mi>v</mi> <mo>=</mo> <mo>±</mo> <mn>1</mn> <mo>,</mo> <mo>±</mo> <mn>2</mn> <mo>,</mo> <mo>±</mo> <mn>3</mn> <mo>,</mo> <mo>⋅</mo> <mo>⋅</mo> <mo>⋅</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \bigtriangleup v=\pm 1,\pm 2,\pm 3,\cdot \cdot \cdot }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/dbad00fab19bd1a28172cd8afc647418af51a07a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:21.924ex; height:2.509ex;" alt="{\displaystyle \bigtriangleup v=\pm 1,\pm 2,\pm 3,\cdot \cdot \cdot }"></span><sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Number_of_vibrational_modes">Number of vibrational modes</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=3" title="Edit section: Number of vibrational modes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In order for a vibrational mode in a sample to be "IR active", it must be associated with changes in the molecular dipole moment. A permanent dipole is not necessary, as the rule requires only a <i>change</i> in dipole moment.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> </p><p>A molecule can vibrate in many ways, and each way is called a <b>vibrational mode</b>. For molecules with N number of atoms, geometrically <a href="/wiki/Linear_molecular_geometry" title="Linear molecular geometry">linear molecules</a> have 3<i>N</i> – 5 degrees of vibrational modes, whereas <a href="/wiki/Molecular_geometry" title="Molecular geometry">nonlinear molecules</a> have 3<i>N</i> – 6 degrees of vibrational modes (also called vibrational degrees of freedom). As examples linear <a href="/wiki/Carbon_dioxide" title="Carbon dioxide">carbon dioxide</a> (CO<sub>2</sub>) has 3 × 3 – 5 = 4, while non-linear <a href="/wiki/Water_(molecule)" class="mw-redirect" title="Water (molecule)">water (H<sub>2</sub>O)</a>, has only 3 × 3 – 6 = 3.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Co2_vibrations.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Co2_vibrations.svg/220px-Co2_vibrations.svg.png" decoding="async" width="220" height="79" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Co2_vibrations.svg/330px-Co2_vibrations.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/81/Co2_vibrations.svg/440px-Co2_vibrations.svg.png 2x" data-file-width="886" data-file-height="319" /></a><figcaption><a href="#Number_of_vibrational_modes">Stretching and bending oscillations</a> of the CO<sub>2</sub> carbon dioxide molecule. Upper left: symmetric stretching. Upper right: antisymmetric stretching. Lower line: degenerate pair of bending modes.</figcaption></figure> <p>Simple <a href="/wiki/Diatomic_molecule" title="Diatomic molecule">diatomic molecules</a> have only one bond and only one vibrational band. If the molecule is symmetrical, e.g. N<sub>2</sub>, the band is not observed in the IR spectrum, but only in the <a href="/wiki/Raman_spectrum" class="mw-redirect" title="Raman spectrum">Raman spectrum</a>. Asymmetrical diatomic molecules, e.g. carbon monoxide (<a href="/wiki/Carbon_monoxide" title="Carbon monoxide">CO</a>), absorb in the IR spectrum. More complex molecules have many bonds, and their vibrational spectra are correspondingly more complex, i.e. big molecules have many peaks in their IR spectra. </p><p>The atoms in a CH<sub>2</sub>X<sub>2</sub> group, commonly found in <a href="/wiki/Organic_compound" title="Organic compound">organic compounds</a> and where X can represent any other atom, can vibrate in nine different ways. Six of these vibrations involve only the <a href="/wiki/Methylene_group" title="Methylene group">CH<sub>2</sub></a> portion: two <b>stretching</b> modes (ν): <b>symmetric</b> (ν<sub>s</sub>) and <b>antisymmetric</b> (ν<sub>as</sub>); and four <b>bending</b> modes: <b>scissoring</b> (δ), <b>rocking</b> (ρ), <b>wagging</b> (ω) and <b>twisting</b> (τ), as shown below. Structures that do not have the two additional X groups attached have fewer modes because some modes are defined by specific relationships to those other attached groups. For example, in water, the rocking, wagging, and twisting modes do not exist because these types of motions of the H atoms represent simple rotation of the whole molecule rather than vibrations within it. In case of more complex molecules, <b>out-of-plane</b> (γ) vibrational modes can be also present.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> </p> <div style="clear:both;" class=""></div> <table class="wikitable"> <tbody><tr> <th style="background:#EAECF0;background:linear-gradient(to top right,#EAECF0 49%,#AAA 49.5%,#AAA 50.5%,#EAECF0 51%);line-height:1.2;padding:0.1em 0.4em;"><div style="margin-left:2em;text-align:right">Symmetry</div><div style="margin-right:2em;text-align:left"><br />Direction</div> </th> <th>Symmetric </th> <th>Antisymmetric </th></tr> <tr style="text-align: center;"> <th>Radial </th> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Symmetrical_stretching.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/0/0e/Symmetrical_stretching.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Symmetric stretching (ν<sub>s</sub>) </td> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Asymmetrical_stretching.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/0/0c/Asymmetrical_stretching.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Antisymmetric stretching (ν<sub>as</sub>) </td></tr> <tr style="text-align: center;"> <th>Latitudinal </th> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Scissoring.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/6/60/Scissoring.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Scissoring (δ) </td> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Modo_rotacao.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/1/14/Modo_rotacao.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Rocking (ρ) </td></tr> <tr style="text-align: center;"> <th>Longitudinal </th> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Wagging.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/8/84/Wagging.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Wagging (ω) </td> <td><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Twisting.gif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/4/40/Twisting.gif" decoding="async" width="210" height="150" class="mw-file-element" data-file-width="210" data-file-height="150" /></a></span><br />Twisting (τ) </td></tr></tbody></table> <p>These figures do not represent the "<a href="/wiki/Recoil" title="Recoil">recoil</a>" of the <a href="/wiki/Carbon" title="Carbon">C</a> atoms, which, though necessarily present to balance the overall movements of the molecule, are much smaller than the movements of the lighter <a href="/wiki/Hydrogen" title="Hydrogen">H</a> atoms. </p><p>The simplest and most important or <i>fundamental</i> IR bands arise from the excitations of normal modes, the simplest distortions of the molecule, from the <a href="/wiki/Ground_state" title="Ground state">ground state</a> with <a href="/wiki/Molecular_vibration#Quantum_mechanics" title="Molecular vibration">vibrational quantum number</a> <i>v</i> = 0 to the first <a href="/wiki/Excited_state" title="Excited state">excited state</a> with vibrational quantum number <i>v</i> = 1. In some cases, <a href="/wiki/Overtone_band" title="Overtone band">overtone bands</a> are observed. An overtone band arises from the absorption of a photon leading to a direct transition from the ground state to the second excited vibrational state (<i>v</i> = 2). Such a band appears at approximately twice the energy of the fundamental band for the same normal mode. Some excitations, so-called <i>combination modes</i>, involve simultaneous excitation of more than one normal mode. The phenomenon of <a href="/wiki/Fermi_resonance" title="Fermi resonance">Fermi resonance</a> can arise when two modes are similar in energy; Fermi resonance results in an unexpected shift in energy and intensity of the bands etc.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (October 2019)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="Practical_IR_spectroscopy">Practical IR spectroscopy</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=4" title="Edit section: Practical IR spectroscopy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The infrared spectrum of a sample is recorded by passing a beam of infrared light through the sample. When the frequency of the IR matches the vibrational frequency of a bond or collection of bonds, absorption occurs. Examination of the transmitted light reveals how much energy was absorbed at each frequency (or wavelength). This measurement can be achieved by scanning the wavelength range using a <a href="/wiki/Monochromator" title="Monochromator">monochromator</a>. Alternatively, the entire wavelength range is measured using a <a href="/wiki/Fourier_transform" title="Fourier transform">Fourier transform</a> instrument and then a <a href="/wiki/Transmittance" title="Transmittance">transmittance</a> or <a href="/wiki/Absorbance" title="Absorbance">absorbance</a> spectrum is extracted. </p><p>This technique is commonly used for analyzing samples with <a href="/wiki/Covalent_bond" title="Covalent bond">covalent bonds</a>. The number of bands roughly correlates with symmetry and molecular complexity. </p><p>A variety of devices are used to hold the sample in the path of the IR beam These devices are selected on the basis of their transparency in the region of interest and their resilience toward the sample. </p> <table class="wikitable"> <caption>Materials for containing IR samples<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <th>material</th> <th>transparency range (cm<sup>-1</sup>)</th> <th>comment </th></tr> <tr> <td><a href="/wiki/Sodium_chloride" title="Sodium chloride">Sodium chloride</a></td> <td>5000-650</td> <td>attacked (dissolved) by water, small alcohols, some amines </td></tr> <tr> <td><a href="/wiki/Calcium_fluoride" title="Calcium fluoride">Calcium fluoride</a></td> <td>4200-1300</td> <td>insoluble in most solvents </td></tr> <tr> <td><a href="/wiki/Silver_chloride" title="Silver chloride">Silver chloride</a></td> <td>5000-500</td> <td>attacked (dissolved) by amines, organosulfur compounds </td></tr></tbody></table> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:SolnIRcell.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a0/SolnIRcell.jpg/220px-SolnIRcell.jpg" decoding="async" width="220" height="223" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a0/SolnIRcell.jpg/330px-SolnIRcell.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a0/SolnIRcell.jpg/440px-SolnIRcell.jpg 2x" data-file-width="971" data-file-height="985" /></a><figcaption>Typical IR solution cell. The windows are <a href="/wiki/Calcium_fluoride" title="Calcium fluoride">CaF<sub>2</sub></a>.</figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="Sample_preparation">Sample preparation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=5" title="Edit section: Sample preparation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Gas_samples">Gas samples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=6" title="Edit section: Gas samples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Gaseous samples require a sample cell with a long <a href="/wiki/Optical_path_length" title="Optical path length">pathlength</a> to compensate for the diluteness. The pathlength of the sample cell depends on the concentration of the compound of interest. A simple glass tube with length of 5 to 10 cm equipped with infrared-transparent windows at both ends of the tube can be used for concentrations down to several hundred ppm. Sample gas concentrations well below ppm can be measured with a <a href="/wiki/White_cell_(spectroscopy)" class="mw-redirect" title="White cell (spectroscopy)">White's cell</a> in which the infrared light is guided with mirrors to travel through the gas. White's cells are available with optical pathlength starting from 0.5 m up to hundred meters.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading4"><h4 id="Liquid_samples">Liquid samples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=7" title="Edit section: Liquid samples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Liquid samples can be sandwiched between two plates of a salt (commonly <a href="/wiki/Sodium_chloride" title="Sodium chloride">sodium chloride</a>, or common salt, although a number of other salts such as <a href="/wiki/Potassium_bromide" title="Potassium bromide">potassium bromide</a> or <a href="/wiki/Calcium_fluoride" title="Calcium fluoride">calcium fluoride</a> are also used).<sup id="cite_ref-Har_30-0" class="reference"><a href="#cite_note-Har-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> The plates are transparent to the infrared light and do not introduce any lines onto the spectra. With increasing technology in computer filtering and manipulation of the results, samples in solution can now be measured accurately (water produces a broad absorbance across the range of interest, and thus renders the spectra unreadable without this computer treatment).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading4"><h4 id="Solid_samples">Solid samples</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=8" title="Edit section: Solid samples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Solid samples can be prepared in a variety of ways. One common method is to crush the sample with an oily <a href="/wiki/Mulling_agent" class="mw-redirect" title="Mulling agent">mulling agent</a> (usually mineral oil <a href="/wiki/Nujol" title="Nujol">Nujol</a>). A thin film of the mull is applied onto salt plates and measured. The second method is to grind a quantity of the sample with a specially purified salt (usually <a href="/wiki/Potassium_bromide" title="Potassium bromide">potassium bromide</a>) finely (to remove scattering effects from large crystals). This powder mixture is then pressed in a mechanical <a href="/wiki/Machine_press" title="Machine press">press</a> to form a translucent pellet through which the beam of the spectrometer can pass.<sup id="cite_ref-Har_30-1" class="reference"><a href="#cite_note-Har-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> A third technique is the "cast film" technique, which is used mainly for polymeric materials. The sample is first dissolved in a suitable, non-<a href="/wiki/Hygroscopy" title="Hygroscopy">hygroscopic</a> solvent. A drop of this solution is deposited on the surface of a <a href="/wiki/Potassium_bromide" title="Potassium bromide">KBr</a> or <a href="/wiki/Sodium_chloride" title="Sodium chloride">NaCl</a> cell. The solution is then evaporated to dryness and the film formed on the cell is analysed directly. Care is important to ensure that the film is not too thick otherwise light cannot pass through. This technique is suitable for qualitative analysis. The final method is to use <a href="/wiki/Microtomy" class="mw-redirect" title="Microtomy">microtomy</a> to cut a thin (20–100 μm) film from a solid sample. This is one of the most important ways of analysing failed plastic products for example because the integrity of the solid is preserved.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>In <a href="/wiki/Photoacoustic_spectroscopy" title="Photoacoustic spectroscopy">photoacoustic spectroscopy</a> the need for sample treatment is minimal. The sample, liquid or solid, is placed into the sample cup which is inserted into the photoacoustic cell which is then sealed for the measurement. The sample may be one solid piece, powder or basically in any form for the measurement. For example, a piece of rock can be inserted into the sample cup and the spectrum measured from it.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>A useful way of analyzing solid samples without the need for cutting samples uses ATR or <a href="/wiki/Attenuated_total_reflectance" title="Attenuated total reflectance">attenuated total reflectance</a> spectroscopy. Using this approach, samples are pressed against the face of a single crystal. The infrared radiation passes through the crystal and only interacts with the sample at the interface between the two materials.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading3"><h3 id="Comparing_to_a_reference">Comparing to a reference</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=9" title="Edit section: Comparing to a reference"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:IR_spectroscopy_apparatus.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/17/IR_spectroscopy_apparatus.svg/330px-IR_spectroscopy_apparatus.svg.png" decoding="async" width="330" height="152" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/17/IR_spectroscopy_apparatus.svg/495px-IR_spectroscopy_apparatus.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/17/IR_spectroscopy_apparatus.svg/660px-IR_spectroscopy_apparatus.svg.png 2x" data-file-width="660" data-file-height="304" /></a><figcaption>Schematics of a two-beam absorption spectrometer. A beam of infrared light is produced, passed through an <a href="/wiki/Monochromator" title="Monochromator">monochromator</a> (not shown), and then split into two separate beams. One is passed through the sample, the other passed through a reference. The beams are both reflected back towards a detector, however first they pass through a splitter, which quickly alternates which of the two beams enters the detector. The two signals are then compared and a printout is obtained. This "two-beam" setup gives accurate spectra even if the intensity of the light source drifts over time.</figcaption></figure> <p>It is typical to record spectrum of both the sample and a "reference". This step controls for a number of variables, e.g. <a href="/wiki/Infrared_detector" title="Infrared detector">infrared detector</a>, which may affect the spectrum. The reference measurement makes it possible to eliminate the instrument influence.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>The appropriate "reference" depends on the measurement and its goal. The simplest reference measurement is to simply remove the sample (replacing it by air). However, sometimes a different reference is more useful. For example, if the sample is a dilute solute dissolved in water in a beaker, then a good reference measurement might be to measure pure water in the same beaker. Then the reference measurement would cancel out not only all the instrumental properties (like what light source is used), but also the light-absorbing and light-reflecting properties of the water and beaker, and the final result would just show the properties of the solute (at least approximately).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>A common way to compare to a reference is sequentially: first measure the reference, then replace the reference by the sample and measure the sample. This technique is not perfectly reliable; if the infrared lamp is a bit brighter during the reference measurement, then a bit dimmer during the sample measurement, the measurement will be distorted. More elaborate methods, such as a "two-beam" setup (see figure), can correct for these types of effects to give very accurate results. The <a href="/wiki/Standard_addition" title="Standard addition">Standard addition</a> method can be used to statistically cancel these errors. </p><p>Nevertheless, among different absorption-based techniques which are used for gaseous species detection, <a href="/wiki/Cavity_ring-down_spectroscopy" title="Cavity ring-down spectroscopy">Cavity ring-down spectroscopy</a> (CRDS) can be used as a calibration-free method. The fact that CRDS is based on the measurements of photon life-times (and not the laser intensity) makes it needless for any calibration and comparison with a reference <sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> </p><p>Some instruments also automatically identify the substance being measured from a store of thousands of reference spectra held in storage. </p> <div class="mw-heading mw-heading3"><h3 id="FTIR">FTIR</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=10" title="Edit section: FTIR"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Fourier_transform_infrared_spectroscopy" class="mw-redirect" title="Fourier transform infrared spectroscopy">Fourier transform infrared spectroscopy</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:FTIR-interferogram.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d4/FTIR-interferogram.svg/220px-FTIR-interferogram.svg.png" decoding="async" width="220" height="163" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d4/FTIR-interferogram.svg/330px-FTIR-interferogram.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d4/FTIR-interferogram.svg/440px-FTIR-interferogram.svg.png 2x" data-file-width="969" data-file-height="720" /></a><figcaption>An interferogram from an <a href="/wiki/FTIR" class="mw-redirect" title="FTIR">FTIR</a> measurement. The horizontal axis is the position of the mirror, and the vertical axis is the amount of light detected. This is the "raw data" which can be <a href="/wiki/Fourier_transform" title="Fourier transform">Fourier transformed</a> to get the actual spectrum.</figcaption></figure> <p><b><a href="/wiki/Fourier_transform" title="Fourier transform">Fourier transform</a> infrared (FTIR) spectroscopy</b> is a measurement technique that allows one to record infrared spectra. Infrared light is guided through an <a href="/wiki/Interferometer" class="mw-redirect" title="Interferometer">interferometer</a> and then through the sample (or vice versa). A moving mirror inside the apparatus alters the distribution of infrared light that passes through the interferometer. The signal directly recorded, called an "interferogram", represents light output as a function of mirror position. A data-processing technique called <a href="/wiki/Fourier_transform" title="Fourier transform">Fourier transform</a> turns this raw data into the desired result (the sample's spectrum): light output as a function of infrared <a href="/wiki/Wavelength" title="Wavelength">wavelength</a> (or equivalently, <a href="/wiki/Wavenumber" title="Wavenumber">wavenumber</a>). As described above, the sample's spectrum is always compared to a reference.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>An alternate method for acquiring spectra is the "dispersive" or "scanning <a href="/wiki/Monochromator" title="Monochromator">monochromator</a>" method. In this approach, the sample is irradiated sequentially with various single wavelengths. The dispersive method is more common in <a href="/wiki/Ultraviolet-visible_spectroscopy" class="mw-redirect" title="Ultraviolet-visible spectroscopy">UV-Vis spectroscopy</a>, but is less practical in the infrared than the FTIR method. One reason that FTIR is favored is called "<a href="/wiki/Fellgett%27s_advantage" title="Fellgett's advantage">Fellgett's advantage</a>" or the "multiplex advantage": The information at all frequencies is collected simultaneously, improving both speed and <a href="/wiki/Signal-to-noise_ratio" title="Signal-to-noise ratio">signal-to-noise ratio</a>. Another is called "Jacquinot's Throughput Advantage": A dispersive measurement requires detecting much lower light levels than an FTIR measurement.<sup id="cite_ref-white_32-0" class="reference"><a href="#cite_note-white-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> There are other advantages, as well as some disadvantages,<sup id="cite_ref-white_32-1" class="reference"><a href="#cite_note-white-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> but virtually all modern infrared spectrometers are FTIR instruments. </p> <div class="mw-heading mw-heading3"><h3 id="Infrared_microscopy">Infrared microscopy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=11" title="Edit section: Infrared microscopy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Various forms of <a href="/wiki/Infrared_microscopy" class="mw-redirect" title="Infrared microscopy">infrared microscopy</a> exist. These include IR versions of sub-diffraction microscopy<sup id="cite_ref-wiley12_33-0" class="reference"><a href="#cite_note-wiley12-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> such as IR <a href="/wiki/Near-field_scanning_optical_microscope" title="Near-field scanning optical microscope">NSOM</a>,<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Photothermal_microspectroscopy" title="Photothermal microspectroscopy">photothermal microspectroscopy</a>, <a href="/wiki/Nano-FTIR" title="Nano-FTIR">Nano-FTIR</a> and <a href="/wiki/AFM-IR" class="mw-redirect" title="AFM-IR">atomic force microscope based infrared spectroscopy</a> (AFM-IR). </p> <div class="mw-heading mw-heading3"><h3 id="Other_methods_in_molecular_vibrational_spectroscopy">Other methods in molecular vibrational spectroscopy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=12" title="Edit section: Other methods in molecular vibrational spectroscopy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Infrared spectroscopy is not the only method of studying molecular vibrational spectra. <a href="/wiki/Raman_spectroscopy" title="Raman spectroscopy">Raman spectroscopy</a> involves an <a href="/wiki/Inelastic_scattering" title="Inelastic scattering">inelastic scattering</a> process in which only part of the energy of an incident photon is absorbed by the molecule, and the remaining part is scattered and detected. The energy difference corresponds to absorbed vibrational energy.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>The <a href="/wiki/Selection_rule" title="Selection rule">selection rules</a> for infrared and for Raman spectroscopy are different at least for some <a href="/wiki/Molecular_symmetry" title="Molecular symmetry">molecular symmetries</a>, so that the two methods are complementary in that they observe vibrations of different symmetries.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p><p>Another method is <a href="/wiki/Electron_energy_loss_spectroscopy" title="Electron energy loss spectroscopy">electron energy loss spectroscopy</a> (EELS), in which the energy absorbed is provided by an inelastically scattered electron rather than a photon. This method is useful for studying vibrations of molecules <a href="/wiki/Adsorption" title="Adsorption">adsorbed</a> on a solid surface. </p><p>Recently, <a href="/wiki/High_resolution_electron_energy_loss_spectroscopy" title="High resolution electron energy loss spectroscopy">high-resolution EELS</a> (HREELS) has emerged as a technique for performing vibrational spectroscopy in a <a href="/wiki/Transmission_electron_microscopy" title="Transmission electron microscopy">transmission electron microscope</a> (TEM).<sup id="cite_ref-:0_35-0" class="reference"><a href="#cite_note-:0-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> In combination with the high spatial resolution of the TEM, unprecedented experiments have been performed, such as nano-scale temperature measurements,<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> mapping of isotopically labeled molecules,<sup id="cite_ref-38" class="reference"><a href="#cite_note-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> mapping of phonon modes in position- and momentum-space,<sup id="cite_ref-39" class="reference"><a href="#cite_note-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> vibrational surface and bulk mode mapping on nanocubes,<sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> and investigations of <a href="/wiki/Polariton" title="Polariton">polariton</a> modes in van der Waals crystals.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> Analysis of vibrational modes that are IR-inactive but appear in <a href="/wiki/Inelastic_neutron_scattering" class="mw-redirect" title="Inelastic neutron scattering">inelastic neutron scattering</a> is also possible at high spatial resolution using EELS.<sup id="cite_ref-43" class="reference"><a href="#cite_note-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> Although the spatial resolution of HREELs is very high, the bands are extremely broad compared to other techniques.<sup id="cite_ref-:0_35-1" class="reference"><a href="#cite_note-:0-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Computational_infrared_microscopy">Computational infrared microscopy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=13" title="Edit section: Computational infrared microscopy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>By using computer <a href="/wiki/Simulation" title="Simulation">simulations</a> and <a href="/wiki/Normal_mode" title="Normal mode">normal mode</a> analysis it is possible to calculate theoretical frequencies of molecules.<sup id="cite_ref-44" class="reference"><a href="#cite_note-44"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Absorption_bands">Absorption bands</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=14" title="Edit section: Absorption bands"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>IR spectroscopy is often used to identify structures because <a href="/wiki/Functional_group" title="Functional group">functional groups</a> give rise to characteristic bands both in terms of intensity and position (frequency). The positions of these bands are summarized in correlation tables as shown below. </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Infrared_spectroscopy_correlation_table" title="Infrared spectroscopy correlation table">Infrared spectroscopy correlation table</a></div> <figure class="mw-halign-center" typeof="mw:File/Thumb"><a href="/wiki/File:IR-spectroscopy-sample.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/IR-spectroscopy-sample.svg/800px-IR-spectroscopy-sample.svg.png" decoding="async" width="800" height="242" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/IR-spectroscopy-sample.svg/1200px-IR-spectroscopy-sample.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d9/IR-spectroscopy-sample.svg/1600px-IR-spectroscopy-sample.svg.png 2x" data-file-width="1524" data-file-height="461" /></a><figcaption>List of main IR spectroscopy bands. For example, the carboxyl group will contain a C = O band at 1700 cm<sup>−1</sup> and an OH band at 3500 cm<sup>−1</sup> (total group -COOH). Wavenumbers listed in <a href="/wiki/Wavenumber" title="Wavenumber">cm<sup>−1</sup></a>.</figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="Regions">Regions</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=15" title="Edit section: Regions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A spectrograph is often interpreted as having two regions.<sup id="cite_ref-OChemSmith3E_45-0" class="reference"><a href="#cite_note-OChemSmith3E-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> </p> <ul><li><b>functional group region</b> <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \geq 1,500{\text{ cm}}^{-1}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>≥</mo> <mn>1</mn> <mo>,</mo> <mn>500</mn> <msup> <mrow class="MJX-TeXAtom-ORD"> <mtext> cm</mtext> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>1</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \geq 1,500{\text{ cm}}^{-1}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/45ee19f967f0975d57baf1b9e3ac155be032a490" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:14.019ex; height:3.009ex;" alt="{\displaystyle \geq 1,500{\text{ cm}}^{-1}}"></span></li></ul> <p>In the functional region there are one to a few troughs per functional group.<sup id="cite_ref-OChemSmith3E_45-1" class="reference"><a href="#cite_note-OChemSmith3E-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> </p> <ul><li><b>fingerprint region</b> <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle <1,500{\text{ cm}}^{-1}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo><</mo> <mn>1</mn> <mo>,</mo> <mn>500</mn> <msup> <mrow class="MJX-TeXAtom-ORD"> <mtext> cm</mtext> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>1</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle <1,500{\text{ cm}}^{-1}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/47c2d0fbc974ed597d6d0a349a0cd8817127ce67" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:14.019ex; height:3.009ex;" alt="{\displaystyle <1,500{\text{ cm}}^{-1}}"></span></li></ul> <p>In the fingerprint region there are many troughs which form an intricate pattern which can be used like a fingerprint to determine the compound.<sup id="cite_ref-OChemSmith3E_45-2" class="reference"><a href="#cite_note-OChemSmith3E-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Badger's_rule"><span id="Badger.27s_rule"></span>Badger's rule</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=16" title="Edit section: Badger's rule"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>For many kinds of samples, the assignments are known, i.e. which bond deformation(s) are associated with which frequency. In such cases further information can be gleaned about the strength on a bond, relying on the empirical guideline called <b>Badger's rule</b>. Originally published by <a href="/wiki/Richard_McLean_Badger" title="Richard McLean Badger">Richard McLean Badger</a> in 1934,<sup id="cite_ref-46" class="reference"><a href="#cite_note-46"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> this rule states that the strength of a bond (in terms of force constant) correlates with the bond length. That is, increase in bond strength leads to corresponding bond shortening and vice versa. </p> <div class="mw-heading mw-heading2"><h2 id="Isotope_effects">Isotope effects</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=17" title="Edit section: Isotope effects"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The different isotopes in a particular species may exhibit different fine details in infrared spectroscopy. For example, the O–O stretching frequency (in reciprocal centimeters) of oxy<a href="/wiki/Hemocyanin" title="Hemocyanin">hemocyanin</a> is experimentally determined to be 832 and 788 cm<sup>−1</sup> for ν(<sup>16</sup>O–<sup>16</sup>O) and ν(<sup>18</sup>O–<sup>18</sup>O), respectively. </p><p>By considering the O–O bond as a spring, the frequency of absorbance can be calculated as a <a href="/wiki/Wavenumber" title="Wavenumber">wavenumber</a> [= frequency/(speed of light)] </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\tilde {\nu }}={\frac {1}{2\pi c}}{\sqrt {\frac {k}{\mu }}}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mover> <mi>ν</mi> <mo stretchy="false">~</mo> </mover> </mrow> </mrow> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>1</mn> <mrow> <mn>2</mn> <mi>π</mi> <mi>c</mi> </mrow> </mfrac> </mrow> <mrow class="MJX-TeXAtom-ORD"> <msqrt> <mfrac> <mi>k</mi> <mi>μ</mi> </mfrac> </msqrt> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle {\tilde {\nu }}={\frac {1}{2\pi c}}{\sqrt {\frac {k}{\mu }}}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/aac8dae70c57c5892051aa0b2fcf7f2d6ffd9f25" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.171ex; width:13.314ex; height:7.509ex;" alt="{\displaystyle {\tilde {\nu }}={\frac {1}{2\pi c}}{\sqrt {\frac {k}{\mu }}}}"></span></dd></dl> <p>where <i>k</i> is the spring constant for the bond, <i>c</i> is the speed of light, and <i>μ</i> is the <a href="/wiki/Reduced_mass" title="Reduced mass">reduced mass</a> of the A–B system: </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mu ={\frac {m_{\mathrm {A} }m_{\mathrm {B} }}{m_{\mathrm {A} }+m_{\mathrm {B} }}}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>μ</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">A</mi> </mrow> </mrow> </msub> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">B</mi> </mrow> </mrow> </msub> </mrow> <mrow> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">A</mi> </mrow> </mrow> </msub> <mo>+</mo> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">B</mi> </mrow> </mrow> </msub> </mrow> </mfrac> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \mu ={\frac {m_{\mathrm {A} }m_{\mathrm {B} }}{m_{\mathrm {A} }+m_{\mathrm {B} }}}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2b4dffffacd712a53835a31052dff2bfa6e47379" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.171ex; width:15.118ex; height:5.009ex;" alt="{\displaystyle \mu ={\frac {m_{\mathrm {A} }m_{\mathrm {B} }}{m_{\mathrm {A} }+m_{\mathrm {B} }}}}"></span></dd></dl> <p>(<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle m_{i}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>i</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle m_{i}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/95ec8e804f69706d3f5ad235f4f983220c8df7c2" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.84ex; height:2.009ex;" alt="{\displaystyle m_{i}}"></span> is the mass of atom <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle i}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>i</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle i}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/add78d8608ad86e54951b8c8bd6c8d8416533d20" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.802ex; height:2.176ex;" alt="{\displaystyle i}"></span>). </p><p>The reduced masses for <sup>16</sup>O–<sup>16</sup>O and <sup>18</sup>O–<sup>18</sup>O can be approximated as 8 and 9 respectively. Thus </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\frac {{\tilde {\nu }}(^{16}\mathrm {O} )}{{\tilde {\nu }}(^{18}\mathrm {O} )}}={\sqrt {\frac {9}{8}}}\approx {\frac {832}{788}}.}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mover> <mi>ν</mi> <mo stretchy="false">~</mo> </mover> </mrow> </mrow> <msup> <mo stretchy="false">(</mo> <mrow class="MJX-TeXAtom-ORD"> <mn>16</mn> </mrow> </msup> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">O</mi> </mrow> <mo stretchy="false">)</mo> </mrow> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mover> <mi>ν</mi> <mo stretchy="false">~</mo> </mover> </mrow> </mrow> <msup> <mo stretchy="false">(</mo> <mrow class="MJX-TeXAtom-ORD"> <mn>18</mn> </mrow> </msup> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">O</mi> </mrow> <mo stretchy="false">)</mo> </mrow> </mfrac> </mrow> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <msqrt> <mfrac> <mn>9</mn> <mn>8</mn> </mfrac> </msqrt> </mrow> <mo>≈</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mn>832</mn> <mn>788</mn> </mfrac> </mrow> <mo>.</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle {\frac {{\tilde {\nu }}(^{16}\mathrm {O} )}{{\tilde {\nu }}(^{18}\mathrm {O} )}}={\sqrt {\frac {9}{8}}}\approx {\frac {832}{788}}.}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2e51452ac4b9a4e666c47b9bbd3c7d4c85df9857" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.671ex; width:23.136ex; height:6.676ex;" alt="{\displaystyle {\frac {{\tilde {\nu }}(^{16}\mathrm {O} )}{{\tilde {\nu }}(^{18}\mathrm {O} )}}={\sqrt {\frac {9}{8}}}\approx {\frac {832}{788}}.}"></span></dd></dl> <p>The effect of isotopes, both on the vibration and the decay dynamics, has been found to be stronger than previously thought. In some systems, such as silicon and germanium, the decay of the anti-symmetric stretch mode of interstitial oxygen involves the symmetric stretch mode with a strong isotope dependence. For example, it was shown that for a natural silicon sample, the lifetime of the anti-symmetric vibration is 11.4 ps. When the isotope of one of the silicon atoms is increased to <sup>29</sup>Si, the lifetime increases to 19 ps. In similar manner, when the silicon atom is changed to <sup>30</sup>Si, the lifetime becomes 27 ps.<sup id="cite_ref-47" class="reference"><a href="#cite_note-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Two-dimensional_IR">Two-dimensional IR</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=18" title="Edit section: Two-dimensional IR"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><b>Two-dimensional infrared correlation spectroscopy analysis</b> combines multiple samples of infrared spectra to reveal more complex properties. By extending the spectral information of a perturbed sample, spectral analysis is simplified and resolution is enhanced. The 2D synchronous and 2D asynchronous spectra represent a graphical overview of the spectral changes due to a perturbation (such as a changing concentration or changing temperature) as well as the relationship between the spectral changes at two different wavenumbers.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2024)">citation needed</span></a></i>]</sup> </p> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Two-dimensional_infrared_spectroscopy" title="Two-dimensional infrared spectroscopy">Two-dimensional infrared spectroscopy</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:2dir_pulse_sequence_newversion.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cc/2dir_pulse_sequence_newversion.png/280px-2dir_pulse_sequence_newversion.png" decoding="async" width="280" height="141" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cc/2dir_pulse_sequence_newversion.png/420px-2dir_pulse_sequence_newversion.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cc/2dir_pulse_sequence_newversion.png/560px-2dir_pulse_sequence_newversion.png 2x" data-file-width="800" data-file-height="404" /></a><figcaption>Pulse Sequence used to obtain a two-dimensional Fourier transform infrared spectrum. The time period <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{1}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>τ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \tau _{1}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/ef3e70085bbfec0d2ed0f898618bbb48db4ab7b1" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.07ex; height:2.009ex;" alt="{\displaystyle \tau _{1}}"></span> is usually referred to as the coherence time and the second time period <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{2}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>τ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \tau _{2}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/236a07f6109f6e8c7dd3d9229ab240a983045cd8" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.07ex; height:2.009ex;" alt="{\displaystyle \tau _{2}}"></span> is known as the waiting time. The excitation frequency is obtained by Fourier transforming along the <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \tau _{1}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>τ</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \tau _{1}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/ef3e70085bbfec0d2ed0f898618bbb48db4ab7b1" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.07ex; height:2.009ex;" alt="{\displaystyle \tau _{1}}"></span> axis.</figcaption></figure> <p><b>Nonlinear two-dimensional infrared spectroscopy</b><sup id="cite_ref-48" class="reference"><a href="#cite_note-48"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-49" class="reference"><a href="#cite_note-49"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup> is the infrared version of <a href="/wiki/Correlation_spectroscopy" class="mw-redirect" title="Correlation spectroscopy">correlation spectroscopy</a>. Nonlinear two-dimensional infrared spectroscopy is a technique that has become available with the development of <a href="/wiki/Femtosecond" title="Femtosecond">femtosecond</a> infrared laser pulses. In this experiment, first a set of pump pulses is applied to the sample. This is followed by a waiting time during which the system is allowed to relax. The typical waiting time lasts from zero to several picoseconds, and the duration can be controlled with a resolution of tens of femtoseconds. A probe pulse is then applied, resulting in the emission of a signal from the sample. The nonlinear two-dimensional infrared spectrum is a two-dimensional correlation plot of the frequency ω<sub>1</sub> that was excited by the initial pump pulses and the frequency ω<sub>3</sub> excited by the probe pulse after the waiting time. This allows the observation of coupling between different vibrational modes; because of its extremely fine time resolution, it can be used to monitor molecular dynamics on a picosecond timescale. It is still a largely unexplored technique and is becoming increasingly popular for fundamental research. </p><p>As with two-dimensional nuclear magnetic resonance (<a href="/wiki/2DNMR" class="mw-redirect" title="2DNMR">2DNMR</a>) spectroscopy, this technique spreads the spectrum in two dimensions and allows for the observation of cross peaks that contain information on the coupling between different modes. In contrast to 2DNMR, nonlinear two-dimensional infrared spectroscopy also involves the excitation to overtones. These excitations result in excited state absorption peaks located below the diagonal and cross peaks. In 2DNMR, two distinct techniques, <a href="/wiki/Correlation_spectroscopy#COSY" class="mw-redirect" title="Correlation spectroscopy">COSY</a> and <a href="/wiki/Correlation_spectroscopy#Nuclear_Overhauser_effect_spectroscopy_(NOESY)" class="mw-redirect" title="Correlation spectroscopy">NOESY</a>, are frequently used. The cross peaks in the first are related to the scalar coupling, while in the latter they are related to the spin transfer between different nuclei. In nonlinear two-dimensional infrared spectroscopy, analogs have been drawn to these 2DNMR techniques. Nonlinear two-dimensional infrared spectroscopy with zero waiting time corresponds to COSY, and nonlinear two-dimensional infrared spectroscopy with finite waiting time allowing vibrational population transfer corresponds to NOESY. The COSY variant of nonlinear two-dimensional infrared spectroscopy has been used for determination of the secondary structure content of proteins.<sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=19" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col" style="column-width: 28em;"> <ul><li><a href="/wiki/Applied_spectroscopy" title="Applied spectroscopy">Applied spectroscopy</a></li> <li><a href="/wiki/Astrochemistry" title="Astrochemistry">Astrochemistry</a></li> <li><a href="/wiki/Atomic_and_molecular_astrophysics" title="Atomic and molecular astrophysics">Atomic and molecular astrophysics</a></li> <li><a href="/wiki/AFM-IR" class="mw-redirect" title="AFM-IR">Atomic force microscopy based infrared spectroscopy (AFM-IR)</a></li> <li><a href="/wiki/Cosmochemistry" title="Cosmochemistry">Cosmochemistry</a></li> <li><a href="/wiki/Far-infrared_astronomy" title="Far-infrared astronomy">Far-infrared astronomy</a></li> <li><a href="/wiki/Forensic_chemistry" title="Forensic chemistry">Forensic chemistry</a></li> <li><a href="/wiki/Forensic_engineering" title="Forensic engineering">Forensic engineering</a></li> <li><a href="/wiki/Forensic_polymer_engineering" title="Forensic polymer engineering">Forensic polymer engineering</a></li> <li><a href="/wiki/Infrared_astronomy" title="Infrared astronomy">Infrared astronomy</a></li> <li><a href="/wiki/Microscopy#Infrared_microscopy" title="Microscopy">Infrared microscopy</a></li> <li><a href="/wiki/Infrared_multiphoton_dissociation" title="Infrared multiphoton dissociation">Infrared multiphoton dissociation</a></li> <li><a href="/wiki/Infrared_photodissociation_spectroscopy" title="Infrared photodissociation spectroscopy">Infrared photodissociation spectroscopy</a></li> <li><a href="/wiki/Infrared_spectroscopy_correlation_table" title="Infrared spectroscopy correlation table">Infrared spectroscopy correlation table</a></li> <li><a href="/wiki/Infrared_spectroscopy_of_metal_carbonyls" class="mw-redirect" title="Infrared spectroscopy of metal carbonyls">Infrared spectroscopy of metal carbonyls</a></li> <li><a href="/wiki/Near-infrared_spectroscopy" title="Near-infrared spectroscopy">Near-infrared spectroscopy</a></li> <li><a href="/wiki/Nuclear_resonance_vibrational_spectroscopy" title="Nuclear resonance vibrational spectroscopy">Nuclear resonance vibrational spectroscopy</a></li> <li><a href="/wiki/Photothermal_microspectroscopy" title="Photothermal microspectroscopy">Photothermal microspectroscopy</a></li> <li><a href="/wiki/Raman_spectroscopy" title="Raman spectroscopy">Raman spectroscopy</a></li> <li><a href="/wiki/Rotational-vibrational_spectroscopy" class="mw-redirect" title="Rotational-vibrational spectroscopy">Rotational-vibrational spectroscopy</a></li> <li><a href="/wiki/Time-resolved_spectroscopy" title="Time-resolved spectroscopy">Time-resolved spectroscopy</a></li> <li><a href="/wiki/Vibrational_spectroscopy_of_linear_molecules" title="Vibrational spectroscopy of linear molecules">Vibrational spectroscopy of linear molecules</a></li></ul> </div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=20" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFZeitlerTadayNewnhamPepper2007" class="citation journal cs1">Zeitler JA, Taday PF, Newnham DA, Pepper M, Gordon KC, Rades T (February 2007). "Terahertz pulsed spectroscopy and imaging in the pharmaceutical setting--a review". <i>The Journal of Pharmacy and Pharmacology</i>. <b>59</b> (2): 209–23. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1211%2Fjpp.59.2.0008">10.1211/jpp.59.2.0008</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/17270075">17270075</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:34705104">34705104</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Journal+of+Pharmacy+and+Pharmacology&rft.atitle=Terahertz+pulsed+spectroscopy+and+imaging+in+the+pharmaceutical+setting--a+review&rft.volume=59&rft.issue=2&rft.pages=209-23&rft.date=2007-02&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A34705104%23id-name%3DS2CID&rft_id=info%3Apmid%2F17270075&rft_id=info%3Adoi%2F10.1211%2Fjpp.59.2.0008&rft.aulast=Zeitler&rft.aufirst=JA&rft.au=Taday%2C+PF&rft.au=Newnham%2C+DA&rft.au=Pepper%2C+M&rft.au=Gordon%2C+KC&rft.au=Rades%2C+T&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-ColourLex-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-ColourLex_2-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://colourlex.com/project/infrared-spectroscopy/">"Infrared Spectroscopy"</a>. <i>ColourLex</i>. 12 March 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">19 January</span> 2022</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=ColourLex&rft.atitle=Infrared+Spectroscopy&rft.date=2021-03-12&rft_id=https%3A%2F%2Fcolourlex.com%2Fproject%2Finfrared-spectroscopy%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDerrickStulikLandry1999" class="citation book cs1">Derrick MR, Stulik D, Landry JM (1999). <a rel="nofollow" class="external text" href="http://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/infrared_spectroscopy.pdf"><i>Infrared Spectroscopy in Conservation Science</i></a> <span class="cs1-format">(PDF)</span>. Scientific Tools for Conservation. Getty Publications. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-89236-469-6" title="Special:BookSources/0-89236-469-6"><bdi>0-89236-469-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Infrared+Spectroscopy+in+Conservation+Science&rft.series=Scientific+Tools+for+Conservation&rft.pub=Getty+Publications&rft.date=1999&rft.isbn=0-89236-469-6&rft.aulast=Derrick&rft.aufirst=MR&rft.au=Stulik%2C+D&rft.au=Landry%2C+JM&rft_id=http%3A%2F%2Fwww.getty.edu%2Fconservation%2Fpublications_resources%2Fpdf_publications%2Fpdf%2Finfrared_spectroscopy.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRicciardi" class="citation web cs1">Ricciardi P. <a rel="nofollow" class="external text" href="http://www.labnews.co.uk/features/unlocking-the-secrets-of-illuminated-manuscripts-08-11-2012/">"Unlocking the secrets of illuminated manuscripts"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">11 December</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Unlocking+the+secrets+of+illuminated+manuscripts&rft.aulast=Ricciardi&rft.aufirst=Paola&rft_id=http%3A%2F%2Fwww.labnews.co.uk%2Ffeatures%2Funlocking-the-secrets-of-illuminated-manuscripts-08-11-2012%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLau1999" class="citation book cs1">Lau WS (1999). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=rotNlJDFJWsC"><i>Infrared characterization for microelectronics</i></a>. World Scientific. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-981-02-2352-6" title="Special:BookSources/978-981-02-2352-6"><bdi>978-981-02-2352-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Infrared+characterization+for+microelectronics&rft.pub=World+Scientific&rft.date=1999&rft.isbn=978-981-02-2352-6&rft.aulast=Lau&rft.aufirst=WS&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DrotNlJDFJWsC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFOsborne2006" class="citation encyclopaedia cs1">Osborne BG (2006). "Near-Infrared Spectroscopy in Food Analysis". <i>Encyclopedia of Analytical Chemistry</i>. John Wiley & Sons. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2F9780470027318.a1018">10.1002/9780470027318.a1018</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780470027318" title="Special:BookSources/9780470027318"><bdi>9780470027318</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Near-Infrared+Spectroscopy+in+Food+Analysis&rft.btitle=Encyclopedia+of+Analytical+Chemistry&rft.pub=John+Wiley+%26+Sons&rft.date=2006&rft_id=info%3Adoi%2F10.1002%2F9780470027318.a1018&rft.isbn=9780470027318&rft.aulast=Osborne&rft.aufirst=Brian+G.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFVillarGorritxategiAranzabeFernández2012" class="citation journal cs1">Villar A, Gorritxategi E, Aranzabe E, Fernández S, Otaduy D, Fernández LA (December 2012). "Low-cost visible-near infrared sensor for on-line monitoring of fat and fatty acids content during the manufacturing process of the milk". <i>Food Chemistry</i>. <b>135</b> (4): 2756–60. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.foodchem.2012.07.074">10.1016/j.foodchem.2012.07.074</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/22980869">22980869</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Food+Chemistry&rft.atitle=Low-cost+visible-near+infrared+sensor+for+on-line+monitoring+of+fat+and+fatty+acids+content+during+the+manufacturing+process+of+the+milk&rft.volume=135&rft.issue=4&rft.pages=2756-60&rft.date=2012-12&rft_id=info%3Adoi%2F10.1016%2Fj.foodchem.2012.07.074&rft_id=info%3Apmid%2F22980869&rft.aulast=Villar&rft.aufirst=A&rft.au=Gorritxategi%2C+E&rft.au=Aranzabe%2C+E&rft.au=Fern%C3%A1ndez%2C+S&rft.au=Otaduy%2C+D&rft.au=Fern%C3%A1ndez%2C+LA&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFwww.TRMThemes.com" class="citation web cs1">www.TRMThemes.com, TRM Theme by. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20220120030138/https://heathus.com/product_category/gas/infrared-ir-optical-based/">"Infrared (IR) / Optical Based Archives - Heath Consultants"</a>. <i>Heath Consultants</i>. Archived from <a rel="nofollow" class="external text" href="http://heathus.com/product_category/gas/infrared-ir-optical-based/">the original</a> on 2022-01-20<span class="reference-accessdate">. Retrieved <span class="nowrap">2016-04-12</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Heath+Consultants&rft.atitle=Infrared+%28IR%29+%2F+Optical+Based+Archives+-+Heath+Consultants&rft.aulast=www.TRMThemes.com&rft.aufirst=TRM+Theme+by&rft_id=http%3A%2F%2Fheathus.com%2Fproduct_category%2Fgas%2Finfrared-ir-optical-based%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBeckerSachsenheimerKlemenz2017" class="citation journal cs1">Becker, Wolfgang; Sachsenheimer, Kerstin; Klemenz, Melanie (2017). <a rel="nofollow" class="external text" href="https://www.mdpi.com/2073-4360/9/9/435/pdf">"Detection of Black Plastics in the Middle Infrared Spectrum (MIR) Using Photon Up-Conversion Technique for Polymer Recycling Process"</a>. <i>Polymers</i>. <b>9</b> (9). MDPI. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.3390%2Fpolym9090435">10.3390/polym9090435</a></span>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6418689">6418689</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30965736">30965736</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Polymers&rft.atitle=Detection+of+Black+Plastics+in+the+Middle+Infrared+Spectrum+%28MIR%29+Using+Photon+Up-Conversion+Technique+for+Polymer+Recycling+Process&rft.volume=9&rft.issue=9&rft.date=2017&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC6418689%23id-name%3DPMC&rft_id=info%3Apmid%2F30965736&rft_id=info%3Adoi%2F10.3390%2Fpolym9090435&rft.aulast=Becker&rft.aufirst=Wolfgang&rft.au=Sachsenheimer%2C+Kerstin&rft.au=Klemenz%2C+Melanie&rft_id=https%3A%2F%2Fwww.mdpi.com%2F2073-4360%2F9%2F9%2F435%2Fpdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPerry2017" class="citation web cs1">Perry, Tekla S. (2017-03-14). <a rel="nofollow" class="external text" href="https://spectrum.ieee.org/israeli-startup-consumer-physics-says-its-scio-food-analyzer-is-finally-ready-for-prime-timeso-we-took-it-grocery-shopping">"What Happened When We Took the SCiO Food Analyzer Grocery Shopping"</a>. <i>IEEE Spectrum: Technology, Engineering, and Science News</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2017-03-23</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=IEEE+Spectrum%3A+Technology%2C+Engineering%2C+and+Science+News&rft.atitle=What+Happened+When+We+Took+the+SCiO+Food+Analyzer+Grocery+Shopping&rft.date=2017-03-14&rft.aulast=Perry&rft.aufirst=Tekla+S.&rft_id=https%3A%2F%2Fspectrum.ieee.org%2Fisraeli-startup-consumer-physics-says-its-scio-food-analyzer-is-finally-ready-for-prime-timeso-we-took-it-grocery-shopping&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCoates2014" class="citation web cs1">Coates, John (18 June 2014). <a rel="nofollow" class="external text" href="http://www.americanpharmaceuticalreview.com/Featured-Articles/163573-A-Review-of-New-Small-Scale-Technologies-for-Near-Infrared-Measurements/">"A Review of New Small-Scale Technologies for Near Infrared Measurements"</a>. <i>American Pharmaceutical Review</i>. Coates Consulting LLC<span class="reference-accessdate">. Retrieved <span class="nowrap">2017-03-23</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=American+Pharmaceutical+Review&rft.atitle=A+Review+of+New+Small-Scale+Technologies+for+Near+Infrared+Measurements&rft.date=2014-06-18&rft.aulast=Coates&rft.aufirst=John&rft_id=http%3A%2F%2Fwww.americanpharmaceuticalreview.com%2FFeatured-Articles%2F163573-A-Review-of-New-Small-Scale-Technologies-for-Near-Infrared-Measurements%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBoosaVarimallaDumpalapallyGutta2021" class="citation journal cs1">Boosa, Venu; Varimalla, Shirisha; Dumpalapally, Mahesh; Gutta, Naresh; Velisoju, Vijay Kumar; Nama, Narender; Akula, Venugopal (2021-09-05). <a rel="nofollow" class="external text" href="https://www.sciencedirect.com/science/article/pii/S0926337321003039">"Influence of Brønsted acid sites on chemoselective synthesis of pyrrolidones over H-ZSM-5 supported copper catalyst"</a>. <i>Applied Catalysis B: Environmental</i>. <b>292</b>: 120177. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2021AppCB.29220177B">2021AppCB.29220177B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.apcatb.2021.120177">10.1016/j.apcatb.2021.120177</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0926-3373">0926-3373</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+Catalysis+B%3A+Environmental&rft.atitle=Influence+of+Br%C3%B8nsted+acid+sites+on+chemoselective+synthesis+of+pyrrolidones+over+H-ZSM-5+supported+copper+catalyst&rft.volume=292&rft.pages=120177&rft.date=2021-09-05&rft.issn=0926-3373&rft_id=info%3Adoi%2F10.1016%2Fj.apcatb.2021.120177&rft_id=info%3Abibcode%2F2021AppCB.29220177B&rft.aulast=Boosa&rft.aufirst=Venu&rft.au=Varimalla%2C+Shirisha&rft.au=Dumpalapally%2C+Mahesh&rft.au=Gutta%2C+Naresh&rft.au=Velisoju%2C+Vijay+Kumar&rft.au=Nama%2C+Narender&rft.au=Akula%2C+Venugopal&rft_id=https%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS0926337321003039&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFajdek-BiedaWróblewskaMiądlickiTołpa2021" class="citation journal cs1">Fajdek-Bieda, Anna; Wróblewska, Agnieszka; Miądlicki, Piotr; Tołpa, Jadwiga; Michalkiewicz, Beata (2021-08-01). <a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs11144-021-02027-3">"Clinoptilolite as a natural, active zeolite catalyst for the chemical transformations of geraniol"</a>. <i>Reaction Kinetics, Mechanisms and Catalysis</i>. <b>133</b> (2): 997–1011. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs11144-021-02027-3">10.1007/s11144-021-02027-3</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1878-5204">1878-5204</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:236149569">236149569</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Reaction+Kinetics%2C+Mechanisms+and+Catalysis&rft.atitle=Clinoptilolite+as+a+natural%2C+active+zeolite+catalyst+for+the+chemical+transformations+of+geraniol&rft.volume=133&rft.issue=2&rft.pages=997-1011&rft.date=2021-08-01&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A236149569%23id-name%3DS2CID&rft.issn=1878-5204&rft_id=info%3Adoi%2F10.1007%2Fs11144-021-02027-3&rft.aulast=Fajdek-Bieda&rft.aufirst=Anna&rft.au=Wr%C3%B3blewska%2C+Agnieszka&rft.au=Mi%C4%85dlicki%2C+Piotr&rft.au=To%C5%82pa%2C+Jadwiga&rft.au=Michalkiewicz%2C+Beata&rft_id=https%3A%2F%2Fdoi.org%2F10.1007%252Fs11144-021-02027-3&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAzancotBobadillaCentenoOdriozola2021" class="citation journal cs1">Azancot, Lola; Bobadilla, Luis F.; Centeno, Miguel A.; Odriozola, José A. (2021-05-15). <a rel="nofollow" class="external text" href="https://www.sciencedirect.com/science/article/pii/S092633732031239X">"IR spectroscopic insights into the coking-resistance effect of potassium on nickel-based catalyst during dry reforming of methane"</a>. <i>Applied Catalysis B: Environmental</i>. <b>285</b>: 119822. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2021AppCB.28519822A">2021AppCB.28519822A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.apcatb.2020.119822">10.1016/j.apcatb.2020.119822</a>. <a href="/wiki/Hdl_(identifier)" class="mw-redirect" title="Hdl (identifier)">hdl</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://hdl.handle.net/10261%2F251396">10261/251396</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0926-3373">0926-3373</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:232627637">232627637</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+Catalysis+B%3A+Environmental&rft.atitle=IR+spectroscopic+insights+into+the+coking-resistance+effect+of+potassium+on+nickel-based+catalyst+during+dry+reforming+of+methane&rft.volume=285&rft.pages=119822&rft.date=2021-05-15&rft_id=info%3Ahdl%2F10261%2F251396&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A232627637%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2021AppCB.28519822A&rft.issn=0926-3373&rft_id=info%3Adoi%2F10.1016%2Fj.apcatb.2020.119822&rft.aulast=Azancot&rft.aufirst=Lola&rft.au=Bobadilla%2C+Luis+F.&rft.au=Centeno%2C+Miguel+A.&rft.au=Odriozola%2C+Jos%C3%A9+A.&rft_id=https%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fpii%2FS092633732031239X&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNuguidElsenerFerriKröcher2021" class="citation journal cs1">Nuguid, Rob Jeremiah G.; Elsener, Martin; Ferri, Davide; Kröcher, Oliver (2021-12-05). <a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.apcatb.2021.120629">"Operando diffuse reflectance infrared detection of cyanide intermediate species during the reaction of formaldehyde with ammonia over V2O5/WO3-TiO2"</a>. <i>Applied Catalysis B: Environmental</i>. <b>298</b>: 120629. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.apcatb.2021.120629">10.1016/j.apcatb.2021.120629</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0926-3373">0926-3373</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+Catalysis+B%3A+Environmental&rft.atitle=Operando+diffuse+reflectance+infrared+detection+of+cyanide+intermediate+species+during+the+reaction+of+formaldehyde+with+ammonia+over+V2O5%2FWO3-TiO2&rft.volume=298&rft.pages=120629&rft.date=2021-12-05&rft_id=info%3Adoi%2F10.1016%2Fj.apcatb.2021.120629&rft.issn=0926-3373&rft.aulast=Nuguid&rft.aufirst=Rob+Jeremiah+G.&rft.au=Elsener%2C+Martin&rft.au=Ferri%2C+Davide&rft.au=Kr%C3%B6cher%2C+Oliver&rft_id=https%3A%2F%2Fdoi.org%2F10.1016%252Fj.apcatb.2021.120629&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSockalingumBouhedjaPinaAllouch1998" class="citation journal cs1">Sockalingum, G. D.; Bouhedja, W.; Pina, P.; Allouch, P.; Bloy, C.; Manfait, M. (February 1998). <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/9551657">"FT-IR spectroscopy as an emerging method for rapid characterization of microorganisms"</a>. <i>Cellular and Molecular Biology (Noisy-Le-Grand, France)</i>. <b>44</b> (1): 261–269. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0145-5680">0145-5680</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/9551657">9551657</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Cellular+and+Molecular+Biology+%28Noisy-Le-Grand%2C+France%29&rft.atitle=FT-IR+spectroscopy+as+an+emerging+method+for+rapid+characterization+of+microorganisms&rft.volume=44&rft.issue=1&rft.pages=261-269&rft.date=1998-02&rft_id=info%3Apmid%2F9551657&rft.issn=0145-5680&rft.aulast=Sockalingum&rft.aufirst=G.+D.&rft.au=Bouhedja%2C+W.&rft.au=Pina%2C+P.&rft.au=Allouch%2C+P.&rft.au=Bloy%2C+C.&rft.au=Manfait%2C+M.&rft_id=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F9551657&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHelmLabischinskiSchallehnNaumann1991" class="citation journal cs1">Helm, D.; Labischinski, H.; Schallehn, Gisela; Naumann, D. (1991-01-01). <a rel="nofollow" class="external text" href="https://doi.org/10.1099%2F00221287-137-1-69">"Classification and identification of bacteria by Fourier-transform infrared spectroscopy"</a>. <i>Microbiology</i>. <b>137</b> (1): 69–79. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1099%2F00221287-137-1-69">10.1099/00221287-137-1-69</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1350-0872">1350-0872</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/1710644">1710644</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Microbiology&rft.atitle=Classification+and+identification+of+bacteria+by+Fourier-transform+infrared+spectroscopy&rft.volume=137&rft.issue=1&rft.pages=69-79&rft.date=1991-01-01&rft.issn=1350-0872&rft_id=info%3Apmid%2F1710644&rft_id=info%3Adoi%2F10.1099%2F00221287-137-1-69&rft.aulast=Helm&rft.aufirst=D.&rft.au=Labischinski%2C+H.&rft.au=Schallehn%2C+Gisela&rft.au=Naumann%2C+D.&rft_id=https%3A%2F%2Fdoi.org%2F10.1099%252F00221287-137-1-69&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHoltHirstSutherlandMacDonald1995" class="citation journal cs1">Holt, C; Hirst, D; Sutherland, A; MacDonald, F (January 1995). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC167294">"Discrimination of species in the genus Listeria by Fourier transform infrared spectroscopy and canonical variate analysis"</a>. <i>Applied and Environmental Microbiology</i>. <b>61</b> (1): 377–378. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1995ApEnM..61..377H">1995ApEnM..61..377H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1128%2Faem.61.1.377-378.1995">10.1128/aem.61.1.377-378.1995</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0099-2240">0099-2240</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC167294">167294</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/7887620">7887620</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+and+Environmental+Microbiology&rft.atitle=Discrimination+of+species+in+the+genus+Listeria+by+Fourier+transform+infrared+spectroscopy+and+canonical+variate+analysis&rft.volume=61&rft.issue=1&rft.pages=377-378&rft.date=1995-01&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC167294%23id-name%3DPMC&rft_id=info%3Abibcode%2F1995ApEnM..61..377H&rft_id=info%3Apmid%2F7887620&rft_id=info%3Adoi%2F10.1128%2Faem.61.1.377-378.1995&rft.issn=0099-2240&rft.aulast=Holt&rft.aufirst=C&rft.au=Hirst%2C+D&rft.au=Sutherland%2C+A&rft.au=MacDonald%2C+F&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC167294&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCamposSousaMourãoLopes2018" class="citation journal cs1">Campos, Joana; Sousa, Clara; Mourão, Joana; Lopes, João; Antunes, Patrícia; Peixe, Luísa (November 2018). <a rel="nofollow" class="external text" href="https://linkinghub.elsevier.com/retrieve/pii/S0168160518303465">"Discrimination of non-typhoid Salmonella serogroups and serotypes by Fourier Transform Infrared Spectroscopy: A comprehensive analysis"</a>. <i>International Journal of Food Microbiology</i>. <b>285</b>: 34–41. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.ijfoodmicro.2018.07.005">10.1016/j.ijfoodmicro.2018.07.005</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30015261">30015261</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Food+Microbiology&rft.atitle=Discrimination+of+non-typhoid+Salmonella+serogroups+and+serotypes+by+Fourier+Transform+Infrared+Spectroscopy%3A+A+comprehensive+analysis&rft.volume=285&rft.pages=34-41&rft.date=2018-11&rft_id=info%3Adoi%2F10.1016%2Fj.ijfoodmicro.2018.07.005&rft_id=info%3Apmid%2F30015261&rft.aulast=Campos&rft.aufirst=Joana&rft.au=Sousa%2C+Clara&rft.au=Mour%C3%A3o%2C+Joana&rft.au=Lopes%2C+Jo%C3%A3o&rft.au=Antunes%2C+Patr%C3%ADcia&rft.au=Peixe%2C+Lu%C3%ADsa&rft_id=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0168160518303465&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSharahaRodriguez-DiazSagiRiesenberg2019" class="citation journal cs1">Sharaha, Uraib; Rodriguez-Diaz, Eladio; Sagi, Orli; Riesenberg, Klaris; Salman, Ahmad; Bigio, Irving J.; Huleihel, Mahmoud (July 2019). <a rel="nofollow" class="external text" href="https://onlinelibrary.wiley.com/doi/10.1002/jbio.201800478">"Fast and reliable determination of Escherichia coli susceptibility to antibiotics: Infrared microscopy in tandem with machine learning algorithms"</a>. <i>Journal of Biophotonics</i>. <b>12</b> (7): e201800478. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fjbio.201800478">10.1002/jbio.201800478</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1864-063X">1864-063X</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30916881">30916881</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Biophotonics&rft.atitle=Fast+and+reliable+determination+of+Escherichia+coli+susceptibility+to+antibiotics%3A+Infrared+microscopy+in+tandem+with+machine+learning+algorithms&rft.volume=12&rft.issue=7&rft.pages=e201800478&rft.date=2019-07&rft.issn=1864-063X&rft_id=info%3Apmid%2F30916881&rft_id=info%3Adoi%2F10.1002%2Fjbio.201800478&rft.aulast=Sharaha&rft.aufirst=Uraib&rft.au=Rodriguez-Diaz%2C+Eladio&rft.au=Sagi%2C+Orli&rft.au=Riesenberg%2C+Klaris&rft.au=Salman%2C+Ahmad&rft.au=Bigio%2C+Irving+J.&rft.au=Huleihel%2C+Mahmoud&rft_id=https%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fjbio.201800478&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWijesingheHareMohamedShah2021" class="citation journal cs1">Wijesinghe, Hewa G. S.; Hare, Dominic J.; Mohamed, Ahmed; Shah, Alok K.; Harris, Patrick N. A.; Hill, Michelle M. (2021). <a rel="nofollow" class="external text" href="http://xlink.rsc.org/?DOI=D1AN00546D">"Detecting antimicrobial resistance in Escherichia coli using benchtop attenuated total reflectance-Fourier transform infrared spectroscopy and machine learning"</a>. <i>The Analyst</i>. <b>146</b> (20): 6211–6219. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2021Ana...146.6211W">2021Ana...146.6211W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1039%2FD1AN00546D">10.1039/D1AN00546D</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0003-2654">0003-2654</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/34522918">34522918</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Analyst&rft.atitle=Detecting+antimicrobial+resistance+in+Escherichia+coli+using+benchtop+attenuated+total+reflectance-Fourier+transform+infrared+spectroscopy+and+machine+learning&rft.volume=146&rft.issue=20&rft.pages=6211-6219&rft.date=2021&rft_id=info%3Adoi%2F10.1039%2FD1AN00546D&rft.issn=0003-2654&rft_id=info%3Apmid%2F34522918&rft_id=info%3Abibcode%2F2021Ana...146.6211W&rft.aulast=Wijesinghe&rft.aufirst=Hewa+G.+S.&rft.au=Hare%2C+Dominic+J.&rft.au=Mohamed%2C+Ahmed&rft.au=Shah%2C+Alok+K.&rft.au=Harris%2C+Patrick+N.+A.&rft.au=Hill%2C+Michelle+M.&rft_id=http%3A%2F%2Fxlink.rsc.org%2F%3FDOI%3DD1AN00546D&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSuleimanAbu-AqilSharahaRiesenberg2022" class="citation journal cs1">Suleiman, Manal; Abu-Aqil, George; Sharaha, Uraib; Riesenberg, Klaris; Lapidot, Itshak; Salman, Ahmad; Huleihel, Mahmoud (June 2022). <a rel="nofollow" class="external text" href="https://linkinghub.elsevier.com/retrieve/pii/S1386142522002281">"Infra-red spectroscopy combined with machine learning algorithms enables early determination of Pseudomonas aeruginosa's susceptibility to antibiotics"</a>. <i>Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy</i>. <b>274</b>: 121080. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2022AcSpA.27421080S">2022AcSpA.27421080S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.saa.2022.121080">10.1016/j.saa.2022.121080</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/35248858">35248858</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Spectrochimica+Acta+Part+A%3A+Molecular+and+Biomolecular+Spectroscopy&rft.atitle=Infra-red+spectroscopy+combined+with+machine+learning+algorithms+enables+early+determination+of+Pseudomonas+aeruginosa%27s+susceptibility+to+antibiotics&rft.volume=274&rft.pages=121080&rft.date=2022-06&rft_id=info%3Apmid%2F35248858&rft_id=info%3Adoi%2F10.1016%2Fj.saa.2022.121080&rft_id=info%3Abibcode%2F2022AcSpA.27421080S&rft.aulast=Suleiman&rft.aufirst=Manal&rft.au=Abu-Aqil%2C+George&rft.au=Sharaha%2C+Uraib&rft.au=Riesenberg%2C+Klaris&rft.au=Lapidot%2C+Itshak&rft.au=Salman%2C+Ahmad&rft.au=Huleihel%2C+Mahmoud&rft_id=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1386142522002281&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.bruker.com/en/applications/microbiology-and-diagnostics/food-beverage-microbiology/ir-biotyper-for-food-microbiology.html">"IR Biotyper® for Food Microbiology"</a>. <i>www.bruker.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2024-03-20</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.bruker.com&rft.atitle=IR+Biotyper%C2%AE+for+Food+Microbiology&rft_id=https%3A%2F%2Fwww.bruker.com%2Fen%2Fapplications%2Fmicrobiology-and-diagnostics%2Ffood-beverage-microbiology%2Fir-biotyper-for-food-microbiology.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSilversteinWebsterKiemleBryce2016" class="citation book cs1">Silverstein, Robert M.; Webster, Francis X.; Kiemle, David J.; Bryce, David L. (2016). <i>Spectrometric Identification of Organic Compounds, 8th Edition</i>. Wiley. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-470-61637-6" title="Special:BookSources/978-0-470-61637-6"><bdi>978-0-470-61637-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Spectrometric+Identification+of+Organic+Compounds%2C+8th+Edition&rft.pub=Wiley&rft.date=2016&rft.isbn=978-0-470-61637-6&rft.aulast=Silverstein&rft.aufirst=Robert+M.&rft.au=Webster%2C+Francis+X.&rft.au=Kiemle%2C+David+J.&rft.au=Bryce%2C+David+L.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBanwell1966" class="citation book cs1">Banwell, Colin N. (1966). <i>Fundamentals of molecular spectroscopy</i>. European chemistry series. London: McGraw-Hill. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-07-094020-8" title="Special:BookSources/978-0-07-094020-8"><bdi>978-0-07-094020-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Fundamentals+of+molecular+spectroscopy&rft.place=London&rft.series=European+chemistry+series&rft.pub=McGraw-Hill&rft.date=1966&rft.isbn=978-0-07-094020-8&rft.aulast=Banwell&rft.aufirst=Colin+N.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAtkinsde_Paula2002" class="citation book cs1">Atkins P, de Paula J (2002). <i>Physical Chemistry</i> (7th ed.). New York: W.H.Freeman. p. 513. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-7167-3539-3" title="Special:BookSources/0-7167-3539-3"><bdi>0-7167-3539-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Physical+Chemistry&rft.place=New+York&rft.pages=513&rft.edition=7th&rft.pub=W.H.Freeman&rft.date=2002&rft.isbn=0-7167-3539-3&rft.aulast=Atkins&rft.aufirst=Peter&rft.au=de+Paula%2C+Julio&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span>|quote=the electric dipole moment of the molecule must change when the atoms are displaced relative to one another</span> </li> <li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAtkins1994" class="citation book cs1">Atkins, Peter (1994). <i>Physical Chemistry, 5th Edition</i>. Freeman. p. 577.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Physical+Chemistry%2C+5th+Edition&rft.pages=577&rft.pub=Freeman&rft.date=1994&rft.aulast=Atkins&rft.aufirst=Peter&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSchrader1995" class="citation book cs1">Schrader B (1995). <i>Infrared and Raman Spectroscopy: Methods and Applications</i>. New York: VCH, Weinheim. p. 787. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-527-26446-9" title="Special:BookSources/978-3-527-26446-9"><bdi>978-3-527-26446-9</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Infrared+and+Raman+Spectroscopy%3A+Methods+and+Applications&rft.place=New+York&rft.pages=787&rft.pub=VCH%2C+Weinheim&rft.date=1995&rft.isbn=978-3-527-26446-9&rft.aulast=Schrader&rft.aufirst=Bernhard&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFArnold_J._GordonRichard_A._Ford1972" class="citation book cs1">Arnold J. Gordon; Richard A. Ford (1972). <i>TheChemist's Companion</i>. Wiley. p. 179.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=TheChemist%27s+Companion&rft.pages=179&rft.pub=Wiley&rft.date=1972&rft.au=Arnold+J.+Gordon&rft.au=Richard+A.+Ford&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-Har-30"><span class="mw-cite-backlink">^ <a href="#cite_ref-Har_30-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Har_30-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHarwoodMoody1989" class="citation book cs1">Harwood LM, Moody CJ (1989). <a rel="nofollow" class="external text" href="https://archive.org/details/experimentalorga00harw/page/292"><i>Experimental organic chemistry: Principles and Practice</i></a> (Illustrated ed.). Wiley-Blackwell. p. <a rel="nofollow" class="external text" href="https://archive.org/details/experimentalorga00harw/page/292">292</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-632-02017-1" title="Special:BookSources/978-0-632-02017-1"><bdi>978-0-632-02017-1</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Experimental+organic+chemistry%3A+Principles+and+Practice&rft.pages=292&rft.edition=Illustrated&rft.pub=Wiley-Blackwell&rft.date=1989&rft.isbn=978-0-632-02017-1&rft.aulast=Harwood&rft.aufirst=Laurence+M.&rft.au=Moody%2C+Christopher+J.&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fexperimentalorga00harw%2Fpage%2F292&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFShadmanRoseYalin2016" class="citation journal cs1">Shadman S, Rose C, Yalin AP (2016). "Open-path cavity ring-down spectroscopy sensor for atmospheric ammonia". <i><a href="/wiki/Applied_Physics_B" title="Applied Physics B">Applied Physics B</a></i>. <b>122</b> (7): 194. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2016ApPhB.122..194S">2016ApPhB.122..194S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs00340-016-6461-5">10.1007/s00340-016-6461-5</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:123834102">123834102</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Applied+Physics+B&rft.atitle=Open-path+cavity+ring-down+spectroscopy+sensor+for+atmospheric+ammonia&rft.volume=122&rft.issue=7&rft.pages=194&rft.date=2016&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A123834102%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1007%2Fs00340-016-6461-5&rft_id=info%3Abibcode%2F2016ApPhB.122..194S&rft.aulast=Shadman&rft.aufirst=Soran&rft.au=Rose%2C+Charles&rft.au=Yalin%2C+Azer+P.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-white-32"><span class="mw-cite-backlink">^ <a href="#cite_ref-white_32-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-white_32-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=t2VSNnFoO3wC&pg=PA7"><i>Chromatography/Fourier transform infrared spectroscopy and its applications</i>, by Robert White, p7</a></span> </li> <li id="cite_note-wiley12-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-wiley12_33-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPollockKazarian2014" class="citation encyclopaedia cs1">Pollock, Hubert M; Kazarian, S G (2014). "Microspectroscopy in the Mid-Infrared". In Meyers, Robert A. (ed.). <i>Encyclopedia of Analytical Chemistry</i>. John Wiley & Sons Ltd. pp. 1–26. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2F9780470027318.a5609.pub2">10.1002/9780470027318.a5609.pub2</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780470027318" title="Special:BookSources/9780470027318"><bdi>9780470027318</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Microspectroscopy+in+the+Mid-Infrared&rft.btitle=Encyclopedia+of+Analytical+Chemistry&rft.pages=1-26&rft.pub=John+Wiley+%26+Sons+Ltd&rft.date=2014&rft_id=info%3Adoi%2F10.1002%2F9780470027318.a5609.pub2&rft.isbn=9780470027318&rft.aulast=Pollock&rft.aufirst=Hubert+M&rft.au=Kazarian%2C+S+G&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-34">^</a></b></span> <span class="reference-text">H M Pollock and D A Smith, The use of near-field probes for vibrational spectroscopy and photothermal imaging, in Handbook of vibrational spectroscopy, J.M. Chalmers and P.R. Griffiths (eds), John Wiley & Sons Ltd, Vol. 2, pp. 1472 - 1492 (2002)</span> </li> <li id="cite_note-:0-35"><span class="mw-cite-backlink">^ <a href="#cite_ref-:0_35-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-:0_35-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKrivanekLovejoyDellbyAoki2014" class="citation journal cs1">Krivanek OL, Lovejoy TC, Dellby N, Aoki T, Carpenter RW, Rez P, et al. (October 2014). "Vibrational spectroscopy in the electron microscope". <i>Nature</i>. <b>514</b> (7521): 209–12. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2014Natur.514..209K">2014Natur.514..209K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fnature13870">10.1038/nature13870</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/25297434">25297434</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:4467249">4467249</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Vibrational+spectroscopy+in+the+electron+microscope&rft.volume=514&rft.issue=7521&rft.pages=209-12&rft.date=2014-10&rft_id=info%3Adoi%2F10.1038%2Fnature13870&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4467249%23id-name%3DS2CID&rft_id=info%3Apmid%2F25297434&rft_id=info%3Abibcode%2F2014Natur.514..209K&rft.aulast=Krivanek&rft.aufirst=OL&rft.au=Lovejoy%2C+TC&rft.au=Dellby%2C+N&rft.au=Aoki%2C+T&rft.au=Carpenter%2C+RW&rft.au=Rez%2C+P&rft.au=Soignard%2C+E&rft.au=Zhu%2C+J&rft.au=Batson%2C+PE&rft.au=Lagos%2C+MJ&rft.au=Egerton%2C+RF&rft.au=Crozier%2C+PA&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFIdroboLupiniFengUnocic2018" class="citation journal cs1">Idrobo JC, Lupini AR, Feng T, Unocic RR, Walden FS, Gardiner DS, et al. (March 2018). <a rel="nofollow" class="external text" href="https://doi.org/10.1103%2FPhysRevLett.120.095901">"Temperature Measurement by a Nanoscale Electron Probe Using Energy Gain and Loss Spectroscopy"</a>. <i>Physical Review Letters</i>. <b>120</b> (9): 095901. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2018PhRvL.120i5901I">2018PhRvL.120i5901I</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1103%2FPhysRevLett.120.095901">10.1103/PhysRevLett.120.095901</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/29547334">29547334</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Physical+Review+Letters&rft.atitle=Temperature+Measurement+by+a+Nanoscale+Electron+Probe+Using+Energy+Gain+and+Loss+Spectroscopy&rft.volume=120&rft.issue=9&rft.pages=095901&rft.date=2018-03&rft_id=info%3Apmid%2F29547334&rft_id=info%3Adoi%2F10.1103%2FPhysRevLett.120.095901&rft_id=info%3Abibcode%2F2018PhRvL.120i5901I&rft.aulast=Idrobo&rft.aufirst=JC&rft.au=Lupini%2C+AR&rft.au=Feng%2C+T&rft.au=Unocic%2C+RR&rft.au=Walden%2C+FS&rft.au=Gardiner%2C+DS&rft.au=Lovejoy%2C+TC&rft.au=Dellby%2C+N&rft.au=Pantelides%2C+ST&rft.au=Krivanek%2C+OL&rft_id=https%3A%2F%2Fdoi.org%2F10.1103%252FPhysRevLett.120.095901&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLagosBatson2018" class="citation journal cs1">Lagos MJ, Batson PE (July 2018). "Thermometry with Subnanometer Resolution in the Electron Microscope Using the Principle of Detailed Balancing". <i>Nano Letters</i>. <b>18</b> (7): 4556–4563. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2018NanoL..18.4556L">2018NanoL..18.4556L</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Facs.nanolett.8b01791">10.1021/acs.nanolett.8b01791</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/29874456">29874456</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:206748146">206748146</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nano+Letters&rft.atitle=Thermometry+with+Subnanometer+Resolution+in+the+Electron+Microscope+Using+the+Principle+of+Detailed+Balancing&rft.volume=18&rft.issue=7&rft.pages=4556-4563&rft.date=2018-07&rft_id=info%3Adoi%2F10.1021%2Facs.nanolett.8b01791&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A206748146%23id-name%3DS2CID&rft_id=info%3Apmid%2F29874456&rft_id=info%3Abibcode%2F2018NanoL..18.4556L&rft.aulast=Lagos&rft.aufirst=MJ&rft.au=Batson%2C+PE&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-38">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHachtelHuangPopovsJansone-Popova2019" class="citation journal cs1">Hachtel JA, Huang J, Popovs I, Jansone-Popova S, Keum JK, Jakowski J, et al. (February 2019). <a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.aav5845">"Identification of site-specific isotopic labels by vibrational spectroscopy in the electron microscope"</a>. <i>Science</i>. <b>363</b> (6426): 525–528. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2019Sci...363..525H">2019Sci...363..525H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.aav5845">10.1126/science.aav5845</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30705191">30705191</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science&rft.atitle=Identification+of+site-specific+isotopic+labels+by+vibrational+spectroscopy+in+the+electron+microscope&rft.volume=363&rft.issue=6426&rft.pages=525-528&rft.date=2019-02&rft_id=info%3Apmid%2F30705191&rft_id=info%3Adoi%2F10.1126%2Fscience.aav5845&rft_id=info%3Abibcode%2F2019Sci...363..525H&rft.aulast=Hachtel&rft.aufirst=JA&rft.au=Huang%2C+J&rft.au=Popovs%2C+I&rft.au=Jansone-Popova%2C+S&rft.au=Keum%2C+JK&rft.au=Jakowski%2C+J&rft.au=Lovejoy%2C+TC&rft.au=Dellby%2C+N&rft.au=Krivanek%2C+OL&rft.au=Idrobo%2C+JC&rft_id=https%3A%2F%2Fdoi.org%2F10.1126%252Fscience.aav5845&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-39">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHageNichollsYatesMcCulloch2018" class="citation journal cs1">Hage FS, Nicholls RJ, Yates JR, McCulloch DG, Lovejoy TC, Dellby N, et al. (June 2018). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6018998">"Nanoscale momentum-resolved vibrational spectroscopy"</a>. <i>Science Advances</i>. <b>4</b> (6): eaar7495. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2018SciA....4.7495H">2018SciA....4.7495H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fsciadv.aar7495">10.1126/sciadv.aar7495</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6018998">6018998</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/29951584">29951584</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science+Advances&rft.atitle=Nanoscale+momentum-resolved+vibrational+spectroscopy&rft.volume=4&rft.issue=6&rft.pages=eaar7495&rft.date=2018-06&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC6018998%23id-name%3DPMC&rft_id=info%3Apmid%2F29951584&rft_id=info%3Adoi%2F10.1126%2Fsciadv.aar7495&rft_id=info%3Abibcode%2F2018SciA....4.7495H&rft.aulast=Hage&rft.aufirst=FS&rft.au=Nicholls%2C+RJ&rft.au=Yates%2C+JR&rft.au=McCulloch%2C+DG&rft.au=Lovejoy%2C+TC&rft.au=Dellby%2C+N&rft.au=Krivanek%2C+OL&rft.au=Refson%2C+K&rft.au=Ramasse%2C+QM&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC6018998&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-40">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSengaSuenagaBaroneMorishita2019" class="citation journal cs1">Senga R, Suenaga K, Barone P, Morishita S, Mauri F, Pichler T (September 2019). "Position and momentum mapping of vibrations in graphene nanostructures". <i>Nature</i>. <b>573</b> (7773): 247–250. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1812.08294">1812.08294</a></span>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2019Natur.573..247S">2019Natur.573..247S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs41586-019-1477-8">10.1038/s41586-019-1477-8</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/31406319">31406319</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:118999071">118999071</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Position+and+momentum+mapping+of+vibrations+in+graphene+nanostructures&rft.volume=573&rft.issue=7773&rft.pages=247-250&rft.date=2019-09&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A118999071%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2019Natur.573..247S&rft_id=info%3Aarxiv%2F1812.08294&rft_id=info%3Apmid%2F31406319&rft_id=info%3Adoi%2F10.1038%2Fs41586-019-1477-8&rft.aulast=Senga&rft.aufirst=R&rft.au=Suenaga%2C+K&rft.au=Barone%2C+P&rft.au=Morishita%2C+S&rft.au=Mauri%2C+F&rft.au=Pichler%2C+T&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLagosTrüglerHohenesterBatson2017" class="citation journal cs1">Lagos MJ, Trügler A, Hohenester U, Batson PE (March 2017). "Mapping vibrational surface and bulk modes in a single nanocube". <i>Nature</i>. <b>543</b> (7646): 529–532. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2017Natur.543..529L">2017Natur.543..529L</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fnature21699">10.1038/nature21699</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/28332537">28332537</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:4459728">4459728</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Mapping+vibrational+surface+and+bulk+modes+in+a+single+nanocube&rft.volume=543&rft.issue=7646&rft.pages=529-532&rft.date=2017-03&rft_id=info%3Adoi%2F10.1038%2Fnature21699&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4459728%23id-name%3DS2CID&rft_id=info%3Apmid%2F28332537&rft_id=info%3Abibcode%2F2017Natur.543..529L&rft.aulast=Lagos&rft.aufirst=MJ&rft.au=Tr%C3%BCgler%2C+A&rft.au=Hohenester%2C+U&rft.au=Batson%2C+PE&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGovyadinovKonečnáChuvilinVélez2017" class="citation journal cs1">Govyadinov AA, Konečná A, Chuvilin A, Vélez S, Dolado I, Nikitin AY, et al. (July 2017). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5522439">"Probing low-energy hyperbolic polaritons in van der Waals crystals with an electron microscope"</a>. <i>Nature Communications</i>. <b>8</b> (1): 95. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1611.05371">1611.05371</a></span>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2017NatCo...8...95G">2017NatCo...8...95G</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs41467-017-00056-y">10.1038/s41467-017-00056-y</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5522439">5522439</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/28733660">28733660</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature+Communications&rft.atitle=Probing+low-energy+hyperbolic+polaritons+in+van+der+Waals+crystals+with+an+electron+microscope&rft.volume=8&rft.issue=1&rft.pages=95&rft.date=2017-07&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC5522439%23id-name%3DPMC&rft_id=info%3Abibcode%2F2017NatCo...8...95G&rft_id=info%3Aarxiv%2F1611.05371&rft_id=info%3Apmid%2F28733660&rft_id=info%3Adoi%2F10.1038%2Fs41467-017-00056-y&rft.aulast=Govyadinov&rft.aufirst=AA&rft.au=Kone%C4%8Dn%C3%A1%2C+A&rft.au=Chuvilin%2C+A&rft.au=V%C3%A9lez%2C+S&rft.au=Dolado%2C+I&rft.au=Nikitin%2C+AY&rft.au=Lopatin%2C+S&rft.au=Casanova%2C+F&rft.au=Hueso%2C+LE&rft.au=Aizpurua%2C+J&rft.au=Hillenbrand%2C+R&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC5522439&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-43"><span class="mw-cite-backlink"><b><a href="#cite_ref-43">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFVenkatramanLevinMarchRez2019" class="citation journal cs1">Venkatraman K, Levin BD, March K, Rez P, Crozier PA (2019). "Vibrational spectroscopy at atomic resolution with electron impact scattering". <i>Nature Physics</i>. <b>15</b> (12): 1237–1241. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1812.08895">1812.08895</a></span>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2019NatPh..15.1237V">2019NatPh..15.1237V</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs41567-019-0675-5">10.1038/s41567-019-0675-5</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119452520">119452520</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature+Physics&rft.atitle=Vibrational+spectroscopy+at+atomic+resolution+with+electron+impact+scattering&rft.volume=15&rft.issue=12&rft.pages=1237-1241&rft.date=2019&rft_id=info%3Aarxiv%2F1812.08895&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A119452520%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2Fs41567-019-0675-5&rft_id=info%3Abibcode%2F2019NatPh..15.1237V&rft.aulast=Venkatraman&rft.aufirst=K&rft.au=Levin%2C+BD&rft.au=March%2C+K&rft.au=Rez%2C+P&rft.au=Crozier%2C+PA&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-44">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHenschelAnderssonJespersMehdi_Ghahremanpour2020" class="citation journal cs1">Henschel H, Andersson AT, Jespers W, Mehdi Ghahremanpour M, van der Spoel D (May 2020). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7304875">"Theoretical Infrared Spectra: Quantitative Similarity Measures and Force Fields"</a>. <i>Journal of Chemical Theory and Computation</i>. <b>16</b> (5): 3307–3315. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Facs.jctc.0c00126">10.1021/acs.jctc.0c00126</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7304875">7304875</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/32271575">32271575</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Chemical+Theory+and+Computation&rft.atitle=Theoretical+Infrared+Spectra%3A+Quantitative+Similarity+Measures+and+Force+Fields&rft.volume=16&rft.issue=5&rft.pages=3307-3315&rft.date=2020-05&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC7304875%23id-name%3DPMC&rft_id=info%3Apmid%2F32271575&rft_id=info%3Adoi%2F10.1021%2Facs.jctc.0c00126&rft.aulast=Henschel&rft.aufirst=H&rft.au=Andersson%2C+AT&rft.au=Jespers%2C+W&rft.au=Mehdi+Ghahremanpour%2C+M&rft.au=van+der+Spoel%2C+D&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC7304875&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-OChemSmith3E-45"><span class="mw-cite-backlink">^ <a href="#cite_ref-OChemSmith3E_45-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-OChemSmith3E_45-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-OChemSmith3E_45-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmith2011" class="citation book cs1">Smith JG (2011). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20180628152511/http://highered.mheducation.com/sites/007340277x/student_view0/index.html">"Chapter 13 Mass Spectrometry and Infrared Spectroscopy"</a>. In Hodge T, Nemmers D, Klein J (eds.). <i>Organic chemistry</i> (3rd ed.). New York, NY: McGraw-Hill. pp. 463–488. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-07-337562-5" title="Special:BookSources/978-0-07-337562-5"><bdi>978-0-07-337562-5</bdi></a>. Archived from <a rel="nofollow" class="external text" href="http://highered.mheducation.com/sites/007340277x/student_view0/index.html">the original</a> <span class="cs1-format">(Book)</span> on 2018-06-28<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-06-30</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Chapter+13+Mass+Spectrometry+and+Infrared+Spectroscopy&rft.btitle=Organic+chemistry&rft.place=New+York%2C+NY&rft.pages=463-488&rft.edition=3rd&rft.pub=McGraw-Hill&rft.date=2011&rft.isbn=978-0-07-337562-5&rft.aulast=Smith&rft.aufirst=Janice+Gorzynski&rft_id=http%3A%2F%2Fhighered.mheducation.com%2Fsites%2F007340277x%2Fstudent_view0%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-46"><span class="mw-cite-backlink"><b><a href="#cite_ref-46">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBadger1934" class="citation journal cs1">Badger R (1934). <a rel="nofollow" class="external text" href="https://authors.library.caltech.edu/10440/1/BADjcp34.pdf">"A Relation Between Internuclear Distances and Bond Force Constants"</a> <span class="cs1-format">(PDF)</span>. <i>The Journal of Chemical Physics</i>. <b>2</b> (3): 128. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1934JChPh...2..128B">1934JChPh...2..128B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1063%2F1.1749433">10.1063/1.1749433</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Journal+of+Chemical+Physics&rft.atitle=A+Relation+Between+Internuclear+Distances+and+Bond+Force+Constants&rft.volume=2&rft.issue=3&rft.pages=128&rft.date=1934&rft_id=info%3Adoi%2F10.1063%2F1.1749433&rft_id=info%3Abibcode%2F1934JChPh...2..128B&rft.aulast=Badger&rft.aufirst=R&rft_id=https%3A%2F%2Fauthors.library.caltech.edu%2F10440%2F1%2FBADjcp34.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-47"><span class="mw-cite-backlink"><b><a href="#cite_ref-47">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKohliDaviesVinhWest2006" class="citation journal cs1">Kohli KK, Davies G, Vinh NQ, West D, Estreicher SK, Gregorkiewicz T, et al. (June 2006). "Isotope dependence of the lifetime of the vibration of oxygen in silicon". <i>Physical Review Letters</i>. <b>96</b> (22): 225503. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2006PhRvL..96v5503K">2006PhRvL..96v5503K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1103%2FPhysRevLett.96.225503">10.1103/PhysRevLett.96.225503</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/16803320">16803320</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Physical+Review+Letters&rft.atitle=Isotope+dependence+of+the+lifetime+of+the+vibration+of+oxygen+in+silicon&rft.volume=96&rft.issue=22&rft.pages=225503&rft.date=2006-06&rft_id=info%3Apmid%2F16803320&rft_id=info%3Adoi%2F10.1103%2FPhysRevLett.96.225503&rft_id=info%3Abibcode%2F2006PhRvL..96v5503K&rft.aulast=Kohli&rft.aufirst=KK&rft.au=Davies%2C+G&rft.au=Vinh%2C+NQ&rft.au=West%2C+D&rft.au=Estreicher%2C+SK&rft.au=Gregorkiewicz%2C+T&rft.au=Izeddin%2C+I&rft.au=Itoh%2C+KM&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-48">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHammLimHochstrasser1998" class="citation journal cs1">Hamm P, Lim MH, Hochstrasser RM (1998). "Structure of the amide I band of peptides measured by femtosecond nonlinear-infrared spectroscopy". <i>J. Phys. Chem. B</i>. <b>102</b> (31): 6123–6138. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fjp9813286">10.1021/jp9813286</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=J.+Phys.+Chem.+B&rft.atitle=Structure+of+the+amide+I+band+of+peptides+measured+by+femtosecond+nonlinear-infrared+spectroscopy&rft.volume=102&rft.issue=31&rft.pages=6123-6138&rft.date=1998&rft_id=info%3Adoi%2F10.1021%2Fjp9813286&rft.aulast=Hamm&rft.aufirst=P&rft.au=Lim%2C+MH&rft.au=Hochstrasser%2C+RM&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-49">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMukamel2000" class="citation journal cs1">Mukamel S (2000). "Multidimensional femtosecond correlation spectroscopies of electronic and vibrational excitations". <i>Annual Review of Physical Chemistry</i>. <b>51</b> (1): 691–729. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2000ARPC...51..691M">2000ARPC...51..691M</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1146%2Fannurev.physchem.51.1.691">10.1146/annurev.physchem.51.1.691</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/11031297">11031297</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:31230696">31230696</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annual+Review+of+Physical+Chemistry&rft.atitle=Multidimensional+femtosecond+correlation+spectroscopies+of+electronic+and+vibrational+excitations&rft.volume=51&rft.issue=1&rft.pages=691-729&rft.date=2000&rft_id=info%3Adoi%2F10.1146%2Fannurev.physchem.51.1.691&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A31230696%23id-name%3DS2CID&rft_id=info%3Apmid%2F11031297&rft_id=info%3Abibcode%2F2000ARPC...51..691M&rft.aulast=Mukamel&rft.aufirst=S&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> <li id="cite_note-50"><span class="mw-cite-backlink"><b><a href="#cite_ref-50">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDemirdövenCheatumChungKhalil2004" class="citation journal cs1">Demirdöven N, Cheatum CM, Chung HS, Khalil M, Knoester J, Tokmakoff A (June 2004). <a rel="nofollow" class="external text" href="https://pure.rug.nl/ws/files/6680272/2004JAmChemSocDemirdoven.pdf">"Two-dimensional infrared spectroscopy of antiparallel beta-sheet secondary structure"</a> <span class="cs1-format">(PDF)</span>. <i>Journal of the American Chemical Society</i>. <b>126</b> (25): 7981–90. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fja049811j">10.1021/ja049811j</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/15212548">15212548</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+the+American+Chemical+Society&rft.atitle=Two-dimensional+infrared+spectroscopy+of+antiparallel+beta-sheet+secondary+structure&rft.volume=126&rft.issue=25&rft.pages=7981-90&rft.date=2004-06&rft_id=info%3Adoi%2F10.1021%2Fja049811j&rft_id=info%3Apmid%2F15212548&rft.aulast=Demird%C3%B6ven&rft.aufirst=N&rft.au=Cheatum%2C+CM&rft.au=Chung%2C+HS&rft.au=Khalil%2C+M&rft.au=Knoester%2C+J&rft.au=Tokmakoff%2C+A&rft_id=https%3A%2F%2Fpure.rug.nl%2Fws%2Ffiles%2F6680272%2F2004JAmChemSocDemirdoven.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AInfrared+spectroscopy" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Infrared_spectroscopy&action=edit&section=21" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Infrared_spectroscopy" class="extiw" title="commons:Category:Infrared spectroscopy">Infrared spectroscopy</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110904091402/http://www2.dq.fct.unl.pt/qoa/jas/ir.html">Infrared spectroscopy for organic chemists</a></li> <li><a rel="nofollow" class="external text" href="http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng">Organic compounds spectrum database</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20130114222220/http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng">Archived</a> 2013-01-14 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Branches_of_chemistry" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Branches_of_chemistry" title="Template:Branches of chemistry"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Branches_of_chemistry" title="Template talk:Branches of chemistry"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Branches_of_chemistry" title="Special:EditPage/Template:Branches of chemistry"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Branches_of_chemistry" style="font-size:114%;margin:0 4em">Branches of <a href="/wiki/Chemistry" title="Chemistry">chemistry</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><a href="/wiki/Glossary_of_chemical_formulae" title="Glossary of chemical formulae">Glossary of chemical formulae</a></li> <li><a href="/wiki/List_of_biomolecules" title="List of biomolecules">List of biomolecules</a></li> <li><a href="/wiki/List_of_inorganic_compounds" title="List of inorganic compounds">List of inorganic compounds</a></li> <li><a href="/wiki/Periodic_table" title="Periodic table">Periodic table</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Analytical_chemistry" title="Analytical chemistry">Analytical</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Instrumental_chemistry" title="Instrumental chemistry">Instrumental chemistry</a></li> <li><a href="/wiki/Electroanalytical_methods" title="Electroanalytical methods">Electroanalytical methods</a></li> <li><a href="/wiki/Spectroscopy" title="Spectroscopy">Spectroscopy</a> <ul><li><a class="mw-selflink selflink">IR</a></li> <li><a href="/wiki/Raman_spectroscopy" title="Raman spectroscopy">Raman</a></li> <li><a href="/wiki/Ultraviolet%E2%80%93visible_spectroscopy" title="Ultraviolet–visible spectroscopy">UV-Vis</a></li> <li><a href="/wiki/Nuclear_magnetic_resonance_spectroscopy" title="Nuclear magnetic resonance spectroscopy">NMR</a></li></ul></li> <li><a href="/wiki/Mass_spectrometry" title="Mass spectrometry">Mass spectrometry</a> <ul><li><a href="/wiki/Electron_ionization" title="Electron ionization">EI</a></li> <li><a href="/wiki/Inductively_coupled_plasma_mass_spectrometry" title="Inductively coupled plasma mass spectrometry">ICP</a></li> <li><a href="/wiki/Matrix-assisted_laser_desorption/ionization" title="Matrix-assisted laser desorption/ionization">MALDI</a></li></ul></li> <li><a href="/wiki/Separation_process" title="Separation process">Separation process</a></li> <li><a href="/wiki/Chromatography" title="Chromatography">Chromatography</a> <ul><li><a href="/wiki/Gas_chromatography" title="Gas chromatography">GC</a></li> <li><a href="/wiki/High-performance_liquid_chromatography" title="High-performance liquid chromatography">HPLC</a></li></ul></li> <li><a href="/wiki/Crystallography" title="Crystallography">Crystallography</a></li> <li><a href="/wiki/Characterization_(materials_science)" title="Characterization (materials science)">Characterization</a></li> <li><a href="/wiki/Titration" title="Titration">Titration</a></li> <li><a href="/wiki/Wet_chemistry" title="Wet chemistry">Wet chemistry</a></li> <li><a href="/wiki/Calorimetry" title="Calorimetry">Calorimetry</a></li> <li><a href="/wiki/Elemental_analysis" title="Elemental analysis">Elemental analysis</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Theoretical_chemistry" title="Theoretical chemistry">Theoretical</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Quantum_chemistry" title="Quantum chemistry">Quantum chemistry</a></li> <li><a href="/wiki/Computational_chemistry" title="Computational chemistry">Computational chemistry</a> <ul><li><a href="/wiki/Mathematical_chemistry" title="Mathematical chemistry">Mathematical chemistry</a></li></ul></li> <li><a href="/wiki/Molecular_modelling" title="Molecular modelling">Molecular modelling</a></li> <li><a href="/wiki/Molecular_mechanics" title="Molecular mechanics">Molecular mechanics</a></li> <li><a href="/wiki/Molecular_dynamics" title="Molecular dynamics">Molecular dynamics</a></li> <li><a href="/wiki/Molecular_geometry" title="Molecular geometry">Molecular geometry</a> <ul><li><a href="/wiki/VSEPR_theory" title="VSEPR theory">VSEPR theory</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Physical_chemistry" title="Physical chemistry">Physical</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Electrochemistry" title="Electrochemistry">Electrochemistry</a> <ul><li><a href="/wiki/Spectroelectrochemistry" title="Spectroelectrochemistry">Spectroelectrochemistry</a></li> <li><a href="/wiki/Photoelectrochemistry" title="Photoelectrochemistry">Photoelectrochemistry</a></li></ul></li> <li><a href="/wiki/Thermochemistry" title="Thermochemistry">Thermochemistry</a></li> <li><a href="/wiki/Chemical_thermodynamics" title="Chemical thermodynamics">Chemical thermodynamics</a></li> <li><a href="/wiki/Surface_science" title="Surface science">Surface science</a></li> <li><a href="/wiki/Interface_and_colloid_science" title="Interface and colloid science">Interface and colloid science</a> <ul><li><a href="/wiki/Micromeritics" title="Micromeritics">Micromeritics</a></li></ul></li> <li><a href="/wiki/Cryochemistry" title="Cryochemistry">Cryochemistry</a></li> <li><a href="/wiki/Sonochemistry" title="Sonochemistry">Sonochemistry</a></li> <li><a href="/wiki/Structural_chemistry" title="Structural chemistry">Structural chemistry</a></li> <li><a href="/wiki/Chemical_physics" title="Chemical physics">Chemical physics</a> <ul><li><a href="/wiki/Molecular_physics" title="Molecular physics">Molecular physics</a></li></ul></li> <li><a href="/wiki/Femtochemistry" title="Femtochemistry">Femtochemistry</a></li> <li><a href="/wiki/Chemical_kinetics" title="Chemical kinetics">Chemical kinetics</a></li> <li><a href="/wiki/Spectroscopy" title="Spectroscopy">Spectroscopy</a></li> <li><a href="/wiki/Photochemistry" title="Photochemistry">Photochemistry</a></li> <li><a href="/wiki/Spin_chemistry" title="Spin chemistry">Spin chemistry</a></li> <li><a href="/wiki/Microwave_chemistry" title="Microwave chemistry">Microwave chemistry</a></li> <li><a href="/wiki/Equilibrium_chemistry" title="Equilibrium chemistry">Equilibrium chemistry</a></li> <li><a href="/wiki/Mechanochemistry" title="Mechanochemistry">Mechanochemistry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Inorganic_chemistry" title="Inorganic chemistry">Inorganic</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Coordination_complex" title="Coordination complex">Coordination chemistry</a></li> <li><a href="/wiki/Magnetochemistry" title="Magnetochemistry">Magnetochemistry</a></li> <li><a href="/wiki/Organometallic_chemistry" title="Organometallic chemistry">Organometallic chemistry</a> <ul><li><a href="/wiki/Organolanthanide_chemistry" title="Organolanthanide chemistry">Organolanthanide chemistry</a></li></ul></li> <li><a href="/wiki/Atom_cluster" class="mw-redirect" title="Atom cluster">Cluster chemistry</a></li> <li><a href="/wiki/Solid-state_chemistry" title="Solid-state chemistry">Solid-state chemistry</a></li> <li><a href="/wiki/Ceramic_chemistry" class="mw-redirect" title="Ceramic chemistry">Ceramic chemistry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Organic_chemistry" title="Organic chemistry">Organic</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Stereochemistry" title="Stereochemistry">Stereochemistry</a> <ul><li><a href="/wiki/Alkane_stereochemistry" class="mw-redirect" title="Alkane stereochemistry">Alkane stereochemistry</a></li></ul></li> <li><a href="/wiki/Physical_organic_chemistry" title="Physical organic chemistry">Physical organic chemistry</a></li> <li><a href="/wiki/Organic_reactions" class="mw-redirect" title="Organic reactions">Organic reactions</a></li> <li><a href="/wiki/Organic_synthesis" title="Organic synthesis">Organic synthesis</a></li> <li><a href="/wiki/Retrosynthetic_analysis" title="Retrosynthetic analysis">Retrosynthetic analysis</a></li> <li><a href="/wiki/Enantioselective_synthesis" title="Enantioselective synthesis">Enantioselective synthesis</a></li> <li><a href="/wiki/Total_synthesis" title="Total synthesis">Total synthesis</a> / <a href="/wiki/Semisynthesis" title="Semisynthesis">Semisynthesis</a></li> <li><a href="/wiki/Fullerene_chemistry" title="Fullerene chemistry">Fullerene chemistry</a></li> <li><a href="/wiki/Polymer_chemistry" title="Polymer chemistry">Polymer chemistry</a></li> <li><a href="/wiki/Petrochemistry" class="mw-redirect" title="Petrochemistry">Petrochemistry</a></li> <li><a href="/wiki/Dynamic_covalent_chemistry" title="Dynamic covalent chemistry">Dynamic covalent chemistry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Biochemistry" title="Biochemistry">Biological</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Biochemistry" title="Biochemistry">Biochemistry</a> <ul><li><a href="/wiki/Molecular_biology" title="Molecular biology">Molecular biology</a></li> <li><a href="/wiki/Cell_biology" title="Cell biology">Cell biology</a></li></ul></li> <li><a href="/wiki/Chemical_biology" title="Chemical biology">Chemical biology</a> <ul><li><a href="/wiki/Bioorthogonal_chemistry" title="Bioorthogonal chemistry">Bioorthogonal chemistry</a></li></ul></li> <li><a href="/wiki/Medicinal_chemistry" title="Medicinal chemistry">Medicinal chemistry</a> <ul><li><a href="/wiki/Pharmacology" title="Pharmacology">Pharmacology</a></li></ul></li> <li><a href="/wiki/Clinical_chemistry" title="Clinical chemistry">Clinical chemistry</a></li> <li><a href="/wiki/Neurochemistry" title="Neurochemistry">Neurochemistry</a></li> <li><a href="/wiki/Bioorganic_chemistry" title="Bioorganic chemistry">Bioorganic chemistry</a></li> <li><a href="/wiki/Bioorganometallic_chemistry" title="Bioorganometallic chemistry">Bioorganometallic chemistry</a></li> <li><a href="/wiki/Bioinorganic_chemistry" title="Bioinorganic chemistry">Bioinorganic chemistry</a></li> <li><a href="/wiki/Biophysical_chemistry" title="Biophysical chemistry">Biophysical chemistry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Interdisciplinarity" title="Interdisciplinarity">Interdisciplinarity</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Nuclear_chemistry" title="Nuclear chemistry">Nuclear chemistry</a> <ul><li><a href="/wiki/Radiochemistry" title="Radiochemistry">Radiochemistry</a></li> <li><a href="/wiki/Radiation_chemistry" title="Radiation chemistry">Radiation chemistry</a></li> <li><a href="/wiki/Actinide_chemistry" title="Actinide chemistry">Actinide chemistry</a></li></ul></li> <li><a href="/wiki/Cosmochemistry" title="Cosmochemistry">Cosmochemistry</a> / <a href="/wiki/Astrochemistry" title="Astrochemistry">Astrochemistry</a> / <a href="/wiki/Stellar_chemistry" title="Stellar chemistry">Stellar chemistry</a></li> <li><a href="/wiki/Geochemistry" title="Geochemistry">Geochemistry</a> <ul><li><a href="/wiki/Biogeochemistry" title="Biogeochemistry">Biogeochemistry</a></li> <li><a href="/wiki/Photogeochemistry" title="Photogeochemistry">Photogeochemistry</a></li></ul></li></ul> <ul><li><a href="/wiki/Environmental_chemistry" title="Environmental chemistry">Environmental chemistry</a> <ul><li><a href="/wiki/Atmospheric_chemistry" title="Atmospheric chemistry">Atmospheric chemistry</a></li> <li><a href="/wiki/Ocean_chemistry" class="mw-redirect" title="Ocean chemistry">Ocean chemistry</a></li></ul></li> <li><a href="/wiki/Clay_chemistry" title="Clay chemistry">Clay chemistry</a></li> <li><a href="/wiki/Carbochemistry" title="Carbochemistry">Carbochemistry</a></li> <li><a href="/wiki/Food_chemistry" title="Food chemistry">Food chemistry</a> <ul><li><a href="/wiki/Carbohydrate_chemistry" class="mw-redirect" title="Carbohydrate chemistry">Carbohydrate chemistry</a></li> <li><a href="/wiki/Food_physical_chemistry" title="Food physical chemistry">Food physical chemistry</a></li></ul></li> <li><a href="/wiki/Agricultural_chemistry" title="Agricultural chemistry">Agricultural chemistry</a> <ul><li><a href="/wiki/Soil_chemistry" title="Soil chemistry">Soil chemistry</a></li></ul></li></ul> <ul><li><a href="/wiki/Chemistry_education" title="Chemistry education">Chemistry education</a> <ul><li><a href="/wiki/Amateur_chemistry" title="Amateur chemistry">Amateur chemistry</a></li> <li><a href="/wiki/General_chemistry" title="General chemistry">General chemistry</a></li></ul></li> <li><a href="/wiki/Clandestine_chemistry" title="Clandestine chemistry">Clandestine chemistry</a></li> <li><a href="/wiki/Forensic_chemistry" title="Forensic chemistry">Forensic chemistry</a> <ul><li><a href="/wiki/Forensic_toxicology" title="Forensic toxicology">Forensic toxicology</a></li> <li><a href="/wiki/Post-mortem_chemistry" title="Post-mortem chemistry">Post-mortem chemistry</a></li></ul></li></ul> <ul><li><a href="/wiki/Nanochemistry" title="Nanochemistry">Nanochemistry</a> <ul><li><a href="/wiki/Supramolecular_chemistry" title="Supramolecular chemistry">Supramolecular chemistry</a></li></ul></li> <li><a href="/wiki/Chemical_synthesis" title="Chemical synthesis">Chemical synthesis</a> <ul><li><a href="/wiki/Green_chemistry" title="Green chemistry">Green chemistry</a></li> <li><a href="/wiki/Click_chemistry" title="Click chemistry">Click chemistry</a></li> <li><a href="/wiki/Combinatorial_chemistry" title="Combinatorial chemistry">Combinatorial chemistry</a></li> <li><a href="/wiki/Biosynthesis" title="Biosynthesis">Biosynthesis</a></li></ul></li> <li><a href="/wiki/Chemical_engineering" title="Chemical engineering">Chemical engineering</a> <ul><li><a href="/wiki/Stoichiometry" title="Stoichiometry">Stoichiometry</a></li></ul></li> <li><a href="/wiki/Materials_science" title="Materials science">Materials science</a> <ul><li><a href="/wiki/Metallurgy" title="Metallurgy">Metallurgy</a></li> <li><a href="/wiki/Ceramic_engineering" title="Ceramic engineering">Ceramic engineering</a></li> <li><a href="/wiki/Polymer_science" title="Polymer science">Polymer science</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">See also</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_chemistry" title="History of chemistry">History of chemistry</a></li> <li><a href="/wiki/Nobel_Prize_in_Chemistry" title="Nobel Prize in Chemistry">Nobel Prize in Chemistry</a></li> <li><a href="/wiki/Timeline_of_chemistry" title="Timeline of chemistry">Timeline of chemistry</a> <ul><li><a href="/wiki/Discovery_of_chemical_elements" title="Discovery of chemical elements">of element discoveries</a></li></ul></li> <li>"<a href="/wiki/The_central_science" title="The central science">The central science</a>"</li> <li><a href="/wiki/Chemical_reaction" title="Chemical reaction">Chemical reaction</a> <ul><li><a href="/wiki/Catalysis" title="Catalysis">Catalysis</a></li></ul></li> <li><a href="/wiki/Chemical_element" title="Chemical element">Chemical element</a></li> <li><a href="/wiki/Chemical_compound" title="Chemical compound">Chemical compound</a></li> <li><a href="/wiki/Atom" title="Atom">Atom</a></li> <li><a href="/wiki/Molecule" title="Molecule">Molecule</a></li> <li><a href="/wiki/Ion" title="Ion">Ion</a></li> <li><a href="/wiki/Chemical_substance" title="Chemical substance">Chemical substance</a></li> <li><a href="/wiki/Chemical_bond" title="Chemical bond">Chemical bond</a></li> <li><a href="/wiki/Alchemy" title="Alchemy">Alchemy</a></li> <li><a href="/wiki/Quantum_mechanics" title="Quantum mechanics">Quantum mechanics</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Chemistry" title="Category:Chemistry">Category</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <b><a href="https://commons.wikimedia.org/wiki/Category:Chemistry" class="extiw" title="commons:Category:Chemistry">Commons</a></b></li> <li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Symbol_portal_class.svg" class="mw-file-description" title="Portal"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/16px-Symbol_portal_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/23px-Symbol_portal_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/31px-Symbol_portal_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span> <b><a href="/wiki/Portal:Chemistry" title="Portal:Chemistry">Portal</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="WikiProject"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/16px-People_icon.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/24px-People_icon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/32px-People_icon.svg.png 2x" data-file-width="100" data-file-height="100" /></span></span> <b><a href="/wiki/Wikipedia:WikiProject_Chemistry" title="Wikipedia:WikiProject Chemistry">WikiProject</a></b></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Analytical_chemistry" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Analytical_chemistry" title="Template:Analytical chemistry"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Analytical_chemistry" title="Template talk:Analytical chemistry"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Analytical_chemistry" title="Special:EditPage/Template:Analytical chemistry"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Analytical_chemistry" style="font-size:114%;margin:0 4em"><a href="/wiki/Analytical_chemistry" title="Analytical chemistry">Analytical chemistry</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Measuring_instrument" class="mw-redirect" title="Measuring instrument">Instrumentation</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Atomic_absorption_spectroscopy" title="Atomic absorption spectroscopy">Atomic absorption spectrometer</a></li> <li><a href="/wiki/Flame_emission_spectroscopy" class="mw-redirect" title="Flame emission spectroscopy">Flame emission spectrometer</a></li> <li><a href="/wiki/Gas_chromatography" title="Gas chromatography">Gas chromatograph</a></li> <li><a href="/wiki/High-performance_liquid_chromatography" title="High-performance liquid chromatography">High-performance liquid chromatograph</a></li> <li><a class="mw-selflink selflink">Infrared spectrometer</a></li> <li><a href="/wiki/Mass_spectrometry" title="Mass spectrometry">Mass spectrometer</a></li> <li><a href="/wiki/Melting_point_apparatus" class="mw-redirect" title="Melting point apparatus">Melting point apparatus</a></li> <li><a href="/wiki/Microscope" title="Microscope">Microscope</a></li> <li><a href="/wiki/Optical_spectrometer" title="Optical spectrometer">Optical spectrometer</a></li> <li><a href="/wiki/Spectrophotometry" title="Spectrophotometry">Spectrophotometer</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Techniques</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Calorimetry" title="Calorimetry">Calorimetry</a></li> <li><a href="/wiki/Chromatography" title="Chromatography">Chromatography</a></li> <li><a href="/wiki/Electroanalytical_methods" title="Electroanalytical methods">Electroanalytical methods</a></li> <li><a href="/wiki/Gravimetric_analysis" title="Gravimetric analysis">Gravimetric analysis</a></li> <li><a href="/wiki/Ion_mobility_spectrometry" title="Ion mobility spectrometry">Ion mobility spectrometry</a></li> <li><a href="/wiki/Mass_spectrometry" title="Mass spectrometry">Mass spectrometry</a></li> <li><a href="/wiki/Spectroscopy" title="Spectroscopy">Spectroscopy</a></li> <li><a href="/wiki/Titration" title="Titration">Titration</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Sampling</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Sub-sampling_(chemistry)#Coning_and_quartering" title="Sub-sampling (chemistry)">Coning and quartering</a></li> <li><a href="/wiki/Dilution_(equation)" title="Dilution (equation)">Dilution</a></li> <li><a href="/wiki/Dissolution_(chemistry)" class="mw-redirect" title="Dissolution (chemistry)">Dissolution</a></li> <li><a href="/wiki/Filtration" title="Filtration">Filtration</a></li> <li><a href="/wiki/Masking_agent" title="Masking agent">Masking</a></li> <li><a href="/wiki/Powder_(substance)" class="mw-redirect" title="Powder (substance)">Pulverization</a></li> <li><a href="/wiki/Sample_preparation" title="Sample preparation">Sample preparation</a></li> <li><a href="/wiki/Separation_process" title="Separation process">Separation process</a></li> <li><a href="/wiki/Sub-sampling_(chemistry)" title="Sub-sampling (chemistry)">Sub-sampling</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Calibration</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chemometrics" title="Chemometrics">Chemometrics</a></li> <li><a href="/wiki/Calibration_curve" title="Calibration curve">Calibration curve</a></li> <li><a href="/wiki/Matrix_(chemical_analysis)" title="Matrix (chemical analysis)">Matrix effect</a></li> <li><a href="/wiki/Internal_standard" title="Internal standard">Internal standard</a></li> <li><a href="/wiki/Standard_addition" title="Standard addition">Standard addition</a></li> <li><a href="/wiki/Isotope_dilution" title="Isotope dilution">Isotope dilution</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Prominent <a href="/wiki/List_of_important_publications_in_chemistry#Analytical_chemistry" title="List of important publications in chemistry">publications</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/Analyst_(journal)" title="Analyst (journal)">Analyst</a></i></li> <li><i><a href="/wiki/Analytica_Chimica_Acta" title="Analytica Chimica Acta">Analytica Chimica Acta</a></i></li> <li><i><a href="/wiki/Analytical_and_Bioanalytical_Chemistry" title="Analytical and Bioanalytical Chemistry">Analytical and Bioanalytical Chemistry</a></i></li> <li><i><a href="/wiki/Analytical_Chemistry_(journal)" title="Analytical Chemistry (journal)">Analytical Chemistry</a></i></li> <li><i><a href="/wiki/Analytical_Biochemistry" title="Analytical Biochemistry">Analytical Biochemistry</a></i></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Analytical_chemistry" title="Category:Analytical chemistry">Category</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <b><a href="https://commons.wikimedia.org/wiki/Category:Analytical_chemistry" class="extiw" title="commons:Category:Analytical chemistry">Commons</a></b></li> <li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Symbol_portal_class.svg" class="mw-file-description" title="Portal"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/16px-Symbol_portal_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/23px-Symbol_portal_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/e/e2/Symbol_portal_class.svg/31px-Symbol_portal_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span><b><a href="/wiki/Portal:Chemistry" title="Portal:Chemistry">Portal</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="WikiProject"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/16px-People_icon.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/24px-People_icon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/32px-People_icon.svg.png 2x" data-file-width="100" data-file-height="100" /></span></span> <b><a href="/wiki/Wikipedia:WikiProject_Chemistry" title="Wikipedia:WikiProject Chemistry">WikiProject</a></b></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Spectroscopy" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Branches_of_spectroscopy" title="Template:Branches of spectroscopy"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Branches_of_spectroscopy" title="Template talk:Branches of spectroscopy"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Branches_of_spectroscopy" title="Special:EditPage/Template:Branches of spectroscopy"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Spectroscopy" style="font-size:114%;margin:0 4em"><a href="/wiki/Spectroscopy" title="Spectroscopy">Spectroscopy</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a class="mw-selflink selflink">Vibrational (IR)</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fourier-transform_infrared_spectroscopy" title="Fourier-transform infrared spectroscopy">FT-IR</a></li> <li><a href="/wiki/Raman_spectroscopy" title="Raman spectroscopy">Raman</a></li> <li><a href="/wiki/Resonance_Raman_spectroscopy" title="Resonance Raman spectroscopy">Resonance Raman</a></li> <li><a href="/wiki/Rotational_spectroscopy" title="Rotational spectroscopy">Rotational</a></li> <li><a href="/wiki/Rotational%E2%80%93vibrational_spectroscopy" title="Rotational–vibrational spectroscopy">Rotational–vibrational</a></li> <li><a href="/wiki/Molecular_vibration" title="Molecular vibration">Vibrational</a></li> <li><a href="/wiki/Vibrational_circular_dichroism" title="Vibrational circular dichroism">Vibrational circular dichroism</a></li> <li><a href="/wiki/Nuclear_resonance_vibrational_spectroscopy" title="Nuclear resonance vibrational spectroscopy">Nuclear resonance vibrational spectroscopy</a></li> <li><a href="/wiki/Vibrational_spectroscopy_of_linear_molecules" title="Vibrational spectroscopy of linear molecules">Vibrational spectroscopy of linear molecules</a></li> <li><a href="/wiki/Thermal_infrared_spectroscopy" title="Thermal infrared spectroscopy">Thermal infrared spectroscopy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">UV–Vis–NIR "Optical"</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ultraviolet%E2%80%93visible_spectroscopy" title="Ultraviolet–visible spectroscopy">Ultraviolet–visible</a></li> <li><a href="/wiki/Fluorescence_spectroscopy" title="Fluorescence spectroscopy">Fluorescence</a> <ul><li><a href="/wiki/Cold_vapour_atomic_fluorescence_spectroscopy" title="Cold vapour atomic fluorescence spectroscopy">Cold vapour atomic</a></li></ul></li> <li><a href="/wiki/Vibronic_spectroscopy" title="Vibronic spectroscopy">Vibronic</a></li> <li><a href="/wiki/Near-infrared_spectroscopy" title="Near-infrared spectroscopy">Near-infrared</a></li> <li><a href="/wiki/Resonance-enhanced_multiphoton_ionization" title="Resonance-enhanced multiphoton ionization">Resonance-enhanced multiphoton ionization</a> (REMPI)</li> <li><a href="/wiki/Raman_spectroscopy" title="Raman spectroscopy">Raman</a> <ul><li><a href="/wiki/Coherent_anti-Stokes_Raman_spectroscopy" title="Coherent anti-Stokes Raman spectroscopy">Coherent anti-Stokes</a></li></ul></li> <li><a href="/wiki/Raman_optical_activity" title="Raman optical activity">Raman optical activity</a></li> <li><a href="/wiki/Laser-induced_breakdown_spectroscopy" title="Laser-induced breakdown spectroscopy">Laser-induced breakdown</a></li> <li><a href="/wiki/Atomic_spectroscopy" title="Atomic spectroscopy">Atomic</a> <ul><li><a href="/wiki/Atomic_emission_spectroscopy" title="Atomic emission spectroscopy">emission</a> <ul><li><a href="/wiki/Glow-discharge_optical_emission_spectroscopy" title="Glow-discharge optical emission spectroscopy">Glow-discharge optical</a></li></ul></li> <li><a href="/wiki/Atomic_absorption_spectroscopy" title="Atomic absorption spectroscopy">absorption</a></li></ul></li> <li><a href="/wiki/Cavity_ring-down_spectroscopy" title="Cavity ring-down spectroscopy">Cavity ring-down spectroscopy</a></li> <li><a href="/wiki/Saturated_absorption_spectroscopy" title="Saturated absorption spectroscopy">Saturated absorption spectroscopy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">X-ray and Gamma ray</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/X-ray_spectroscopy" title="X-ray spectroscopy">X-ray</a> <ul><li><a href="/wiki/Energy-dispersive_X-ray_spectroscopy" title="Energy-dispersive X-ray spectroscopy">Energy-dispersive</a></li> <li><a href="/wiki/X-ray_emission_spectroscopy" title="X-ray emission spectroscopy">Emission</a></li> <li><a href="/wiki/Extended_X-ray_absorption_fine_structure" title="Extended X-ray absorption fine structure">Extended X-ray absorption fine structure</a></li></ul></li> <li><a href="/wiki/Gamma_spectroscopy" title="Gamma spectroscopy">Gamma</a></li> <li><a href="/wiki/M%C3%B6ssbauer_spectroscopy" title="Mössbauer spectroscopy">Mössbauer</a> <ul><li><a href="/wiki/Conversion_electron_M%C3%B6ssbauer_spectroscopy" title="Conversion electron Mössbauer spectroscopy">Conversion electron</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Electron</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Photoemission_spectroscopy" title="Photoemission spectroscopy">Photoelectron/photoemission</a> <ul><li><a href="/wiki/X-ray_photoelectron_spectroscopy" title="X-ray photoelectron spectroscopy">X-ray</a></li> <li><a href="/wiki/Ultraviolet_photoelectron_spectroscopy" title="Ultraviolet photoelectron spectroscopy">UV</a></li> <li><a href="/wiki/Angle-resolved_photoemission_spectroscopy" title="Angle-resolved photoemission spectroscopy">Angle-resolved</a></li> <li><a href="/wiki/Two-photon_photoelectron_spectroscopy" title="Two-photon photoelectron spectroscopy">Two-photon</a></li></ul></li> <li><a href="/wiki/Auger_electron_spectroscopy" title="Auger electron spectroscopy">Auger</a></li> <li><a href="/wiki/Electron_phenomenological_spectroscopy" title="Electron phenomenological spectroscopy">phenomenological</a></li> <li><a href="/wiki/Electron_paramagnetic_resonance" title="Electron paramagnetic resonance">paramagnetic</a></li> <li><a href="/wiki/Beta_spectroscopy" class="mw-redirect" title="Beta spectroscopy">Beta spectroscopy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Nucleon</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Alpha-particle_spectroscopy" title="Alpha-particle spectroscopy">Alpha</a></li> <li><a href="/wiki/Inelastic_neutron_scattering" class="mw-redirect" title="Inelastic neutron scattering">Inelastic neutron scattering</a> <ul><li><a href="/wiki/Neutron_spin_echo" title="Neutron spin echo">Neutron spin echo</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Radiowave</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Nuclear_magnetic_resonance_spectroscopy" title="Nuclear magnetic resonance spectroscopy">NMR</a> <ul><li><a href="/wiki/Two-dimensional_nuclear_magnetic_resonance_spectroscopy" title="Two-dimensional nuclear magnetic resonance spectroscopy">2D</a></li></ul></li> <li><a href="/wiki/Terahertz_spectroscopy_and_technology" title="Terahertz spectroscopy and technology">Terahertz</a></li> <li><a href="/wiki/Electron_paramagnetic_resonance" title="Electron paramagnetic resonance">ESR/EPR</a></li> <li><a href="/wiki/Ferromagnetic_resonance" title="Ferromagnetic resonance">Ferromagnetic resonance</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Others</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks hlist navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Data collection, processing</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fourier-transform_spectroscopy" title="Fourier-transform spectroscopy">Fourier-transform spectroscopy</a></li> <li><a href="/wiki/Hyperspectral_imaging" title="Hyperspectral imaging">Hyperspectral imaging</a></li> <li><a href="/wiki/Spectrophotometry" title="Spectrophotometry">Spectrophotometry</a></li> <li><a href="/wiki/Time_stretch_analog-to-digital_converter" class="mw-redirect" title="Time stretch analog-to-digital converter">Time-stretch</a></li> <li><a href="/wiki/Time-resolved_spectroscopy" title="Time-resolved spectroscopy">Time-resolved spectroscopy</a></li> <li><a href="/wiki/Video_spectroscopy" title="Video spectroscopy">Video spectroscopy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Measured phenomena</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Acoustic_resonance_spectroscopy" title="Acoustic resonance spectroscopy">Acoustic resonance spectroscopy</a></li> <li><a href="/wiki/Circular_dichroism" title="Circular dichroism">Circular dichroism spectroscopy</a></li> <li><a href="/wiki/Deep-level_transient_spectroscopy" title="Deep-level transient spectroscopy">Deep-level transient spectroscopy</a></li> <li><a href="/wiki/Dual-polarization_interferometry" title="Dual-polarization interferometry">Dual-polarization interferometry</a></li> <li><a href="/wiki/Hadron_spectroscopy" title="Hadron spectroscopy">Hadron spectroscopy</a></li> <li><a href="/wiki/Inelastic_electron_tunneling_spectroscopy" title="Inelastic electron tunneling spectroscopy">Inelastic electron tunneling spectroscopy</a> <ul><li><a href="/wiki/Scanning_tunneling_spectroscopy" title="Scanning tunneling spectroscopy">Scanning tunneling spectroscopy</a></li></ul></li> <li><a href="/wiki/Photoacoustic_spectroscopy" title="Photoacoustic spectroscopy">Photoacoustic spectroscopy</a></li> <li><a href="/wiki/Photothermal_spectroscopy" title="Photothermal spectroscopy">Photothermal spectroscopy</a></li> <li><a href="/wiki/Pump%E2%80%93probe_spectroscopy" class="mw-redirect" title="Pump–probe spectroscopy">Pump–probe spectroscopy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Applications</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Astronomical_spectroscopy" title="Astronomical spectroscopy">Astronomical spectroscopy</a></li> <li><a href="/wiki/Force_spectroscopy" title="Force spectroscopy">Force spectroscopy</a> (a misnomer)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Spectroscopy" title="Category:Spectroscopy">Category</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <b><a href="https://commons.wikimedia.org/wiki/Category:Spectroscopy" class="extiw" title="commons:Category:Spectroscopy">Commons</a></b></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Infrared_spectroscopy&oldid=1257824774">https://en.wikipedia.org/w/index.php?title=Infrared_spectroscopy&oldid=1257824774</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Category</a>: <ul><li><a href="/wiki/Category:Infrared_spectroscopy" title="Category:Infrared spectroscopy">Infrared spectroscopy</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_February_2024" title="Category:Articles with unsourced statements from February 2024">Articles with unsourced statements from February 2024</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_October_2019" title="Category:Articles with unsourced statements from October 2019">Articles with unsourced statements from October 2019</a></li><li><a href="/wiki/Category:Commons_category_link_from_Wikidata" title="Category:Commons category link from Wikidata">Commons category link from Wikidata</a></li><li><a href="/wiki/Category:Webarchive_template_wayback_links" title="Category:Webarchive template wayback links">Webarchive template wayback links</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 16 November 2024, at 20:45<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Infrared_spectroscopy&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-f69cdc8f6-ng8f6","wgBackendResponseTime":145,"wgPageParseReport":{"limitreport":{"cputime":"0.835","walltime":"1.078","ppvisitednodes":{"value":6315,"limit":1000000},"postexpandincludesize":{"value":214990,"limit":2097152},"templateargumentsize":{"value":9642,"limit":2097152},"expansiondepth":{"value":14,"limit":100},"expensivefunctioncount":{"value":6,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":220834,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 815.797 1 -total"," 43.22% 352.606 1 Template:Reflist"," 27.48% 224.168 30 Template:Cite_journal"," 14.98% 122.216 13 Template:Cn"," 13.21% 107.785 14 Template:Fix"," 11.70% 95.454 4 Template:Navbox"," 10.43% 85.085 1 Template:Branches_of_chemistry"," 6.78% 55.346 1 Template:Short_description"," 6.76% 55.181 1 Template:Commons_category"," 6.56% 53.532 1 Template:Sister_project"]},"scribunto":{"limitreport-timeusage":{"value":"0.491","limit":"10.000"},"limitreport-memusage":{"value":6232755,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-f69cdc8f6-qfk9f","timestamp":"20241122140608","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Infrared spectroscopy","url":"https:\/\/en.wikipedia.org\/wiki\/Infrared_spectroscopy","sameAs":"http:\/\/www.wikidata.org\/entity\/Q70906","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q70906","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2001-12-19T09:57:53Z","dateModified":"2024-11-16T20:45:06Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/2\/26\/Osiris-Rex_Ovirs_gsfc_20150619_2015-12655_019-023.jpg","headline":"involves the interaction of infrared radiation with matter"}</script> </body> </html>