CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-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-sticky-header-enabled vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Hydroxyl radical - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-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-sticky-header-enabled 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":"40159ef5-c545-415b-bbcc-2341079b753c","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Hydroxyl_radical","wgTitle":"Hydroxyl radical","wgCurRevisionId":1268592987,"wgRevisionId":1268592987,"wgArticleId":737798,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Articles with short description","Short description is different from Wikidata","Articles needing additional references from May 2010","All articles needing additional references","Articles without InChI source","Articles without UNII source","Articles containing unverified chemical infoboxes","Chembox image size set","Alcohols","Biological processes","Environmental chemistry","Free radicals","Hydroxides","Reactive intermediates"],"wgPageViewLanguage":"en", "wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Hydroxyl_radical","wgRelevantArticleId":737798,"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":30000,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q427071","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","mediawiki.page.gallery.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","ext.scribunto.logs","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"];</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.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cmediawiki.page.gallery.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.15"> <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/d/db/Hydroxyl_radical.svg/1200px-Hydroxyl_radical.svg.png"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="829"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Hydroxyl_radical.svg/800px-Hydroxyl_radical.svg.png"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="552"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Hydroxyl_radical.svg/640px-Hydroxyl_radical.svg.png"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="442"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Hydroxyl radical - 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/Hydroxyl_radical"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Hydroxyl_radical&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/Hydroxyl_radical"> <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-Hydroxyl_radical rootpage-Hydroxyl_radical 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" title="Main menu" > <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/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=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=Hydroxyl+radical" 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=Hydroxyl+radical" 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/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=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=Hydroxyl+radical" 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=Hydroxyl+radical" 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-Biological_significance" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Biological_significance"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Biological significance</span> </div> </a> <ul id="toc-Biological_significance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Importance_in_the_Earth's_atmosphere" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Importance_in_the_Earth's_atmosphere"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Importance in the Earth's atmosphere</span> </div> </a> <ul id="toc-Importance_in_the_Earth's_atmosphere-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Astronomical_importance" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Astronomical_importance"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Astronomical importance</span> </div> </a> <button aria-controls="toc-Astronomical_importance-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 Astronomical importance subsection</span> </button> <ul id="toc-Astronomical_importance-sublist" class="vector-toc-list"> <li id="toc-First_detection_of_interstellar_•HO" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#First_detection_of_interstellar_•HO"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>First detection of interstellar <sup>•</sup>HO</span> </div> </a> <ul id="toc-First_detection_of_interstellar_•HO-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Important_subsequent_reports_of_•HO_astronomical_detections" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Important_subsequent_reports_of_•HO_astronomical_detections"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Important subsequent reports of <sup>•</sup>HO astronomical detections</span> </div> </a> <ul id="toc-Important_subsequent_reports_of_•HO_astronomical_detections-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Energy_levels" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Energy_levels"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Energy levels</span> </div> </a> <ul id="toc-Energy_levels-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Chemistry_of_the_molecule_•HO" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Chemistry_of_the_molecule_•HO"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>Chemistry of the molecule <sup>•</sup>HO</span> </div> </a> <ul id="toc-Chemistry_of_the_molecule_•HO-sublist" class="vector-toc-list"> <li id="toc-•HO_production_pathways" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#•HO_production_pathways"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4.1</span> <span><i><sup>•</sup>HO production pathways</i></span> </div> </a> <ul id="toc-•HO_production_pathways-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-•HO_destruction_pathways" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#•HO_destruction_pathways"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4.2</span> <span><i><sup>•</sup>HO destruction pathways</i></span> </div> </a> <ul id="toc-•HO_destruction_pathways-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Rate_constants_and_relative_rates_for_important_formation_and_destruction_mechanisms" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Rate_constants_and_relative_rates_for_important_formation_and_destruction_mechanisms"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4.3</span> <span><i>Rate constants and relative rates for important formation and destruction mechanisms</i></span> </div> </a> <ul id="toc-Rate_constants_and_relative_rates_for_important_formation_and_destruction_mechanisms-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Importance_of_interstellar_•HO_observations" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Importance_of_interstellar_•HO_observations"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5</span> <span>Importance of interstellar <sup>•</sup>HO observations</span> </div> </a> <ul id="toc-Importance_of_interstellar_•HO_observations-sublist" class="vector-toc-list"> <li id="toc-•HO_as_a_tracer_of_shock_conditions" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#•HO_as_a_tracer_of_shock_conditions"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5.1</span> <span><sup>•</sup>HO as a tracer of shock conditions</span> </div> </a> <ul id="toc-•HO_as_a_tracer_of_shock_conditions-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-In_diffuse_clouds" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#In_diffuse_clouds"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5.2</span> <span>In diffuse clouds</span> </div> </a> <ul id="toc-In_diffuse_clouds-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-•HO_masers" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#•HO_masers"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5.3</span> <span><sup>•</sup>HO masers</span> </div> </a> <ul id="toc-•HO_masers-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </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">4</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">5</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">6</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" title="Table of Contents" > <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">Hydroxyl radical</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 22 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-22" 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">22 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%AC%D8%B0%D8%B1_%D8%A7%D9%84%D9%87%D9%8A%D8%AF%D8%B1%D9%88%D9%83%D8%B3%D9%8A%D9%84" title="جذر الهيدروكسيل – Arabic" lang="ar" hreflang="ar" data-title="جذر الهيدروكسيل" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-azb mw-list-item"><a href="https://azb.wikipedia.org/wiki/%D8%B1%D8%A7%D8%AF%DB%8C%DA%A9%D8%A7%D9%84_%D9%87%DB%8C%D8%AF%D8%B1%D9%88%DA%A9%D8%B3%DB%8C%D9%84" title="رادیکال هیدروکسیل – South Azerbaijani" lang="azb" hreflang="azb" data-title="رادیکال هیدروکسیل" data-language-autonym="تۆرکجه" data-language-local-name="South Azerbaijani" class="interlanguage-link-target"><span>تۆرکجه</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Hidroksil_radikal" title="Hidroksil radikal – Bosnian" lang="bs" hreflang="bs" data-title="Hidroksil radikal" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Radical_hidroxil" title="Radical hidroxil – Catalan" lang="ca" hreflang="ca" data-title="Radical hidroxil" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Hydroxyl-Radikal" title="Hydroxyl-Radikal – German" lang="de" hreflang="de" data-title="Hydroxyl-Radikal" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Radical_hidroxilo" title="Radical hidroxilo – Spanish" lang="es" hreflang="es" data-title="Radical hidroxilo" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B1%D8%A7%D8%AF%DB%8C%DA%A9%D8%A7%D9%84_%D9%87%DB%8C%D8%AF%D8%B1%D9%88%DA%A9%D8%B3%DB%8C%D9%84" title="رادیکال هیدروکسیل – Persian" lang="fa" hreflang="fa" data-title="رادیکال هیدروکسیل" 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/Radical_hydroxyle" title="Radical hydroxyle – French" lang="fr" hreflang="fr" data-title="Radical hydroxyle" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%ED%95%98%EC%9D%B4%EB%93%9C%EB%A1%9D%EC%8B%A4_%EB%9D%BC%EB%94%94%EC%B9%BC" title="하이드록실 라디칼 – Korean" lang="ko" hreflang="ko" data-title="하이드록실 라디칼" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Radikal_hidroksil" title="Radikal hidroksil – Indonesian" lang="id" hreflang="id" data-title="Radikal hidroksil" 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/Radicale_ossidrile" title="Radicale ossidrile – Italian" lang="it" hreflang="it" data-title="Radicale ossidrile" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Hidroksilradik%C4%81lis" title="Hidroksilradikālis – Latvian" lang="lv" hreflang="lv" data-title="Hidroksilradikālis" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Hidroxilgy%C3%B6k" title="Hidroxilgyök – Hungarian" lang="hu" hreflang="hu" data-title="Hidroxilgyök" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Hydroxylradicaal" title="Hydroxylradicaal – Dutch" lang="nl" hreflang="nl" data-title="Hydroxylradicaal" 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/%E3%83%92%E3%83%89%E3%83%AD%E3%82%AD%E3%82%B7%E3%83%AB%E3%83%A9%E3%82%B8%E3%82%AB%E3%83%AB" title="ヒドロキシルラジカル – Japanese" lang="ja" hreflang="ja" data-title="ヒドロキシルラジカル" 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-nds mw-list-item"><a href="https://nds.wikipedia.org/wiki/Hydroxyl-Radikal" title="Hydroxyl-Radikal – Low German" lang="nds" hreflang="nds" data-title="Hydroxyl-Radikal" data-language-autonym="Plattdüütsch" data-language-local-name="Low German" class="interlanguage-link-target"><span>Plattdüütsch</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Hydroxylov%C3%BD_radik%C3%A1l" title="Hydroxylový radikál – Slovak" lang="sk" hreflang="sk" data-title="Hydroxylový radikál" 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/Hidroksilni_radikal" title="Hidroksilni radikal – Slovenian" lang="sl" hreflang="sl" data-title="Hidroksilni radikal" 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/Hidroksil_radikal" title="Hidroksil radikal – Serbian" lang="sr" hreflang="sr" data-title="Hidroksil radikal" 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/Hidroksil_radikal" title="Hidroksil radikal – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Hidroksil radikal" 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-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Hydroxylradikal" title="Hydroxylradikal – Swedish" lang="sv" hreflang="sv" data-title="Hydroxylradikal" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E7%BE%9F%E8%87%AA%E7%94%B1%E5%9F%BA" title="羟自由基 – Chinese" lang="zh" hreflang="zh" data-title="羟自由基" 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/Q427071#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/Hydroxyl_radical" 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:Hydroxyl_radical" 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/Hydroxyl_radical"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Hydroxyl_radical&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=Hydroxyl_radical&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/Hydroxyl_radical"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Hydroxyl_radical&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=Hydroxyl_radical&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/Hydroxyl_radical" 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/Hydroxyl_radical" 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="//en.wikipedia.org/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=Hydroxyl_radical&oldid=1268592987" 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=Hydroxyl_radical&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=Hydroxyl_radical&id=1268592987&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%2FHydroxyl_radical"><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%2FHydroxyl_radical"><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=Hydroxyl_radical&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=Hydroxyl_radical&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:Hydroxyl_radical" hreflang="en"><span>Wikimedia Commons</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/Q427071" 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"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Neutral form of hydroxide, OH•</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Hydroxyl_radical" title="Special:EditPage/Hydroxyl radical">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Hydroxyl+radical%22">"Hydroxyl radical"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Hydroxyl+radical%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Hydroxyl+radical%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Hydroxyl+radical%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Hydroxyl+radical%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Hydroxyl+radical%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">May 2010</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r1268415487">.mw-parser-output .ib-chembox{border-collapse:collapse;text-align:left}.mw-parser-output .ib-chembox td,.mw-parser-output .ib-chembox th{border:1px solid #a2a9b1;width:40%}.mw-parser-output .ib-chembox td+td{width:60%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .ib-chembox figure:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent){background:var(--background-color-inverted,#f8f9fa)}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .ib-chembox figure:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent){background:var(--background-color-inverted,#f8f9fa)}}</style> <table class="infobox ib-chembox"> <caption>Hydroxyl radical </caption> <tbody><tr> <td colspan="2" style="text-align:center; padding:2px;"><figure class="mw-halign-center" typeof="mw:File"><a href="/wiki/File:Hydroxyl_radical.svg" class="mw-file-description" title="Stick model of the hydroxyl radical with molecular orbitals"><img alt="Stick model of the hydroxyl radical with molecular orbitals" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/db/Hydroxyl_radical.svg/180px-Hydroxyl_radical.svg.png" decoding="async" width="180" height="124" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/db/Hydroxyl_radical.svg/270px-Hydroxyl_radical.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/db/Hydroxyl_radical.svg/360px-Hydroxyl_radical.svg.png 2x" data-file-width="42" data-file-height="29" /></a><figcaption>Stick model of the hydroxyl radical with molecular orbitals</figcaption></figure> </td></tr> <tr> <td colspan="2" style="text-align:center; padding:2px;"><figure class="mw-halign-center" typeof="mw:File"><a href="/wiki/File:OH_orb5.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/8d/OH_orb5.jpg/180px-OH_orb5.jpg" decoding="async" width="180" height="151" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/8d/OH_orb5.jpg/270px-OH_orb5.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/8d/OH_orb5.jpg/360px-OH_orb5.jpg 2x" data-file-width="914" data-file-height="765" /></a><figcaption></figcaption></figure> </td></tr> <tr> <td colspan="2" class="borderless" style="text-align:center"> <table border="0" style="width:100%;display:inline-table;"> <tbody><tr> <td style="border-right:1px solid #aaa; width:50%;"><figure class="mw-halign-center" typeof="mw:File"><a href="/wiki/File:Hydroxide_anion_or_hydroxyl_radical_spacefill.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Hydroxide_anion_or_hydroxyl_radical_spacefill.png/110px-Hydroxide_anion_or_hydroxyl_radical_spacefill.png" decoding="async" width="110" height="104" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Hydroxide_anion_or_hydroxyl_radical_spacefill.png/165px-Hydroxide_anion_or_hydroxyl_radical_spacefill.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Hydroxide_anion_or_hydroxyl_radical_spacefill.png/220px-Hydroxide_anion_or_hydroxyl_radical_spacefill.png 2x" data-file-width="2000" data-file-height="1887" /></a><figcaption></figcaption></figure> </td> <td style="width:50%;"><figure class="mw-halign-center" typeof="mw:File"><a href="/wiki/File:Hydroxide_anion_or_hydroxyl_radical_ball.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Hydroxide_anion_or_hydroxyl_radical_ball.png/110px-Hydroxide_anion_or_hydroxyl_radical_ball.png" decoding="async" width="110" height="95" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Hydroxide_anion_or_hydroxyl_radical_ball.png/165px-Hydroxide_anion_or_hydroxyl_radical_ball.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Hydroxide_anion_or_hydroxyl_radical_ball.png/220px-Hydroxide_anion_or_hydroxyl_radical_ball.png 2x" data-file-width="2000" data-file-height="1725" /></a><figcaption></figcaption></figure> </td></tr></tbody></table> </td></tr> <tr> <th colspan="2" style="background: #f8eaba;color:inherit; text-align: center;">Names </th></tr> <tr> <td colspan="2" style="text-align:left;"><a href="/wiki/Chemical_nomenclature" title="Chemical nomenclature">IUPAC name</a> <div style="max-width:22em; word-wrap:break-word; padding-left:1.7em;">Hydroxyl radical</div> </td></tr> <tr> <td colspan="2" style="text-align:left;"><a href="/wiki/Chemical_nomenclature#Systematic_name" title="Chemical nomenclature">Systematic IUPAC name</a> <div style="max-width:22em; word-wrap:break-word; padding-left:1.7em;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0; max-width:22em;"><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="plainlist"><ul><li>Oxidanyl<sup id="cite_ref-Hydroxyl_(CHEBI:29191)_1-0" class="reference"><a href="#cite_note-Hydroxyl_(CHEBI:29191)-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> (substitutive)</li><li>Hydridooxygen(•)<sup id="cite_ref-Hydroxyl_(CHEBI:29191)_1-1" class="reference"><a href="#cite_note-Hydroxyl_(CHEBI:29191)-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> (additive)</li></ul></div></div></div> </td></tr> <tr> <td colspan="2" style="text-align:left;">Other names <div style="max-width:22em; word-wrap:break-word; padding-left:1.7em;"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li>Hydroxy</li><li>Hydroxyl</li><li>λ<sup>1</sup>-Oxidanyl</li></ul></div></div> </td></tr> <tr> <th colspan="2" style="background: #f8eaba;color:inherit; text-align: center;">Identifiers </th></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/CAS_Registry_Number" title="CAS Registry Number">CAS Number</a></div> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="commonchemistry.cas.org"><a rel="nofollow" class="external text" href="https://commonchemistry.cas.org/detail?cas_rn=3352-57-6">3352-57-6</a></span></li></ul></div> </td></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">3D model (<a href="/wiki/JSmol" class="mw-redirect" title="JSmol">JSmol</a>)</div> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="chemapps.stolaf.edu (3D interactive model)"><a rel="nofollow" class="external text" href="https://chemapps.stolaf.edu/jmol/jmol.php?model=%5BOH%5D">Interactive image</a></span></li></ul></div> </td></tr> <tr> <td><a href="/wiki/ChEBI" title="ChEBI">ChEBI</a> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="www.ebi.ac.uk"><a rel="nofollow" class="external text" href="https://www.ebi.ac.uk/chebi/searchId.do?chebiId=29191">CHEBI:29191</a></span></li></ul></div> </td></tr> <tr> <td><a href="/wiki/ChemSpider" title="ChemSpider">ChemSpider</a> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="www.chemspider.com"><a rel="nofollow" class="external text" href="https://www.chemspider.com/Chemical-Structure.138477.html">138477</a></span><sup> <span typeof="mw:File"><span><img alt="check" src="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png" decoding="async" width="7" height="7" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/11px-Yes_check.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/14px-Yes_check.svg.png 2x" data-file-width="600" data-file-height="600" /></span></span><span style="display:none">Y</span></sup></li></ul></div> </td></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/Gmelin_database" title="Gmelin database">Gmelin Reference</a></div> </td> <td>105 </td></tr> <tr> <td><a href="/wiki/KEGG" title="KEGG">KEGG</a> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="www.kegg.jp"><a rel="nofollow" class="external text" href="https://www.kegg.jp/entry/C16844">C16844</a></span><sup> <span typeof="mw:File"><span><img alt="check" src="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png" decoding="async" width="7" height="7" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/11px-Yes_check.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/14px-Yes_check.svg.png 2x" data-file-width="600" data-file-height="600" /></span></span><span style="display:none">Y</span></sup></li></ul></div> </td></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/PubChem" title="PubChem">PubChem</a> <abbr title="Compound ID">CID</abbr></div> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="pubchem.ncbi.nlm.nih.gov"><a rel="nofollow" class="external text" href="https://pubchem.ncbi.nlm.nih.gov/compound/157350">157350</a></span></li></ul></div> </td></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/CompTox_Chemicals_Dashboard" title="CompTox Chemicals Dashboard">CompTox Dashboard</a> <span style="font-weight:normal">(<abbr title="U.S. Environmental Protection Agency">EPA</abbr>)</span></div> </td> <td><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"><div class="plainlist"><ul><li><span title="comptox.epa.gov"><a rel="nofollow" class="external text" href="https://comptox.epa.gov/dashboard/chemical/details/DTXSID901318744">DTXSID901318744</a> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q427071#P3117" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></li></ul></div> </td></tr> <tr> <td colspan="2"><div class="collapsible-list mw-collapsible mw-collapsed" style="text-align: left;"> <div style="line-height: 1.6em; font-weight: bold; text-align:left; font-weight:normal;"><div><a href="/wiki/International_Chemical_Identifier" title="International Chemical Identifier">InChI</a></div></div> <ul class="mw-collapsible-content" style="margin-top: 0; margin-bottom: 0; line-height: inherit; list-style: none; margin-left: 0; word-break:break-all;"><li style="line-height: inherit; margin: 0"><div style="border-top:1px solid #ccc; padding:0.2em 0 0.2em 1.5em; text-align:left;"><div style="word-wrap:break-word; text-indent:-1.5em; font-size:97%; line-height:120%;">InChI=1S/HO/h1H<sup> <span typeof="mw:File"><span><img alt="check" src="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png" decoding="async" width="7" height="7" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/11px-Yes_check.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/14px-Yes_check.svg.png 2x" data-file-width="600" data-file-height="600" /></span></span><span style="display:none">Y</span></sup></div><div style="word-wrap:break-word; text-indent:-1.5em; font-size:97%; line-height:120%;">Key: TUJKJAMUKRIRHC-UHFFFAOYSA-N<sup> <span typeof="mw:File"><span><img alt="check" src="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png" decoding="async" width="7" height="7" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/11px-Yes_check.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/14px-Yes_check.svg.png 2x" data-file-width="600" data-file-height="600" /></span></span><span style="display:none">Y</span></sup></div></div></li></ul> </div> </td></tr> <tr> <td colspan="2"><div class="collapsible-list mw-collapsible mw-collapsed" style="text-align: left;"> <div style="line-height: 1.6em; font-weight: bold; text-align:left; font-weight:normal;"><div><a href="/wiki/Simplified_molecular-input_line-entry_system" class="mw-redirect" title="Simplified molecular-input line-entry system">SMILES</a></div></div> <ul class="mw-collapsible-content" style="margin-top: 0; margin-bottom: 0; line-height: inherit; list-style: none; margin-left: 0; word-break:break-all;"><li style="line-height: inherit; margin: 0"><div style="border-top:1px solid #ccc; padding:0.2em 0 0.2em 1.6em; word-wrap:break-word; text-indent:-1.5em; text-align:left; font-size:97%; line-height:120%;">[OH]</div></li></ul> </div> </td></tr> <tr> <th colspan="2" style="background: #f8eaba;color:inherit; text-align: center;">Properties </th></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/Chemical_formula" title="Chemical formula">Chemical formula</a></div> </td> <td><span title="Hydrogen">H</span><span title="Oxygen">O</span> </td></tr> <tr> <td><a href="/wiki/Molar_mass" title="Molar mass">Molar mass</a> </td> <td><span class="nowrap"><span data-sort-value="7001170070000000000♠"></span>17.007</span> g·mol<sup>−1</sup>   </td></tr> <tr> <td><a href="/wiki/Acid_dissociation_constant" title="Acid dissociation constant">Acidity</a> (p<i>K</i><sub>a</sub>) </td> <td>11.8 to 11.9<sup id="cite_ref-P82db_2-0" class="reference"><a href="#cite_note-P82db-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <th colspan="2" style="background: #f8eaba;color:inherit; text-align: center;">Thermochemistry </th></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/Standard_molar_entropy" title="Standard molar entropy">Std molar<br />entropy</a> <span style="font-size:112%;">(<i>S</i><sup>⦵</sup><sub>298</sub>)</span></div> </td> <td>183.71 J K<sup>−1</sup> mol<sup>−1</sup> </td></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/Standard_enthalpy_change_of_formation" class="mw-redirect" title="Standard enthalpy change of formation">Std enthalpy of<br />formation</a> <span style="font-size:112%;">(Δ<sub>f</sub><i>H</i><sup>⦵</sup><sub>298</sub>)</span></div> </td> <td>38.99 kJ mol<sup>−1</sup> </td></tr> <tr> <th colspan="2" style="background: #f8eaba;color:inherit; text-align: center;">Related compounds </th></tr> <tr> <td><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Related compounds</div> </td> <td><a href="/wiki/Dioxidanylium" title="Dioxidanylium">O<sub>2</sub>H<sup>+</sup></a><br /><a href="/wiki/Hydroxide" title="Hydroxide">OH<sup>−</sup></a><br /><a href="/wiki/Peroxide" title="Peroxide">O<sub>2</sub><sup>2−</sup></a> </td></tr> <tr> <td colspan="2" style="text-align:left; background:#f8eaba; color:inherit; border:1px solid #a2a9b1;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Except where otherwise noted, data are given for materials in their <a href="/wiki/Standard_state" title="Standard state">standard state</a> (at 25 °C [77 °F], 100 kPa).</div> <div style="margin-top: 0.3em;"></div> <div style="margin-top: 0.3em; text-align: center;"><a href="/wiki/Wikipedia:Chemical_infobox#References" title="Wikipedia:Chemical infobox">Infobox references</a></div> </td></tr> </tbody></table><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Chemical compound</div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Pyrithione-tautomerism-2D-skeletal.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Pyrithione-tautomerism-2D-skeletal.png/220px-Pyrithione-tautomerism-2D-skeletal.png" decoding="async" width="220" height="92" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Pyrithione-tautomerism-2D-skeletal.png/330px-Pyrithione-tautomerism-2D-skeletal.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Pyrithione-tautomerism-2D-skeletal.png/440px-Pyrithione-tautomerism-2D-skeletal.png 2x" data-file-width="1100" data-file-height="460" /></a><figcaption><a href="/wiki/Skeletal_formula" title="Skeletal formula">Skeletal formulae</a> of <a href="/wiki/Pyrithione" title="Pyrithione">1-hydroxy-2(<i>1H</i>)-pyridinethione</a> and its <a href="/wiki/Tautomer" title="Tautomer">tautomer</a></figcaption></figure> <p>The <b>hydroxyl radical</b>, <b><sup>•</sup>HO</b>, is the neutral form of the <a href="/wiki/Hydroxide_ion" class="mw-redirect" title="Hydroxide ion">hydroxide ion</a> (HO<sup>–</sup>). Hydroxyl radicals are highly reactive and consequently short-lived; however, they form an important part of <a href="/wiki/Radical_(chemistry)" title="Radical (chemistry)">radical chemistry</a>. Most notably hydroxyl radicals are produced from the decomposition of <a href="/wiki/Organic_peroxide" class="mw-redirect" title="Organic peroxide">hydroperoxides</a> (ROOH) or, in <a href="/wiki/Atmospheric_chemistry" title="Atmospheric chemistry">atmospheric chemistry</a>, by the reaction of <a href="/wiki/Excited_state" title="Excited state">excited</a> <a href="/wiki/Atomic_oxygen" class="mw-redirect" title="Atomic oxygen">atomic oxygen</a> with water. It is also an important radical formed in radiation chemistry, since it leads to the formation of <a href="/wiki/Hydrogen_peroxide" title="Hydrogen peroxide">hydrogen peroxide</a> and <a href="/wiki/Oxygen" title="Oxygen">oxygen</a>, which can enhance <a href="/wiki/Corrosion" title="Corrosion">corrosion</a> and <a href="/wiki/Stress_corrosion_cracking" title="Stress corrosion cracking">stress corrosion cracking</a> in coolant systems subjected to radioactive environments. Hydroxyl radicals are also produced during UV-light dissociation of H<sub>2</sub>O<sub>2</sub> (suggested in 1879) and likely in <a href="/wiki/Fenton%27s_reagent" title="Fenton's reagent">Fenton chemistry</a>, where trace amounts of reduced transition metals catalyze peroxide-mediated oxidations of organic compounds. </p><p>In <a href="/wiki/Organic_synthesis" title="Organic synthesis">organic synthesis</a> hydroxyl radicals are most commonly generated by <a href="/wiki/Photolysis" class="mw-redirect" title="Photolysis">photolysis</a> of <i><a href="/wiki/1-Hydroxy-2(1H)-pyridinethione" class="mw-redirect" title="1-Hydroxy-2(1H)-pyridinethione">1-Hydroxy-2(1H)-pyridinethione</a></i>. </p><p>The hydroxyl radical is often referred to as the "detergent" of the <a href="/wiki/Troposphere" title="Troposphere">troposphere</a> because it reacts with many pollutants, often acting as the first step to their removal. It also has an important role in eliminating some <a href="/wiki/Greenhouse_gas" title="Greenhouse gas">greenhouse gases</a> like <a href="/wiki/Methane" title="Methane">methane</a> and <a href="/wiki/Ozone" title="Ozone">ozone</a>.<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> The rate of reaction with the hydroxyl radical often determines how long many pollutants last in the atmosphere, if they do not undergo <a href="/wiki/Photolysis" class="mw-redirect" title="Photolysis">photolysis</a> or are <a href="/wiki/Precipitation" title="Precipitation">rained out</a>. For instance, methane, which reacts relatively slowly with hydroxyl radicals, has an average lifetime of >5 years and many <a href="/wiki/Chlorofluorocarbon" title="Chlorofluorocarbon">CFCs</a> have lifetimes of 50+ years. Pollutants, such as larger <a href="/wiki/Hydrocarbons" class="mw-redirect" title="Hydrocarbons">hydrocarbons</a>, can have very short average lifetimes of less than a few hours. </p><p>The first reaction with many <a href="/wiki/Volatile_organic_compounds" class="mw-redirect" title="Volatile organic compounds">volatile organic compounds</a> (VOCs) is the removal of a hydrogen atom, forming water and an <a href="/wiki/Alkyl" class="mw-redirect" title="Alkyl">alkyl</a> radical (R<sup>•</sup>): </p> <dl><dd><sup>•</sup>HO + RH → H<sub>2</sub>O + R<sup>•</sup></dd></dl> <p>The alkyl radical will typically react rapidly with <a href="/wiki/Oxygen" title="Oxygen">oxygen</a> forming a <a href="/wiki/Peroxy" class="mw-redirect" title="Peroxy">peroxy</a> radical: </p> <dl><dd>R<sup>•</sup> + O<sub>2</sub> → RO<sub>2</sub></dd></dl> <p>The fate of this radical in the <a href="/wiki/Troposphere" title="Troposphere">troposphere</a> is dependent on factors such as the amount of sunlight, pollution in the atmosphere and the nature of the <a href="/wiki/Alkyl" class="mw-redirect" title="Alkyl">alkyl</a> radical that formed it (See chapters 12 & 13 in External Links "University Lecture notes on Atmospheric chemistry) </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Biological_significance">Biological significance</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=1" title="Edit section: Biological significance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Hydroxyl radicals can occasionally be produced as a byproduct of <a href="/wiki/Immune_system" title="Immune system">immune action</a>. <a href="/wiki/Macrophage" title="Macrophage">Macrophages</a> and <a href="/wiki/Microglia" title="Microglia">microglia</a> most frequently generate this compound when exposed to very specific <a href="/wiki/Pathogen" title="Pathogen">pathogens</a>, such as certain bacteria. The destructive action of hydroxyl radicals has been implicated in several <a href="/wiki/Neurological" class="mw-redirect" title="Neurological">neurological</a> <a href="/wiki/Autoimmune_disorder" class="mw-redirect" title="Autoimmune disorder">autoimmune diseases</a> such as <a href="/wiki/HIV-associated_dementia" class="mw-redirect" title="HIV-associated dementia">HIV-associated dementia</a>, when immune cells become over-activated and toxic to neighboring healthy cells.<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>The hydroxyl radical can damage virtually all types of macromolecules: carbohydrates, nucleic acids (<a href="/wiki/Mutation" title="Mutation">mutations</a>), lipids (<a href="/wiki/Lipid_peroxidation" title="Lipid peroxidation">lipid peroxidation</a>) and amino acids (e.g. conversion of <a href="/wiki/Phenylalanine" title="Phenylalanine">Phe</a> to m-<a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a> and o-<a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a>). The hydroxyl radical has a very short <i><a href="/wiki/In_vivo" title="In vivo">in vivo</a></i> <a href="/wiki/Half-life" title="Half-life">half-life</a> of approximately 10<sup>−9</sup> seconds and a high reactivity.<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> This makes it a very dangerous compound to the organism.<sup id="cite_ref-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11_6-0" class="reference"><a href="#cite_note-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11-6"><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>Unlike <a href="/wiki/Superoxide" title="Superoxide">superoxide</a>, which can be detoxified by <a href="/wiki/Superoxide_dismutase" title="Superoxide dismutase">superoxide dismutase</a>, the hydroxyl radical cannot be eliminated by an <a href="/wiki/Enzyme" title="Enzyme">enzymatic</a> reaction. Mechanisms for scavenging peroxyl radicals for the protection of <a href="/wiki/Cell_(biology)" title="Cell (biology)">cellular</a> structures include endogenous <a href="/wiki/Antioxidants" class="mw-redirect" title="Antioxidants">antioxidants</a> such as <a href="/wiki/Melatonin" title="Melatonin">melatonin</a> and <a href="/wiki/Glutathione" title="Glutathione">glutathione</a>, and dietary <a href="/wiki/Antioxidants" class="mw-redirect" title="Antioxidants">antioxidants</a> such as <a href="/wiki/Mannitol" title="Mannitol">mannitol</a> and <a href="/wiki/Vitamin_E" title="Vitamin E">vitamin E</a>.<sup id="cite_ref-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11_6-1" class="reference"><a href="#cite_note-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Importance_in_the_Earth's_atmosphere"><span id="Importance_in_the_Earth.27s_atmosphere"></span>Importance in the Earth's atmosphere</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=2" title="Edit section: Importance in the Earth's atmosphere"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The hydroxyl <sup>•</sup>HO radicals is one of the main chemical species controlling the oxidizing capacity of the Earth's atmosphere, having a major impact on the concentrations and distribution of greenhouse gases and pollutants. It is the most widespread oxidizer in the <a href="/wiki/Troposphere" title="Troposphere">troposphere</a>, the lowest part of the atmosphere. Understanding <sup>•</sup>HO variability is important to evaluating human impacts on the atmosphere and climate. The <sup>•</sup>HO species has a lifetime in the Earth atmosphere of less than one second.<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> Understanding the role of <sup>•</sup>HO in the oxidation process of methane (CH<sub>4</sub>) present in the atmosphere to first carbon monoxide (CO) and then carbon dioxide (CO<sub>2</sub>) is important for assessing the residence time of this greenhouse gas, the overall carbon budget of the troposphere, and its influence on the process of global warming. The lifetime of <sup>•</sup>HO radicals in the Earth atmosphere is very short, therefore <sup>•</sup>HO concentrations in the air are very low and very sensitive techniques are required for its direct detection.<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> Global average hydroxyl radical concentrations have been measured indirectly by analyzing <a href="/wiki/Methyl_chloroform" class="mw-redirect" title="Methyl chloroform">methyl chloroform</a> (CH<sub>3</sub>CCl<sub>3</sub>) present in the air. The results obtained by Montzka <i>et al.</i> (2011)<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> shows that the interannual variability in <sup>•</sup>HO estimated from CH<sub>3</sub>CCl<sub>3</sub> measurements is small, indicating that global <sup>•</sup>HO is generally well buffered against perturbations. This small variability is consistent with measurements of <a href="/wiki/Methane" title="Methane">methane</a> and other trace gases primarily oxidized by <sup>•</sup>HO, as well as global photochemical model calculations. </p> <div class="mw-heading mw-heading2"><h2 id="Astronomical_importance">Astronomical importance</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=3" title="Edit section: Astronomical importance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="First_detection_of_interstellar_•HO"><span id="First_detection_of_interstellar_.E2.80.A2HO"></span>First detection of interstellar <sup>•</sup>HO</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=4" title="Edit section: First detection of interstellar •HO"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The first experimental evidence for the presence of 18 cm absorption lines of the hydroxyl (<sup>•</sup>HO) radical in the radio absorption spectrum of <a href="/wiki/Cassiopeia_A" title="Cassiopeia A">Cassiopeia A</a> was obtained by Weinreb et al. (Nature, Vol. 200, pp. 829, 1963) based on observations made during the period October 15–29, 1963.<sup id="cite_ref-DieterEwen1964_11-0" class="reference"><a href="#cite_note-DieterEwen1964-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Important_subsequent_reports_of_•HO_astronomical_detections"><span id="Important_subsequent_reports_of_.E2.80.A2HO_astronomical_detections"></span>Important subsequent reports of <sup>•</sup>HO astronomical detections</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=5" title="Edit section: Important subsequent reports of •HO astronomical detections"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable" border="1"> <tbody><tr> <th><b>Year</b> </th> <th><b>Description</b> </th></tr> <tr> <td>1967 </td> <td><i><sup>•</sup>HO Molecules in the Interstellar Medium</i>. Robinson and McGee. One of the first observational reviews of <sup>•</sup>HO observations. <sup>•</sup>HO had been observed in absorption and emission, but at this time the processes which populate the energy levels are not yet known with certainty, so the article does not give good estimates of <sup>•</sup>HO densities.<sup id="cite_ref-RobinsonMcGee1967_12-0" class="reference"><a href="#cite_note-RobinsonMcGee1967-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1967 </td> <td><i>Normal <sup>•</sup>HO Emission and Interstellar Dust Clouds</i>. Heiles. First detection of normal emission from <sup>•</sup>HO in interstellar dust clouds.<sup id="cite_ref-Heiles1968_13-0" class="reference"><a href="#cite_note-Heiles1968-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1971 </td> <td><i>Interstellar molecules and dense clouds</i>.D. M. Rank, C. H. Townes, and W. J. Welch. Review of the epoch about molecular line emission of molecules through dense clouds.<sup id="cite_ref-RankTownes1971_14-0" class="reference"><a href="#cite_note-RankTownes1971-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1980 </td> <td><i><sup>•</sup>HO observations of molecular complexes in Orion and Taurus</i>. Baud and Wouterloot. Map of <sup>•</sup>HO emission in molecular complexes Orion and Taurus. Derived column densities are in good agreement with previous CO results.<sup id="cite_ref-BaudWouterloot1980_15-0" class="reference"><a href="#cite_note-BaudWouterloot1980-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1981 </td> <td><i>Emission-absorption observations of HO in diffuse interstellar clouds</i>. Dickey, Crovisier and Kazès. Observations of fifty eight regions which show HI absorption were studied. Typical densities and excitation temperature for diffuse clouds are determined in this article.<sup id="cite_ref-DickeyCrovisier1981_16-0" class="reference"><a href="#cite_note-DickeyCrovisier1981-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1981 </td> <td><i>Magnetic fields in molecular clouds — <sup>•</sup>HO Zeeman observations</i>. Crutcher, Troland and Heiles. <sup>•</sup>HO Zeeman observations of the absorption lines produced in interstellar dust clouds toward 3C 133, 3C 123, and W51.<sup id="cite_ref-CrutcherTroland1981_17-0" class="reference"><a href="#cite_note-CrutcherTroland1981-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1981 </td> <td><i>Detection of interstellar HO in the Far-Infrared</i>. J. Storey, D. Watson, C. Townes. Strong absorption lines of <sup>•</sup>HO were detected at wavelengths of 119.23 and 119.44 microns in the direction of Sgr B2.<sup id="cite_ref-StoreyWatson1981_18-0" class="reference"><a href="#cite_note-StoreyWatson1981-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td>1989 </td> <td><i>Molecular outflows in powerful HO megamasers</i>. Baan, Haschick and Henkel. Observations of <sup>•</sup>H and <sup>•</sup>HO molecular emission through <sup>•</sup>HO megamasers galaxies, in order to get a FIR luminosity and maser activity relation.<sup id="cite_ref-BaanHaschick1989_19-0" class="reference"><a href="#cite_note-BaanHaschick1989-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Energy_levels">Energy levels</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=6" title="Edit section: Energy levels"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><sup>•</sup>HO is a diatomic molecule. The electronic angular momentum along the molecular axis is +1 or -1, and the electronic spin angular momentum S=1/2. Because of the orbit-spin coupling, the spin angular momentum can be oriented in parallel or anti parallel directions to the orbital angular momentum, producing the splitting into Π<sub>1/2</sub> and Π<sub>3/2</sub> states. The <sup>2</sup>Π<sub>3/2</sub> ground state of <sup>•</sup>HO is split by lambda doubling interaction (an interaction between the nuclei rotation and the unpaired electron motion around its orbit). Hyperfine interaction with the unpaired spin of the proton further splits the levels. </p> <ul class="gallery mw-gallery-traditional"> </ul> <div class="mw-heading mw-heading3"><h3 id="Chemistry_of_the_molecule_•HO"><span id="Chemistry_of_the_molecule_.E2.80.A2HO"></span>Chemistry of the molecule <sup>•</sup>HO</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=7" title="Edit section: Chemistry of the molecule •HO"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>In order to study gas phase interstellar chemistry, it is convenient to distinguish two types of interstellar clouds: diffuse clouds, with T=30-100 K, and n=10–1000 cm<sup>−3</sup>, and dense clouds with T=10-30K and density n=<span class="nowrap"><span data-sort-value="7004100000000000000♠"></span>10<sup>4</sup></span>-<span class="nowrap"><span data-sort-value="7003100000000000000♠"></span>10<sup>3</sup> cm<sup>−3</sup></span>. Ion chemical routes in both dense and diffuse clouds have been established for some works (Hartquist 1990). </p> <div class="mw-heading mw-heading4"><h4 id="•HO_production_pathways"><span id=".E2.80.A2HO_production_pathways"></span><i><sup>•</sup>HO production pathways</i></h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=8" title="Edit section: •HO production pathways"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <sup>•</sup>HO radical is linked with the production of H<sub>2</sub>O in molecular clouds. Studies of <sup>•</sup>HO distribution in Taurus Molecular Cloud-1 (TMC-1)<sup id="cite_ref-HarjuWinnberg2000_20-0" class="reference"><a href="#cite_note-HarjuWinnberg2000-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> suggest that in dense gas, <sup>•</sup>HO is mainly formed by dissociative recombination of H<sub>3</sub>O<sup>+</sup>. Dissociative recombination is the reaction in which a molecular ion recombines with an electron and dissociates into neutral fragments. Important formation mechanisms for <sup>•</sup>HO are: </p><p>H<sub>3</sub>O<sup>+</sup> + e<sup>−</sup> → <sup>•</sup>HO + H<sub>2</sub> (1a) Dissociative recombination </p><p>H<sub>3</sub>O<sup>+</sup> + e<sup>−</sup> → <sup>•</sup>HO + <sup>•</sup>H + <sup>•</sup>H (1b) Dissociative recombination </p><p>HCO<sub>2</sub><sup>+</sup> + e<sup>−</sup> → <sup>•</sup>HO + CO (2a) Dissociative recombination </p><p><sup>•</sup>O + HCO → <sup>•</sup>HO + CO (3a) Neutral-neutral </p><p>H<sup>−</sup> + H<sub>3</sub>O<sup>+</sup> → <sup>•</sup>HO + H<sub>2</sub> + <sup>•</sup>H (4a) Ion-molecular ion neutralization </p> <div class="mw-heading mw-heading4"><h4 id="•HO_destruction_pathways"><span id=".E2.80.A2HO_destruction_pathways"></span><i><sup>•</sup>HO destruction pathways</i></h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=9" title="Edit section: •HO destruction pathways"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Experimental data on association reactions of <sup>•</sup>H and <sup>•</sup>HO suggest that radiative association involving atomic and diatomic neutral radicals may be considered as an effective mechanism for the production of small neutral molecules in the interstellar clouds.<sup id="cite_ref-FieldAdams1980_21-0" class="reference"><a href="#cite_note-FieldAdams1980-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> The formation of O<sub>2</sub> occurs in the gas phase via the neutral exchange reaction between <sup>•</sup>O and <sup>•</sup>HO, which is also the main sink for <sup>•</sup>HO in dense regions.<sup id="cite_ref-HarjuWinnberg2000_20-1" class="reference"><a href="#cite_note-HarjuWinnberg2000-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p><p>We can see that atomic oxygen takes part both in the production and destruction of <sup>•</sup>HO, so the abundance of <sup>•</sup>HO depends mainly on the <style data-mw-deduplicate="TemplateStyles:r1123817410">.mw-parser-output .template-chem2-su{display:inline-block;font-size:80%;line-height:1;vertical-align:-0.35em}.mw-parser-output .template-chem2-su>span{display:block;text-align:left}.mw-parser-output sub.template-chem2-sub{font-size:80%;vertical-align:-0.35em}.mw-parser-output sup.template-chem2-sup{font-size:80%;vertical-align:0.65em}</style><span class="chemf nowrap"><a href="/wiki/Trihydrogen_cation#Destruction" title="Trihydrogen cation">H<span class="template-chem2-su"><span>+</span><span>3</span></span></a></span> abundance. Then, important chemical pathways leading from <sup>•</sup>HO radicals are: </p><p><sup>•</sup>HO + <sup>•</sup>O → O<sub>2</sub> + <sup>•</sup>H (1A) Neutral-neutral </p><p><sup>•</sup>HO + C<sup>+</sup> → CO<sup>+</sup> + <sup>•</sup>H (2A) Ion-neutral </p><p><sup>•</sup>HO + <sup>•</sup>N → NO + <sup>•</sup>H (3A) Neutral-neutral </p><p><sup>•</sup>HO + C → CO + <sup>•</sup>H (4A) Neutral-neutral </p><p><sup>•</sup>HO + <sup>•</sup>H → H<sub>2</sub>O + photon (5A) Neutral-neutral </p> <div class="mw-heading mw-heading4"><h4 id="Rate_constants_and_relative_rates_for_important_formation_and_destruction_mechanisms"><i>Rate constants and relative rates for important formation and destruction mechanisms</i></h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=10" title="Edit section: Rate constants and relative rates for important formation and destruction mechanisms"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Rate constants can be derived from the dataset published on the website <a rel="nofollow" class="external autonumber" href="http://udfa.net">[1]</a>. Rate constants have the form: </p><p>k(T) = alpha*(T/300)<sup>beta</sup>*exp(-gamma/T)cm<sup>3</sup>s<sup>−1</sup> </p><p>The following table has the rate constants calculated for a typical temperature in a dense cloud T=10 K. </p> <table class="wikitable" border="1"> <tbody><tr> <th>Reaction </th> <th>k (T=10 K) cm<sup>3</sup>s<sup>−1</sup> </th></tr> <tr> <td>1a </td> <td>3.29 10<sup>−6</sup> </td></tr> <tr> <td>1b </td> <td>1.41 10<sup>−7</sup> </td></tr> <tr> <td>2a </td> <td>4.71 10<sup>−7</sup> </td></tr> <tr> <td>3a </td> <td>5.0 10<sup>−11</sup> </td></tr> <tr> <td>4a </td> <td>1.26 10<sup>−6</sup> </td></tr> <tr> <td>5a </td> <td>2.82 10<sup>−6</sup> </td></tr> <tr> <td>1A </td> <td>7.7 10<sup>−10</sup> </td></tr> <tr> <td>2A </td> <td>3.5 10<sup>−11</sup> </td></tr> <tr> <td>3A </td> <td>1.38 10<sup>−10</sup> </td></tr> <tr> <td>4A </td> <td>1.0 10<sup>−10</sup> </td></tr> <tr> <td>5A </td> <td>3.33 10<sup>−14</sup> </td></tr></tbody></table> <p>Formation rates r<sub>ix</sub> can be obtained using the rate constants k(T) and the abundances of the reactants species C and D: </p><p>r<sub>ix</sub>=k(T)<sub>ix</sub>[C][D] </p><p>where [Y] represents the abundance of the specie Y. In this approach, abundances were taken from <i>The UMIST database for astrochemistry 2006</i>, and the values are relatives to the H<sub>2</sub> density. Following table shows the ratio r<sub>ix</sub>/r<sub>1a</sub> in order to get a view of the most important reactions. </p> <table class="wikitable" border="1"> <tbody><tr> <th> </th> <th>r<sub>1a</sub> </th> <th>r<sub>1b</sub> </th> <th>r<sub>2a</sub> </th> <th>r<sub>3a</sub> </th> <th>r<sub>4a</sub> </th> <th>r<sub>5a</sub> </th></tr> <tr> <td>r<sub>1a</sub> </td> <td>1.0 </td> <td>0.043 </td> <td>0.013 </td> <td>0.035 </td> <td>3.6 10<sup>−5</sup> </td> <td>0.679 </td></tr></tbody></table> <p>The results suggest that (1a) reaction is the most prominent reaction in dense clouds. It is in concordance with Harju et al. 2000. </p><p>Next table shows the results by doing the same procedure for destruction reaction: </p> <table class="wikitable" border="1"> <tbody><tr> <th> </th> <th>r<sub>1A</sub> </th> <th>r<sub>2A</sub> </th> <th>r<sub>3A</sub> </th> <th>r<sub>4A</sub> </th> <th>r<sub>5A</sub> </th></tr> <tr> <td>r<sub>1A</sub> </td> <td>1.0 </td> <td>6.14 10<sup>−3</sup> </td> <td>0.152 </td> <td>3.6 10<sup>−5</sup> </td> <td>4.29 10<sup>−3</sup> </td></tr></tbody></table> <p>Results shows that, 1A reaction is the main sink for HO in dense clouds. </p> <div class="mw-heading mw-heading3"><h3 id="Importance_of_interstellar_•HO_observations"><span id="Importance_of_interstellar_.E2.80.A2HO_observations"></span>Importance of interstellar <sup>•</sup>HO observations</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=11" title="Edit section: Importance of interstellar •HO observations"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Discoveries of the microwave spectra of a considerable number of molecules prove the existence of rather complex molecules in the interstellar clouds, and provides the possibility to study dense clouds, which are obscured by the dust they contain.<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> The <sup>•</sup>HO molecule has been observed in the interstellar medium since 1963 through its 18-cm transitions.<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> In the subsequent years <sup>•</sup>HO was observed by its rotational transitions at far infrared wavelengths, mainly in the Orion region. Because each rotational level of <sup>•</sup>HO is split in by lambda doubling, astronomers can observe a wide variety of energy states from the ground state. </p> <div class="mw-heading mw-heading4"><h4 id="•HO_as_a_tracer_of_shock_conditions"><span id=".E2.80.A2HO_as_a_tracer_of_shock_conditions"></span><sup>•</sup>HO as a tracer of shock conditions</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=12" title="Edit section: •HO as a tracer of shock conditions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Very high densities are required to thermalize the rotational transitions of <sup>•</sup>HO,<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> so it is difficult to detect far-infrared emission lines from a quiescent molecular cloud. Even at H<sub>2</sub> densities of 10<sup>6</sup> cm<sup>−3</sup>, dust must be optically thick at infrared wavelengths. But the passage of a shock wave through a molecular cloud is precisely the process which can bring the molecular gas out of equilibrium with the dust, making observations of far-infrared emission lines possible. A moderately fast shock may produce a transient raise in the <sup>•</sup>HO abundance relative to hydrogen. So, it is possible that far-infrared emission lines of <sup>•</sup>HO can be a good diagnostic of shock conditions. </p> <div class="mw-heading mw-heading4"><h4 id="In_diffuse_clouds">In diffuse clouds</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=13" title="Edit section: In diffuse clouds"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Diffuse clouds are of astronomical interest because they play a primary role in the evolution and thermodynamics of ISM. Observation of the abundant atomic hydrogen in 21 cm has shown good signal-to-noise ratio in both emission and absorption. Nevertheless, HI observations have a fundamental difficulty when are directed to low mass regions of the hydrogen nucleus, as the center part of a diffuse cloud: Thermal width of hydrogen lines are the same order as the internal velocities' structures of interest, so clouds components of various temperatures and central velocities are indistinguishable in the spectrum. Molecular lines observations in principle doesn't suffer from these problems. Unlike HI, molecules generally have <a href="/wiki/Excitation_temperature" title="Excitation temperature">excitation temperature</a> T<sub>ex</sub> << T<sub>kin</sub>, so that emission is very weak even from abundant species. CO and <sup>•</sup>HO are considered to be the most easily studied candidate molecules. CO has transitions in a region of the spectrum (wavelength < 3 mm) where there are not strong background continuum sources, but <sup>•</sup>HO has the 18 cm emission, line convenient for absorption observations.<sup id="cite_ref-DickeyCrovisier1981_16-1" class="reference"><a href="#cite_note-DickeyCrovisier1981-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> Observation studies provide the most sensitive means of detections of molecules with sub thermal excitation, and can give the opacity of the spectral line, which is a central issue to model the molecular region. </p><p>Studies based in the kinematic comparison of <sup>•</sup>HO and HI absorption lines from diffuse clouds are useful in determining their physical conditions, especially because heavier elements provide higher velocity resolution. </p> <div class="mw-heading mw-heading4"><h4 id="•HO_masers"><span id=".E2.80.A2HO_masers"></span><sup>•</sup>HO masers</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Hydroxyl_radical&action=edit&section=14" title="Edit section: •HO masers"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><sup>•</sup>HO <a href="/wiki/Maser" title="Maser">masers</a>, a type of <a href="/wiki/Astrophysical_maser" title="Astrophysical maser">astrophysical maser</a>, were the first masers to be discovered in space and have been observed in more environments than any other type of maser. </p><p>In the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a>, <sup>•</sup>HO masers are found in stellar masers (evolved stars), interstellar masers (regions of massive star formation), or in the interface between supernova remnants and molecular material. Interstellar HO masers are often observed from molecular material surrounding ultracompact <a href="/wiki/H_II_region" title="H II region">H II regions</a> (UC H II). But there are masers associated with very young stars that have yet to create UC H II regions.<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> This class of <sup>•</sup>HO masers appears to form near the edges of very dense material, places where H<sub>2</sub>O masers form, and where total densities drop rapidly, and UV radiation from young stars can dissociate the H<sub>2</sub>O molecules. So, observations of <sup>•</sup>HO masers in these regions, can be an important way to probe the distribution of the important H<sub>2</sub>O molecule in interstellar shocks at high <a href="/wiki/Spatial_resolution" title="Spatial resolution">spatial resolutions</a>. </p><p><b>Application in <a href="/wiki/Water_purification" title="Water purification">water purification</a></b> </p><p>Hydroxyl radicals also play a key role in the <a href="/wiki/Oxidative" class="mw-redirect" title="Oxidative">oxidative</a> destruction of <a href="/wiki/Persistent_organic_pollutant" title="Persistent organic pollutant">organic pollutants</a>.<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> <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=Hydroxyl_radical&action=edit&section=15" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Hydroxyl_ion_absorption" title="Hydroxyl ion absorption">Hydroxyl ion absorption</a></li> <li><a href="/wiki/Hydrogen_darkening" title="Hydrogen darkening">Hydrogen darkening</a></li></ul> <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=Hydroxyl_radical&action=edit&section=16" 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 reflist-columns-2"> <ol class="references"> <li id="cite_note-Hydroxyl_(CHEBI:29191)-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-Hydroxyl_(CHEBI:29191)_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Hydroxyl_(CHEBI:29191)_1-1"><sup><i><b>b</b></i></sup></a></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 class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29191">"Hydroxyl (CHEBI:29191)"</a>. <i>Chemical Entities of Biological Interest (ChEBI)</i>. UK: European Bioinformatics Institute.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Chemical+Entities+of+Biological+Interest+%28ChEBI%29&rft.atitle=Hydroxyl+%28CHEBI%3A29191%29&rft_id=http%3A%2F%2Fwww.ebi.ac.uk%2Fchebi%2FsearchId.do%3FchebiId%3DCHEBI%3A29191&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-P82db-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-P82db_2-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPerrin1982" class="citation book cs1">Perrin, D. D., ed. (1982) [1969]. <i>Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution</i>. <a href="/wiki/IUPAC" class="mw-redirect" title="IUPAC">IUPAC</a> Chemical Data (2nd ed.). Oxford: Pergamon (published 1984). Entry 32. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-08-029214-3" title="Special:BookSources/0-08-029214-3"><bdi>0-08-029214-3</bdi></a>. <a href="/wiki/LCCN_(identifier)" class="mw-redirect" title="LCCN (identifier)">LCCN</a> <a rel="nofollow" class="external text" href="https://lccn.loc.gov/82-16524">82-16524</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Ionisation+Constants+of+Inorganic+Acids+and+Bases+in+Aqueous+Solution&rft.place=Oxford&rft.series=IUPAC+Chemical+Data&rft.pages=Entry+32&rft.edition=2nd&rft.pub=Pergamon&rft.date=1982&rft_id=info%3Alccn%2F82-16524&rft.isbn=0-08-029214-3&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFForster,_P.V._RamaswamyP._ArtaxoT._Berntsen2007" class="citation book cs1">Forster, P.; V. Ramaswamy; P. Artaxo; T. Berntsen; R. Betts; D.W. Fahey; J. Haywood; J. Lean; D.C. Lowe; G. Myhre; J. Nganga; R. Prinn; G. Raga; M. Schulz; R. Van Dorland (2007). <a rel="nofollow" class="external text" href="http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf">"Changes in Atmospheric Constituents and in Radiative Forcing"</a> <span class="cs1-format">(PDF)</span>. In Solomon, S.; D. Qin; M. Manning; Z. Chen; M. Marquis; K.B. Averyt; M.Tignor; H.L. Miller (eds.). <i>Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change</i>. Cambridge University Press. <q>The hydroxyl free radical (OH) is the major oxidizing chemical in the atmosphere, destroying about 3.7 Gt of trace gases, including CH4 and all HFCs and HCFCs, each year (Ehhalt, 1999).</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Changes+in+Atmospheric+Constituents+and+in+Radiative+Forcing&rft.btitle=Climate+Change+2007%3A+The+Physical+Science+Basis.+Contribution+of+Working+Group+I+to+the+Fourth+Assessment+Report+of+the+Intergovernmental+Panel+on+Climate+Change&rft.pub=Cambridge+University+Press&rft.date=2007&rft.au=Forster%2C+P.&rft.au=V.+Ramaswamy&rft.au=P.+Artaxo&rft.au=T.+Berntsen&rft.au=R.+Betts&rft.au=D.W.+Fahey&rft.au=J.+Haywood&rft.au=J.+Lean&rft.au=D.C.+Lowe&rft.au=G.+Myhre&rft.au=J.+Nganga&rft.au=R.+Prinn&rft.au=G.+Raga&rft.au=M.+Schulz&rft.au=R.+Van+Dorland&rft_id=http%3A%2F%2Fwww.ipcc.ch%2Fpdf%2Fassessment-report%2Far4%2Fwg1%2Far4-wg1-chapter2.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFKincaid-ColtonWolfgang_Streit1995" class="citation journal cs1">Kincaid-Colton, Carol; Wolfgang Streit (November 1995). "The Brain's Immune System". <i>Scientific American</i>. <b>273</b> (5): <span class="nowrap">54–</span>5, <span class="nowrap">58–</span>61. <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/1995SciAm.273e..54S">1995SciAm.273e..54S</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%2Fscientificamerican1195-54">10.1038/scientificamerican1195-54</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/8966536">8966536</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Scientific+American&rft.atitle=The+Brain%27s+Immune+System&rft.volume=273&rft.issue=5&rft.pages=%3Cspan+class%3D%22nowrap%22%3E54-%3C%2Fspan%3E5%2C+%3Cspan+class%3D%22nowrap%22%3E58-%3C%2Fspan%3E61&rft.date=1995-11&rft_id=info%3Apmid%2F8966536&rft_id=info%3Adoi%2F10.1038%2Fscientificamerican1195-54&rft_id=info%3Abibcode%2F1995SciAm.273e..54S&rft.aulast=Kincaid-Colton&rft.aufirst=Carol&rft.au=Wolfgang+Streit&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFSies,_Helmut1993" class="citation journal cs1">Sies, Helmut (March 1993). "Strategies of antioxidant defense". <i>European Journal of Biochemistry</i>. <b>215</b> (2): <span class="nowrap">213–</span>219. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1111%2Fj.1432-1033.1993.tb18025.x">10.1111/j.1432-1033.1993.tb18025.x</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/7688300">7688300</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=European+Journal+of+Biochemistry&rft.atitle=Strategies+of+antioxidant+defense&rft.volume=215&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E213-%3C%2Fspan%3E219&rft.date=1993-03&rft_id=info%3Adoi%2F10.1111%2Fj.1432-1033.1993.tb18025.x&rft_id=info%3Apmid%2F7688300&rft.au=Sies%2C+Helmut&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11-6"><span class="mw-cite-backlink">^ <a href="#cite_ref-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11_6-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Reiter_RJ,_Melchiorri_D,_Sewerynek_E,_et_al._1995_1–11_6-1"><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="CITEREFReiterMelchiorriSewerynek1995" class="citation journal cs1">Reiter RJ, Melchiorri D, Sewerynek E, et al. (January 1995). "A review of the evidence supporting melatonin's role as an antioxidant". <i>J. Pineal Res</i>. <b>18</b> (1): <span class="nowrap">1–</span>11. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1111%2Fj.1600-079x.1995.tb00133.x">10.1111/j.1600-079x.1995.tb00133.x</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/7776173">7776173</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:24184946">24184946</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=J.+Pineal+Res.&rft.atitle=A+review+of+the+evidence+supporting+melatonin%27s+role+as+an+antioxidant&rft.volume=18&rft.issue=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1-%3C%2Fspan%3E11&rft.date=1995-01&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A24184946%23id-name%3DS2CID&rft_id=info%3Apmid%2F7776173&rft_id=info%3Adoi%2F10.1111%2Fj.1600-079x.1995.tb00133.x&rft.aulast=Reiter&rft.aufirst=RJ&rft.au=Melchiorri%2C+D&rft.au=Sewerynek%2C+E&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFReiterCarneiroOh1997" class="citation journal cs1">Reiter RJ, Carneiro RC, Oh CS (August 1997). "Melatonin in relation to cellular antioxidative defense mechanisms". <i>Horm. Metab. Res</i>. <b>29</b> (8): <span class="nowrap">363–</span>72. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1055%2Fs-2007-979057">10.1055/s-2007-979057</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/9288572">9288572</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:22573377">22573377</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Horm.+Metab.+Res.&rft.atitle=Melatonin+in+relation+to+cellular+antioxidative+defense+mechanisms&rft.volume=29&rft.issue=8&rft.pages=%3Cspan+class%3D%22nowrap%22%3E363-%3C%2Fspan%3E72&rft.date=1997-08&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A22573377%23id-name%3DS2CID&rft_id=info%3Apmid%2F9288572&rft_id=info%3Adoi%2F10.1055%2Fs-2007-979057&rft.aulast=Reiter&rft.aufirst=RJ&rft.au=Carneiro%2C+RC&rft.au=Oh%2C+CS&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFIsaksenS.B._Dalsøren2011" class="citation journal cs1">Isaksen, I.S.A.; S.B. Dalsøren (2011). <a rel="nofollow" class="external text" href="http://www.sciencemag.org/content/331/6013/38.short">"Getting a better estimate of an atmospheric radical"</a>. <i>Science</i>. <b>331</b> (6013): <span class="nowrap">38–</span>39. <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/2011Sci...331...38I">2011Sci...331...38I</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%2Fscience.1199773">10.1126/science.1199773</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/21212344">21212344</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:206530807">206530807</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2011-01-09</span></span>.</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=Getting+a+better+estimate+of+an+atmospheric+radical&rft.volume=331&rft.issue=6013&rft.pages=%3Cspan+class%3D%22nowrap%22%3E38-%3C%2Fspan%3E39&rft.date=2011&rft_id=info%3Adoi%2F10.1126%2Fscience.1199773&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A206530807%23id-name%3DS2CID&rft_id=info%3Apmid%2F21212344&rft_id=info%3Abibcode%2F2011Sci...331...38I&rft.aulast=Isaksen&rft.aufirst=I.S.A.&rft.au=S.B.+Dals%C3%B8ren&rft_id=http%3A%2F%2Fwww.sciencemag.org%2Fcontent%2F331%2F6013%2F38.short&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFHealHeard,_D.E.Pilling,_M.J.Whitaker,_B.J.1995" class="citation journal cs1">Heal, M.R.; Heard, D.E.; Pilling, M.J.; Whitaker, B.J. (1995). <a rel="nofollow" class="external text" href="https://doi.org/10.1175%2F1520-0469%281995%29052%3C3428%3AOTDAVO%3E2.0.CO%3B2">"On the development and validation of FAGE for local measurement of tropospheric HO and HO2"</a>. <i>Journal of the Atmospheric Sciences</i>. <b>52</b> (19): <span class="nowrap">3428–</span>3448. <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/1995JAtS...52.3428H">1995JAtS...52.3428H</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/10.1175%2F1520-0469%281995%29052%3C3428%3AOTDAVO%3E2.0.CO%3B2">10.1175/1520-0469(1995)052<3428:OTDAVO>2.0.CO;2</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/1520-0469">1520-0469</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+Atmospheric+Sciences&rft.atitle=On+the+development+and+validation+of+FAGE+for+local+measurement+of+tropospheric+HO+and+HO2&rft.volume=52&rft.issue=19&rft.pages=%3Cspan+class%3D%22nowrap%22%3E3428-%3C%2Fspan%3E3448&rft.date=1995&rft.issn=1520-0469&rft_id=info%3Adoi%2F10.1175%2F1520-0469%281995%29052%3C3428%3AOTDAVO%3E2.0.CO%3B2&rft_id=info%3Abibcode%2F1995JAtS...52.3428H&rft.aulast=Heal&rft.aufirst=M.R.&rft.au=Heard%2C+D.E.&rft.au=Pilling%2C+M.J.&rft.au=Whitaker%2C+B.J.&rft_id=https%3A%2F%2Fdoi.org%2F10.1175%252F1520-0469%25281995%2529052%253C3428%253AOTDAVO%253E2.0.CO%253B2&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFMontzkaM._KrolE._DlugokenckyB._Hall2011" class="citation journal cs1">Montzka, S.A.; M. Krol; E. Dlugokencky; B. Hall; P. Jöckel; J. Lelieveld (2011). <a rel="nofollow" class="external text" href="http://www.sciencemag.org/content/331/6013/67.abstract">"Small interannual variability of global atmospheric hydroxyl"</a>. <i>Science</i>. <b>331</b> (6013): <span class="nowrap">67–</span>69. <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/2011Sci...331...67M">2011Sci...331...67M</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%2Fscience.1197640">10.1126/science.1197640</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/21212353">21212353</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:11001130">11001130</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2011-01-09</span></span>.</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=Small+interannual+variability+of+global+atmospheric+hydroxyl&rft.volume=331&rft.issue=6013&rft.pages=%3Cspan+class%3D%22nowrap%22%3E67-%3C%2Fspan%3E69&rft.date=2011&rft_id=info%3Adoi%2F10.1126%2Fscience.1197640&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A11001130%23id-name%3DS2CID&rft_id=info%3Apmid%2F21212353&rft_id=info%3Abibcode%2F2011Sci...331...67M&rft.aulast=Montzka&rft.aufirst=S.A.&rft.au=M.+Krol&rft.au=E.+Dlugokencky&rft.au=B.+Hall&rft.au=P.+J%C3%B6ckel&rft.au=J.+Lelieveld&rft_id=http%3A%2F%2Fwww.sciencemag.org%2Fcontent%2F331%2F6013%2F67.abstract&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-DieterEwen1964-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-DieterEwen1964_11-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDieterEwen1964" class="citation journal cs1">Dieter, N. H.; Ewen, H. I. (1964). "Radio Observations of the Interstellar OH Line at 1,667 Mc/s". <i>Nature</i>. <b>201</b> (4916): <span class="nowrap">279–</span>281. <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/1964Natur.201..279D">1964Natur.201..279D</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%2F201279b0">10.1038/201279b0</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/0028-0836">0028-0836</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:4163406">4163406</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=Radio+Observations+of+the+Interstellar+OH+Line+at+1%2C667+Mc%2Fs&rft.volume=201&rft.issue=4916&rft.pages=%3Cspan+class%3D%22nowrap%22%3E279-%3C%2Fspan%3E281&rft.date=1964&rft_id=info%3Adoi%2F10.1038%2F201279b0&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4163406%23id-name%3DS2CID&rft.issn=0028-0836&rft_id=info%3Abibcode%2F1964Natur.201..279D&rft.aulast=Dieter&rft.aufirst=N.+H.&rft.au=Ewen%2C+H.+I.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-RobinsonMcGee1967-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-RobinsonMcGee1967_12-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRobinsonMcGee1967" class="citation journal cs1">Robinson, B J; McGee, R X (1967). "Oh Molecules in the Interestellar Medium". <i>Annual Review of Astronomy and Astrophysics</i>. <b>5</b> (1): <span class="nowrap">183–</span>212. <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/1967ARA&A...5..183R">1967ARA&A...5..183R</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.aa.05.090167.001151">10.1146/annurev.aa.05.090167.001151</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/0066-4146">0066-4146</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+Astronomy+and+Astrophysics&rft.atitle=Oh+Molecules+in+the+Interestellar+Medium&rft.volume=5&rft.issue=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E183-%3C%2Fspan%3E212&rft.date=1967&rft.issn=0066-4146&rft_id=info%3Adoi%2F10.1146%2Fannurev.aa.05.090167.001151&rft_id=info%3Abibcode%2F1967ARA%26A...5..183R&rft.aulast=Robinson&rft.aufirst=B+J&rft.au=McGee%2C+R+X&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-Heiles1968-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-Heiles1968_13-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHeiles1968" class="citation journal cs1">Heiles, Carl E. (1968). "Normal OH Emission and Interstellar Dust Clouds". <i>The Astrophysical Journal</i>. <b>151</b>: 919. <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/1968ApJ...151..919H">1968ApJ...151..919H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F149493">10.1086/149493</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/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Normal+OH+Emission+and+Interstellar+Dust+Clouds&rft.volume=151&rft.pages=919&rft.date=1968&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F149493&rft_id=info%3Abibcode%2F1968ApJ...151..919H&rft.aulast=Heiles&rft.aufirst=Carl+E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-RankTownes1971-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-RankTownes1971_14-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRankTownesWelch1971" class="citation journal cs1">Rank, D. M.; Townes, C. H.; Welch, W. J. (1971). "Interstellar Molecules and Dense Clouds". <i>Science</i>. <b>174</b> (4014): <span class="nowrap">1083–</span>1101. <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/1971Sci...174.1083R">1971Sci...174.1083R</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%2Fscience.174.4014.1083">10.1126/science.174.4014.1083</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/0036-8075">0036-8075</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/17779392">17779392</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:43499656">43499656</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=Interstellar+Molecules+and+Dense+Clouds&rft.volume=174&rft.issue=4014&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1083-%3C%2Fspan%3E1101&rft.date=1971&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A43499656%23id-name%3DS2CID&rft_id=info%3Abibcode%2F1971Sci...174.1083R&rft.issn=0036-8075&rft_id=info%3Adoi%2F10.1126%2Fscience.174.4014.1083&rft_id=info%3Apmid%2F17779392&rft.aulast=Rank&rft.aufirst=D.+M.&rft.au=Townes%2C+C.+H.&rft.au=Welch%2C+W.+J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-BaudWouterloot1980-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-BaudWouterloot1980_15-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBaudWouterloot1980" class="citation cs2">Baud, B.; Wouterloot, J. G. A. (1980), "OH observations of molecular complexes in Orion and Taurus", <i>Astronomy and Astrophysics</i>, <b>90</b>: 297, <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/1980A&A....90..297B">1980A&A....90..297B</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=OH+observations+of+molecular+complexes+in+Orion+and+Taurus&rft.volume=90&rft.pages=297&rft.date=1980&rft_id=info%3Abibcode%2F1980A%26A....90..297B&rft.aulast=Baud&rft.aufirst=B.&rft.au=Wouterloot%2C+J.+G.+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-DickeyCrovisier1981-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-DickeyCrovisier1981_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-DickeyCrovisier1981_16-1"><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="CITEREFDickeyCrovisierKazes1981" class="citation journal cs1">Dickey JM, Crovisier J, Kazes I (May 1981). "Emission-absorption observations of <sup>•</sup>HO in diffuse interstellar clouds". <i>Astronomy and Astrophysics</i>. <b>98</b> (2): <span class="nowrap">271–</span>285. <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/1981A&A....98..271D">1981A&A....98..271D</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=Emission-absorption+observations+of+%3Csup%3E%E2%80%A2%3C%2Fsup%3EHO+in+diffuse+interstellar+clouds&rft.volume=98&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E271-%3C%2Fspan%3E285&rft.date=1981-05&rft_id=info%3Abibcode%2F1981A%26A....98..271D&rft.aulast=Dickey&rft.aufirst=JM&rft.au=Crovisier%2C+J&rft.au=Kazes%2C+I&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-CrutcherTroland1981-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-CrutcherTroland1981_17-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCrutcherTrolandHeiles1981" class="citation journal cs1">Crutcher, R. M.; Troland, T. H.; Heiles, C. (1981). "Magnetic fields in molecular clouds - OH Zeeman observations". <i>The Astrophysical Journal</i>. <b>249</b>: 134. <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/1981ApJ...249..134C">1981ApJ...249..134C</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F159268">10.1086/159268</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/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Magnetic+fields+in+molecular+clouds+-+OH+Zeeman+observations&rft.volume=249&rft.pages=134&rft.date=1981&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F159268&rft_id=info%3Abibcode%2F1981ApJ...249..134C&rft.aulast=Crutcher&rft.aufirst=R.+M.&rft.au=Troland%2C+T.+H.&rft.au=Heiles%2C+C.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-StoreyWatson1981-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-StoreyWatson1981_18-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFStoreyWatsonTownes1981" class="citation journal cs1">Storey, J. W. V.; Watson, D. M.; Townes, C. H. (1981). "Detection of interstellar OH in the far-infrared". <i>The Astrophysical Journal</i>. <b>244</b>: L27. <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/1981ApJ...244L..27S">1981ApJ...244L..27S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F183472">10.1086/183472</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/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Detection+of+interstellar+OH+in+the+far-infrared&rft.volume=244&rft.pages=L27&rft.date=1981&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F183472&rft_id=info%3Abibcode%2F1981ApJ...244L..27S&rft.aulast=Storey&rft.aufirst=J.+W.+V.&rft.au=Watson%2C+D.+M.&rft.au=Townes%2C+C.+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-BaanHaschick1989-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-BaanHaschick1989_19-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBaanHaschickHenkel1989" class="citation journal cs1">Baan, Willem A.; Haschick, Aubrey D.; Henkel, Christian (1989). "Molecular outflows in powerful OH megamasers". <i>The Astrophysical Journal</i>. <b>346</b>: 680. <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/1989ApJ...346..680B">1989ApJ...346..680B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F168050">10.1086/168050</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/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Molecular+outflows+in+powerful+OH+megamasers&rft.volume=346&rft.pages=680&rft.date=1989&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F168050&rft_id=info%3Abibcode%2F1989ApJ...346..680B&rft.aulast=Baan&rft.aufirst=Willem+A.&rft.au=Haschick%2C+Aubrey+D.&rft.au=Henkel%2C+Christian&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-HarjuWinnberg2000-20"><span class="mw-cite-backlink">^ <a href="#cite_ref-HarjuWinnberg2000_20-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-HarjuWinnberg2000_20-1"><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="CITEREFHarjuWinnbergWouterloot2000" class="citation cs2">Harju, J.; Winnberg, A.; Wouterloot, J. G. A. (2000), "The distribution of OH in Taurus Molecular Cloud-1", <i>Astronomy and Astrophysics</i>, <b>353</b>: 1065, <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/2000A&A...353.1065H">2000A&A...353.1065H</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=The+distribution+of+OH+in+Taurus+Molecular+Cloud-1&rft.volume=353&rft.pages=1065&rft.date=2000&rft_id=info%3Abibcode%2F2000A%26A...353.1065H&rft.aulast=Harju&rft.aufirst=J.&rft.au=Winnberg%2C+A.&rft.au=Wouterloot%2C+J.+G.+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></span> </li> <li id="cite_note-FieldAdams1980-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-FieldAdams1980_21-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFieldAdamsSmith1980" class="citation cs2">Field, D.; Adams, N. G.; Smith, D. (1980), "Molecular synthesis in interstellar clouds - The radiative association reaction H + OH yields H2O + h/nu/", <i>Monthly Notices of the Royal Astronomical Society</i>, <b>192</b>: 1, <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/1980MNRAS.192....1F">1980MNRAS.192....1F</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/10.1093%2Fmnras%2F192.1.1">10.1093/mnras/192.1.1</a></span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=Molecular+synthesis+in+interstellar+clouds+-+The+radiative+association+reaction+H+%2B+OH+yields+H2O+%2B+h%2Fnu%2F&rft.volume=192&rft.pages=1&rft.date=1980&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F192.1.1&rft_id=info%3Abibcode%2F1980MNRAS.192....1F&rft.aulast=Field&rft.aufirst=D.&rft.au=Adams%2C+N.+G.&rft.au=Smith%2C+D.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFRankTownesWelch1971" class="citation journal cs1">Rank DM, Townes CH, Welch WJ (1971-12-01). <a rel="nofollow" class="external text" href="http://www.sciencemag.org/cgi/content/refs/174/4014/1083">"Interstellar Molecules and Dense Clouds"</a>. <i>Science</i>. <b>174</b> (4014): <span class="nowrap">1083–</span>1101. <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/1971Sci...174.1083R">1971Sci...174.1083R</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%2Fscience.174.4014.1083">10.1126/science.174.4014.1083</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/17779392">17779392</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:43499656">43499656</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2009-01-13</span></span>.</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=Interstellar+Molecules+and+Dense+Clouds&rft.volume=174&rft.issue=4014&rft.pages=%3Cspan+class%3D%22nowrap%22%3E1083-%3C%2Fspan%3E1101&rft.date=1971-12-01&rft_id=info%3Adoi%2F10.1126%2Fscience.174.4014.1083&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A43499656%23id-name%3DS2CID&rft_id=info%3Apmid%2F17779392&rft_id=info%3Abibcode%2F1971Sci...174.1083R&rft.aulast=Rank&rft.aufirst=DM&rft.au=Townes%2C+CH&rft.au=Welch%2C+WJ&rft_id=http%3A%2F%2Fwww.sciencemag.org%2Fcgi%2Fcontent%2Frefs%2F174%2F4014%2F1083&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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 id="CITEREFDieterEwen1964" class="citation journal cs1">Dieter NH, Ewen HI (1964-01-18). <a rel="nofollow" class="external text" href="http://www.nature.com/nature/journal/v201/n4916/abs/201279b0.html">"Radio Observations of the Interstellar HO Line at 1,667 Mc/s"</a>. <i>Nature</i>. <b>201</b> (4916): <span class="nowrap">279–</span>281. <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/1964Natur.201..279D">1964Natur.201..279D</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%2F201279b0">10.1038/201279b0</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:4163406">4163406</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2009-01-13</span></span>.</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=Radio+Observations+of+the+Interstellar+HO+Line+at+1%2C667+Mc%2Fs&rft.volume=201&rft.issue=4916&rft.pages=%3Cspan+class%3D%22nowrap%22%3E279-%3C%2Fspan%3E281&rft.date=1964-01-18&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A4163406%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F201279b0&rft_id=info%3Abibcode%2F1964Natur.201..279D&rft.aulast=Dieter&rft.aufirst=NH&rft.au=Ewen%2C+HI&rft_id=http%3A%2F%2Fwww.nature.com%2Fnature%2Fjournal%2Fv201%2Fn4916%2Fabs%2F201279b0.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFStoreyWatsonTownes1981" class="citation journal cs1">Storey JW, Watson DM, Townes CH (1981-02-15). "Detection of interstellar HO in the far-infrared". <i>Astrophysical Journal, Part 2 - Letters to the Editor</i>. <b>244</b>: <span class="nowrap">L27 –</span> <span class="nowrap">L30</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/1981ApJ...244L..27S">1981ApJ...244L..27S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F183472">10.1086/183472</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astrophysical+Journal%2C+Part+2+-+Letters+to+the+Editor&rft.atitle=Detection+of+interstellar+HO+in+the+far-infrared&rft.volume=244&rft.pages=%3Cspan+class%3D%22nowrap%22%3EL27+-%3C%2Fspan%3E+%3Cspan+class%3D%22nowrap%22%3EL30%3C%2Fspan%3E&rft.date=1981-02-15&rft_id=info%3Adoi%2F10.1086%2F183472&rft_id=info%3Abibcode%2F1981ApJ...244L..27S&rft.aulast=Storey&rft.aufirst=JW&rft.au=Watson%2C+DM&rft.au=Townes%2C+CH&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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="CITEREFArgonReidMenten2003" class="citation journal cs1">Argon AL, Reid MJ, Menten KM (August 2003). "A class of interstellar <sup>•</sup>HO masers associated with protostellar outflows". <i>The Astrophysical Journal</i>. <b>593</b> (2): <span class="nowrap">925–</span>930. <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/astro-ph/0304565">astro-ph/0304565</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/2003ApJ...593..925A">2003ApJ...593..925A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F376592">10.1086/376592</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=A+class+of+interstellar+%3Csup%3E%E2%80%A2%3C%2Fsup%3EHO+masers+associated+with+protostellar+outflows&rft.volume=593&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E925-%3C%2Fspan%3E930&rft.date=2003-08&rft_id=info%3Aarxiv%2Fastro-ph%2F0304565&rft_id=info%3Adoi%2F10.1086%2F376592&rft_id=info%3Abibcode%2F2003ApJ...593..925A&rft.aulast=Argon&rft.aufirst=AL&rft.au=Reid%2C+MJ&rft.au=Menten%2C+KM&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" 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"><a rel="nofollow" class="external text" href="https://theconversation.com/la-materia-de-la-que-estan-hechos-los-rayos-puede-ayudarnos-a-depurar-el-agua-y-a-afrontar-la-sequia-225516">The Conversation (Spanish Edition): The material that rays are made of can help us purify water and deal with drought Published: March 21, 2024 22:42 CET</a></span> </li> </ol></div> <style data-mw-deduplicate="TemplateStyles:r1239549316">.mw-parser-output .refbegin{margin-bottom:0.5em}.mw-parser-output .refbegin-hanging-indents>ul{margin-left:0}.mw-parser-output .refbegin-hanging-indents>ul>li{margin-left:0;padding-left:3.2em;text-indent:-3.2em}.mw-parser-output .refbegin-hanging-indents ul,.mw-parser-output .refbegin-hanging-indents ul li{list-style:none}@media(max-width:720px){.mw-parser-output .refbegin-hanging-indents>ul>li{padding-left:1.6em;text-indent:-1.6em}}.mw-parser-output .refbegin-columns{margin-top:0.3em}.mw-parser-output .refbegin-columns ul{margin-top:0}.mw-parser-output .refbegin-columns li{page-break-inside:avoid;break-inside:avoid-column}@media screen{.mw-parser-output .refbegin{font-size:90%}}</style><div class="refbegin" style=""> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDownesBlunt1879" class="citation journal cs1">Downes A, Blunt TP (1879). "The effect of sunlight upon hydrogen peroxide". <i>Nature</i>. <b>20</b> (517): 521. <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/1879Natur..20Q.521.">1879Natur..20Q.521.</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%2F020521a0">10.1038/020521a0</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=The+effect+of+sunlight+upon+hydrogen+peroxide&rft.volume=20&rft.issue=517&rft.pages=521&rft.date=1879&rft_id=info%3Adoi%2F10.1038%2F020521a0&rft_id=info%3Abibcode%2F1879Natur..20Q.521.&rft.aulast=Downes&rft.aufirst=A&rft.au=Blunt%2C+TP&rfr_id=info%3Asid%2Fen.wikipedia.org%3AHydroxyl+radical" class="Z3988"></span></li></ul> </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=Hydroxyl_radical&action=edit&section=17" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.physorg.com/news130065276.html">Hydroxyl found in atmosphere of Venus.</a></li> <li><a rel="nofollow" class="external text" href="http://cires.colorado.edu/jimenez/AtmChem/">University lecture notes from the University of Colorado on Atmospheric Chemistry.</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="Molecules_detected_in_outer_space800" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed 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:Molecules_detected_in_outer_space" title="Template:Molecules detected in outer space"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Molecules_detected_in_outer_space" title="Template talk:Molecules detected in outer space"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Molecules_detected_in_outer_space" title="Special:EditPage/Template:Molecules detected in outer space"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Molecules_detected_in_outer_space800" style="font-size:114%;margin:0 4em"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules" title="List of interstellar and circumstellar molecules">Molecules detected in outer space</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Molecule" title="Molecule">Molecules</a></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 navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Diatomic_molecule" title="Diatomic molecule">Diatomic</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/Aluminium_monochloride" title="Aluminium monochloride">Aluminium monochloride</a></li> <li><a href="/wiki/Aluminium_monofluoride" title="Aluminium monofluoride">Aluminium monofluoride</a></li> <li><a href="/wiki/Aluminium(II)_oxide" title="Aluminium(II) oxide">Aluminium(II) oxide</a></li> <li><a href="/wiki/Argonium" title="Argonium">Argonium</a></li> <li><a href="/wiki/Carbon_cation" class="mw-redirect" title="Carbon cation">Carbon cation</a></li> <li><a href="/wiki/Carbon_monophosphide" title="Carbon monophosphide">Carbon monophosphide</a></li> <li><a href="/wiki/Carbon_monosulfide" title="Carbon monosulfide">Carbon monosulfide</a></li> <li><a href="/wiki/Carbon_monoxide" title="Carbon monoxide">Carbon monoxide</a></li> <li><a href="/wiki/Cyano_radical" title="Cyano radical">Cyano radical</a></li> <li><a href="/wiki/Diatomic_carbon" title="Diatomic carbon">Diatomic carbon</a></li> <li><a href="/w/index.php?title=Fluoromethylidynium&action=edit&redlink=1" class="new" title="Fluoromethylidynium (page does not exist)">Fluoromethylidynium</a></li> <li><a href="/wiki/Helium_hydride_ion" title="Helium hydride ion">Helium hydride ion</a></li> <li><a href="/wiki/Hydrogen_chloride" title="Hydrogen chloride">Hydrogen chloride</a></li> <li><a href="/wiki/Hydrogen_fluoride" title="Hydrogen fluoride">Hydrogen fluoride</a></li> <li><a href="/wiki/Hydrogen" title="Hydrogen">Hydrogen</a> (molecular)</li> <li><a class="mw-selflink selflink">Hydroxyl radical</a></li> <li><a href="/wiki/Imidogen" title="Imidogen">Imidogen</a></li> <li><a href="/wiki/Iron(II)_oxide" title="Iron(II) oxide">Iron(II) oxide</a></li> <li><a href="/wiki/Magnesium_monohydride" title="Magnesium monohydride">Magnesium monohydride</a></li> <li><a href="/wiki/Methylidyne_radical" title="Methylidyne radical">Methylidyne radical</a></li> <li><a href="/wiki/Nitric_oxide" title="Nitric oxide">Nitric oxide</a></li> <li><a href="/wiki/Nitrogen" title="Nitrogen">Nitrogen</a> (molecular)</li> <li><a href="/wiki/Oxygen" title="Oxygen">Oxygen</a> (molecular)</li> <li><a href="/wiki/Phosphorus_monoxide" title="Phosphorus monoxide">Phosphorus monoxide</a></li> <li><a href="/wiki/Phosphorus_mononitride" title="Phosphorus mononitride">Phosphorus mononitride</a></li> <li><a href="/wiki/Potassium_chloride" title="Potassium chloride">Potassium chloride</a></li> <li><a href="/wiki/Silicon_carbide" title="Silicon carbide">Silicon carbide</a></li> <li><a href="/wiki/Silicon_monoxide" title="Silicon monoxide">Silicon monoxide</a></li> <li><a href="/wiki/Silicon_monosulfide" title="Silicon monosulfide">Silicon monosulfide</a></li> <li><a href="/wiki/Sodium_chloride" title="Sodium chloride">Sodium chloride</a></li> <li><a href="/wiki/Sodium_iodide" title="Sodium iodide">Sodium iodide</a></li> <li><a href="/wiki/Sulfanyl" title="Sulfanyl">Sulfanyl</a></li> <li><a href="/wiki/Sulfur_mononitride" title="Sulfur mononitride">Sulfur mononitride</a></li> <li><a href="/wiki/Sulfur_monoxide" title="Sulfur monoxide">Sulfur monoxide</a></li> <li><a href="/wiki/Titanium(II)_oxide" title="Titanium(II) oxide">Titanium(II) oxide</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="9" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/Nitrous_oxide" title="Nitrous oxide"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/93/Nitrous-oxide-3D-balls.png/60px-Nitrous-oxide-3D-balls.png" decoding="async" width="60" height="24" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/93/Nitrous-oxide-3D-balls.png/90px-Nitrous-oxide-3D-balls.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/93/Nitrous-oxide-3D-balls.png/120px-Nitrous-oxide-3D-balls.png 2x" data-file-width="1100" data-file-height="441" /></a></span> <br /><br /><br /><br /> <span typeof="mw:File"><a href="/wiki/Ethanol" title="Ethanol"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Ethanol-3D-balls.png/60px-Ethanol-3D-balls.png" decoding="async" width="60" height="41" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Ethanol-3D-balls.png/90px-Ethanol-3D-balls.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Ethanol-3D-balls.png/120px-Ethanol-3D-balls.png 2x" data-file-width="1100" data-file-height="754" /></a></span> <br /><br /><br /><br /> <span typeof="mw:File"><a href="/wiki/Buckminsterfullerene" title="Buckminsterfullerene"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Buckminsterfullerene-perspective-3D-balls.png/60px-Buckminsterfullerene-perspective-3D-balls.png" decoding="async" width="60" height="63" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Buckminsterfullerene-perspective-3D-balls.png/90px-Buckminsterfullerene-perspective-3D-balls.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Buckminsterfullerene-perspective-3D-balls.png/120px-Buckminsterfullerene-perspective-3D-balls.png 2x" data-file-width="1056" data-file-height="1100" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Triatomic_molecule" title="Triatomic molecule">Triatomic</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/Aluminium(I)_hydroxide" class="mw-redirect" title="Aluminium(I) hydroxide">Aluminium(I) hydroxide</a></li> <li><a href="/w/index.php?title=Aluminium_isocyanide&action=edit&redlink=1" class="new" title="Aluminium isocyanide (page does not exist)">Aluminium isocyanide</a></li> <li><a href="/wiki/Amino_radical" title="Amino radical">Amino radical</a></li> <li><a href="/wiki/Carbon_dioxide" title="Carbon dioxide">Carbon dioxide</a></li> <li><a href="/wiki/Carbonyl_sulfide" title="Carbonyl sulfide">Carbonyl sulfide</a></li> <li><a href="/w/index.php?title=CCP_radical&action=edit&redlink=1" class="new" title="CCP radical (page does not exist)">CCP radical</a></li> <li><a href="/wiki/Halonium_ion" title="Halonium ion">Chloronium</a></li> <li><a href="/wiki/Diazenylium" title="Diazenylium">Diazenylium</a></li> <li><a href="/wiki/Dicarbon_monoxide" title="Dicarbon monoxide">Dicarbon monoxide</a></li> <li><a href="/w/index.php?title=Disilicon_carbide&action=edit&redlink=1" class="new" title="Disilicon carbide (page does not exist)">Disilicon carbide</a></li> <li><a href="/wiki/Ethynyl_radical" title="Ethynyl radical">Ethynyl radical</a></li> <li><a href="/w/index.php?title=Formyl_radical&action=edit&redlink=1" class="new" title="Formyl radical (page does not exist)">Formyl radical</a></li> <li><a href="/wiki/Hydrogen_cyanide" title="Hydrogen cyanide">Hydrogen cyanide</a> (HCN)</li> <li><a href="/wiki/Hydrogen_isocyanide" title="Hydrogen isocyanide">Hydrogen isocyanide</a> (HNC)</li> <li><a href="/wiki/Hydrogen_sulfide" title="Hydrogen sulfide">Hydrogen sulfide</a></li> <li><a href="/wiki/Hydroperoxyl" title="Hydroperoxyl">Hydroperoxyl</a></li> <li><a href="/wiki/Iron(II)_cyanide" title="Iron(II) cyanide">Iron cyanide</a></li> <li><a href="/w/index.php?title=Isoformyl&action=edit&redlink=1" class="new" title="Isoformyl (page does not exist)">Isoformyl</a></li> <li><a href="/wiki/Magnesium_cyanide" title="Magnesium cyanide">Magnesium cyanide</a></li> <li><a href="/w/index.php?title=Magnesium_isocyanide&action=edit&redlink=1" class="new" title="Magnesium isocyanide (page does not exist)">Magnesium isocyanide</a></li> <li><a href="/wiki/Methylene_(compound)" title="Methylene (compound)">Methylene</a></li> <li><a href="/wiki/Methylidynephosphane" title="Methylidynephosphane">Methylidynephosphane</a></li> <li><a href="/wiki/Diazenylium" title="Diazenylium">N<sub>2</sub>H<sup>+</sup></a></li> <li><a href="/wiki/Nitrous_oxide" title="Nitrous oxide">Nitrous oxide</a></li> <li><a href="/wiki/Nitroxyl" title="Nitroxyl">Nitroxyl</a></li> <li><a href="/wiki/Ozone" title="Ozone">Ozone</a></li> <li><a href="/wiki/Potassium_cyanide" title="Potassium cyanide">Potassium cyanide</a></li> <li><a href="/wiki/Sodium_cyanide" title="Sodium cyanide">Sodium cyanide</a></li> <li><a href="/wiki/Sodium_hydroxide" title="Sodium hydroxide">Sodium hydroxide</a></li> <li><a href="/w/index.php?title=Silicon_carbonitride&action=edit&redlink=1" class="new" title="Silicon carbonitride (page does not exist)">Silicon carbonitride</a></li> <li><a href="/w/index.php?title=C-Silicon_dicarbide&action=edit&redlink=1" class="new" title="C-Silicon dicarbide (page does not exist)">c-Silicon dicarbide</a></li> <li><a href="/w/index.php?title=SiNC&action=edit&redlink=1" class="new" title="SiNC (page does not exist)">SiNC</a></li> <li><a href="/wiki/Sulfur_dioxide" title="Sulfur dioxide">Sulfur dioxide</a></li> <li><a href="/w/index.php?title=Thioformyl&action=edit&redlink=1" class="new" title="Thioformyl (page does not exist)">Thioformyl</a></li> <li><a href="/wiki/Thioxoethenylidene" title="Thioxoethenylidene">Thioxoethenylidene</a></li> <li><a href="/wiki/Titanium_dioxide" title="Titanium dioxide">Titanium dioxide</a></li> <li><a href="/wiki/Tricarbon" title="Tricarbon">Tricarbon</a></li> <li><a href="/wiki/Trihydrogen_cation" title="Trihydrogen cation">Trihydrogen cation</a></li> <li><a href="/wiki/Water" title="Water">Water</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Four<br />atoms</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/Acetylene" title="Acetylene">Acetylene</a></li> <li><a href="/wiki/Ammonia" title="Ammonia">Ammonia</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Cyanoethynyl</a></li> <li><a href="/wiki/Interstellar_formaldehyde" title="Interstellar formaldehyde">Formaldehyde</a></li> <li><a href="/wiki/Fulminic_acid" title="Fulminic acid">Fulminic acid</a></li> <li><a href="/w/index.php?title=HCCN&action=edit&redlink=1" class="new" title="HCCN (page does not exist)">HCCN</a></li> <li><a href="/wiki/Hydrogen_peroxide" title="Hydrogen peroxide">Hydrogen peroxide</a></li> <li><a href="/w/index.php?title=Hydromagnesium_isocyanide&action=edit&redlink=1" class="new" title="Hydromagnesium isocyanide (page does not exist)">Hydromagnesium isocyanide</a></li> <li><a href="/wiki/Isocyanic_acid" title="Isocyanic acid">Isocyanic acid</a></li> <li><a href="/wiki/Thiocyanic_acid" title="Thiocyanic acid">Isothiocyanic acid</a></li> <li><a href="/w/index.php?title=Ketenyl&action=edit&redlink=1" class="new" title="Ketenyl (page does not exist)">Ketenyl</a></li> <li><a href="/wiki/Methyl_cation" class="mw-redirect" title="Methyl cation">Methyl cation</a></li> <li><a href="/wiki/Methyl_radical" title="Methyl radical">Methyl radical</a></li> <li><a href="/w/index.php?title=Methylene_amidogen&action=edit&redlink=1" class="new" title="Methylene amidogen (page does not exist)">Methylene amidogen</a></li> <li><a href="/wiki/Propynylidyne" title="Propynylidyne">Propynylidyne</a></li> <li><a href="/w/index.php?title=Protonated_carbon_dioxide&action=edit&redlink=1" class="new" title="Protonated carbon dioxide (page does not exist)">Protonated carbon dioxide</a></li> <li><a href="/wiki/Protonated_hydrogen_cyanide" title="Protonated hydrogen cyanide">Protonated hydrogen cyanide</a></li> <li><a href="/w/index.php?title=Silicon_tricarbide&action=edit&redlink=1" class="new" title="Silicon tricarbide (page does not exist)">Silicon tricarbide</a></li> <li><a href="/wiki/Thiocyanic_acid" title="Thiocyanic acid">Thiocyanic acid</a></li> <li><a href="/wiki/Thioformaldehyde" title="Thioformaldehyde">Thioformaldehyde</a></li> <li><a href="/wiki/Tricarbon_monosulfide" title="Tricarbon monosulfide">Tricarbon monosulfide</a></li> <li><a href="/wiki/Tricarbon_monoxide" title="Tricarbon monoxide">Tricarbon monoxide</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Five<br />atoms</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/Ammonium" title="Ammonium">Ammonium</a> ion</li> <li><a href="/wiki/Polyyne" title="Polyyne">Butadiynyl</a></li> <li><a href="/wiki/Carbodiimide" title="Carbodiimide">Carbodiimide</a></li> <li><a href="/wiki/Cyanamide" title="Cyanamide">Cyanamide</a></li> <li><a href="/wiki/Cyanoacetylene" title="Cyanoacetylene">Cyanoacetylene</a></li> <li><a href="/w/index.php?title=Cyanoformaldehyde&action=edit&redlink=1" class="new" title="Cyanoformaldehyde (page does not exist)">Cyanoformaldehyde</a></li> <li><a href="/wiki/Cyanomethyl" title="Cyanomethyl">Cyanomethyl</a></li> <li><a href="/wiki/Cyclopropenylidene" title="Cyclopropenylidene">Cyclopropenylidene</a></li> <li><a href="/wiki/Formic_acid" title="Formic acid">Formic acid</a></li> <li><a href="/w/index.php?title=Isocyanoacetylene&action=edit&redlink=1" class="new" title="Isocyanoacetylene (page does not exist)">Isocyanoacetylene</a></li> <li><a href="/wiki/Ketene" title="Ketene">Ketene</a></li> <li><a href="/wiki/Methane" title="Methane">Methane</a></li> <li><a href="/wiki/Methoxy" class="mw-redirect" title="Methoxy">Methoxy radical</a></li> <li><a href="/w/index.php?title=Methylenimine&action=edit&redlink=1" class="new" title="Methylenimine (page does not exist)">Methylenimine</a></li> <li><a href="/w/index.php?title=Propadienylidene&action=edit&redlink=1" class="new" title="Propadienylidene (page does not exist)">Propadienylidene</a></li> <li><a href="/w/index.php?title=Protonated_formaldehyde&action=edit&redlink=1" class="new" title="Protonated formaldehyde (page does not exist)">Protonated formaldehyde</a></li> <li><a href="/wiki/Silane" title="Silane">Silane</a></li> <li><a href="/w/index.php?title=Silicon-carbide_cluster&action=edit&redlink=1" class="new" title="Silicon-carbide cluster (page does not exist)">Silicon-carbide cluster</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Six<br />atoms</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/Acetonitrile" title="Acetonitrile">Acetonitrile</a></li> <li><a href="/w/index.php?title=Cyanobutadiynyl_radical&action=edit&redlink=1" class="new" title="Cyanobutadiynyl radical (page does not exist)">Cyanobutadiynyl radical</a></li> <li><a href="/wiki/Cyclopropenone" title="Cyclopropenone">Cyclopropenone</a></li> <li><a href="/wiki/Diacetylene" title="Diacetylene">Diacetylene</a></li> <li><a href="/w/index.php?title=E-Cyanomethanimine&action=edit&redlink=1" class="new" title="E-Cyanomethanimine (page does not exist)">E-Cyanomethanimine</a></li> <li><a href="/wiki/Ethylene" title="Ethylene">Ethylene</a></li> <li><a href="/wiki/Formamide" title="Formamide">Formamide</a></li> <li><a href="/w/index.php?title=HC4N&action=edit&redlink=1" class="new" title="HC4N (page does not exist)">HC<sub>4</sub>N</a></li> <li><a href="/wiki/Ketenimine" class="mw-redirect" title="Ketenimine">Ketenimine</a></li> <li><a href="/wiki/Methanethiol" title="Methanethiol">Methanethiol</a></li> <li><a href="/wiki/Methanol" title="Methanol">Methanol</a></li> <li><a href="/wiki/Methyl_isocyanide" title="Methyl isocyanide">Methyl isocyanide</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Pentynylidyne</a></li> <li><a href="/wiki/Propynal" class="mw-redirect" title="Propynal">Propynal</a></li> <li><a href="/w/index.php?title=Protonated_cyanoacetylene&action=edit&redlink=1" class="new" title="Protonated cyanoacetylene (page does not exist)">Protonated cyanoacetylene</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Seven<br />atoms</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/Acetaldehyde" title="Acetaldehyde">Acetaldehyde</a></li> <li><a href="/wiki/Acrylonitrile" title="Acrylonitrile">Acrylonitrile</a> <ul><li><a href="/wiki/Vinyl_cyanide" class="mw-redirect" title="Vinyl cyanide">Vinyl cyanide</a></li></ul></li> <li><a href="/wiki/Cyanopolyyne" title="Cyanopolyyne">Cyanodiacetylene</a></li> <li><a href="/wiki/Ethylene_oxide" title="Ethylene oxide">Ethylene oxide</a></li> <li><a href="/wiki/Glycolonitrile" title="Glycolonitrile">Glycolonitrile</a></li> <li><a href="/wiki/Hexatriynyl_radical" title="Hexatriynyl radical">Hexatriynyl radical</a></li> <li><a href="/wiki/Methyl_isocyanate" title="Methyl isocyanate">Methyl isocyanate</a></li> <li><a href="/wiki/Methylamine" title="Methylamine">Methylamine</a></li> <li><a href="/wiki/Propyne" title="Propyne">Propyne</a></li> <li><a href="/wiki/Vinyl_alcohol" title="Vinyl alcohol">Vinyl alcohol</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Eight<br />atoms</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/Acetic_acid" title="Acetic acid">Acetic acid</a></li> <li><a href="/wiki/Acrolein" title="Acrolein">Acrolein</a></li> <li><a href="/wiki/Aminoacetonitrile" title="Aminoacetonitrile">Aminoacetonitrile</a></li> <li><a href="/w/index.php?title=Cyanoallene&action=edit&redlink=1" class="new" title="Cyanoallene (page does not exist)">Cyanoallene</a></li> <li><a href="/wiki/Ethanimine" title="Ethanimine">Ethanimine</a></li> <li><a href="/wiki/Glycolaldehyde" title="Glycolaldehyde">Glycolaldehyde</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Hexapentaenylidene</a></li> <li><a href="/wiki/Methyl_formate" title="Methyl formate">Methyl formate</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Methylcyanoacetylene</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Nine<br />atoms</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/Acetamide" title="Acetamide">Acetamide</a></li> <li><a href="/wiki/Cyanopolyyne" title="Cyanopolyyne">Cyanohexatriyne</a></li> <li><a href="/wiki/Dimethyl_ether" title="Dimethyl ether">Dimethyl ether</a></li> <li><a href="/wiki/Ethanethiol" title="Ethanethiol">Ethanethiol</a></li> <li><a href="/wiki/Ethanol" title="Ethanol">Ethanol</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Methyldiacetylene</a></li> <li><a href="/wiki/N-Methylformamide" title="N-Methylformamide">N-Methylformamide</a></li> <li><a href="/wiki/Octatetraynyl_radical" title="Octatetraynyl radical">Octatetraynyl radical</a></li> <li><a href="/wiki/Propene" class="mw-redirect" title="Propene">Propene</a></li> <li><a href="/wiki/Propionitrile" title="Propionitrile">Propionitrile</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Ten<br />atoms<br />or more</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/Acetone" title="Acetone">Acetone</a></li> <li><a href="/wiki/Benzene" title="Benzene">Benzene</a></li> <li><a href="/wiki/Benzonitrile" title="Benzonitrile">Benzonitrile</a></li> <li><a href="/wiki/Buckminsterfullerene" title="Buckminsterfullerene">Buckminsterfullerene</a> (C<sub>60</sub>, C<sub>60</sub><sup>+</sup>, fullerene, buckyball)</li> <li><a href="/wiki/Butyronitrile" title="Butyronitrile">Butyronitrile</a></li> <li><a href="/wiki/C70_fullerene" title="C70 fullerene">C<sub>70</sub> fullerene</a></li> <li><a href="/wiki/Cyanopolyyne" title="Cyanopolyyne">Cyanodecapentayne</a></li> <li><a href="/wiki/Ethyl_formate" title="Ethyl formate">Ethyl formate</a></li> <li><a href="/wiki/Ethylene_glycol" title="Ethylene glycol">Ethylene glycol</a></li> <li><a href="/w/index.php?title=Heptatrienyl_radical&action=edit&redlink=1" class="new" title="Heptatrienyl radical (page does not exist)">Heptatrienyl radical</a></li> <li><a href="/wiki/Methyl_acetate" title="Methyl acetate">Methyl acetate</a></li> <li><a href="/wiki/Cyanopolyyne" title="Cyanopolyyne">Methyl-cyano-diacetylene</a></li> <li><a href="/wiki/Polyyne" title="Polyyne">Methyltriacetylene</a></li> <li><a href="/wiki/Propionaldehyde" title="Propionaldehyde">Propionaldehyde</a></li> <li><a href="/wiki/Pyrimidine" title="Pyrimidine">Pyrimidine</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Deuterium" title="Deuterium">Deuterated</a><br />molecules</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/Ammonia" title="Ammonia">Ammonia</a></li> <li><a href="/wiki/Ammonium" title="Ammonium">Ammonium</a> ion</li> <li><a href="/wiki/Formaldehyde" title="Formaldehyde">Formaldehyde</a></li> <li><a href="/wiki/Interstellar_formaldehyde#Interstellar_reactions" title="Interstellar formaldehyde">Formyl radical</a></li> <li><a href="/wiki/Heavy_water" title="Heavy water">Heavy water</a></li> <li><a href="/wiki/Hydrogen_cyanide" title="Hydrogen cyanide">Hydrogen cyanide</a></li> <li><a href="/wiki/Hydrogen_deuteride" title="Hydrogen deuteride">Hydrogen deuteride</a></li> <li><a href="/wiki/Hydrogen_isocyanide" title="Hydrogen isocyanide">Hydrogen isocyanide</a></li> <li><a href="/wiki/Diazenylium" title="Diazenylium">N<sub>2</sub>D<sup>+</sup></a></li> <li><a href="/wiki/Propyne" title="Propyne">Propyne</a></li> <li><a href="/wiki/Trihydrogen_cation" title="Trihydrogen cation">Trihydrogen cation</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#Molecules" title="List of interstellar and circumstellar molecules">Unconfirmed</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/Anthracene" title="Anthracene">Anthracene</a></li> <li><a href="/wiki/Dihydroxyacetone" title="Dihydroxyacetone">Dihydroxyacetone</a></li> <li><a href="/wiki/Glycine" title="Glycine">Glycine</a></li> <li><a href="/wiki/Graphene" title="Graphene">Graphene</a></li> <li><a href="/w/index.php?title=H2NCO%2B&action=edit&redlink=1" class="new" title="H2NCO+ (page does not exist)">H<sub>2</sub>NCO<sup>+</sup></a></li> <li><a href="/wiki/Hemolithin" title="Hemolithin">Hemolithin</a></li> <li><a href="/wiki/Carbon" title="Carbon">Linear C<sub>5</sub></a></li> <li><a href="/wiki/Methoxyethane" title="Methoxyethane">Methoxyethane</a></li> <li><a href="/wiki/Naphthalene" title="Naphthalene">Naphthalene cation</a></li> <li><a href="/wiki/Phosphine" title="Phosphine">Phosphine</a></li> <li><a href="/wiki/Pyrene" title="Pyrene">Pyrene</a></li> <li><a href="/wiki/Silylidyne" title="Silylidyne">Silylidyne</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_interstellar_and_circumstellar_molecules#See_also" title="List of interstellar and circumstellar molecules">Related</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/Abiogenesis" title="Abiogenesis">Abiogenesis</a></li> <li><a href="/wiki/Astrobiology" title="Astrobiology">Astrobiology</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/Chemical_formula" title="Chemical formula">Chemical formula</a></li> <li><a href="/wiki/Circumstellar_dust" title="Circumstellar dust">Circumstellar dust</a></li> <li><a href="/wiki/Circumstellar_envelope" title="Circumstellar envelope">Circumstellar envelope</a></li> <li><a href="/wiki/Cosmic_dust" title="Cosmic dust">Cosmic dust</a></li> <li><a href="/wiki/Cosmic_ray" title="Cosmic ray">Cosmic ray</a></li> <li><a href="/wiki/Cosmochemistry" title="Cosmochemistry">Cosmochemistry</a></li> <li><a href="/wiki/Diffuse_interstellar_band" class="mw-redirect" title="Diffuse interstellar band">Diffuse interstellar band</a></li> <li><a href="/wiki/Earliest_known_life_forms" title="Earliest known life forms">Earliest known life forms</a></li> <li><a href="/wiki/Extraterrestrial_life" title="Extraterrestrial life">Extraterrestrial life</a></li> <li><a href="/wiki/Extraterrestrial_liquid_water" title="Extraterrestrial liquid water">Extraterrestrial liquid water</a></li> <li><a href="/wiki/Forbidden_mechanism" title="Forbidden mechanism">Forbidden mechanism</a></li> <li><a href="/wiki/Homochirality" title="Homochirality">Homochirality</a></li> <li><a href="/wiki/Intergalactic_dust" title="Intergalactic dust">Intergalactic dust</a></li> <li><a href="/wiki/Interplanetary_medium" title="Interplanetary medium">Interplanetary medium</a></li> <li><a href="/wiki/Interstellar_medium" title="Interstellar medium">Interstellar medium</a></li> <li><a href="/wiki/Iron%E2%80%93sulfur_world_theory" class="mw-redirect" title="Iron–sulfur world theory">Iron–sulfur world theory</a></li> <li><a href="/wiki/Kerogen" title="Kerogen">Kerogen</a></li> <li><a href="/wiki/Molecules_in_stars" title="Molecules in stars">Molecules in stars</a></li> <li><a href="/wiki/Nexus_for_Exoplanet_System_Science" title="Nexus for Exoplanet System Science">Nexus for Exoplanet System Science</a></li> <li><a href="/wiki/Organic_compound" title="Organic compound">Organic compound</a></li> <li><a href="/wiki/Outer_space" title="Outer space">Outer space</a></li> <li><a href="/wiki/PAH_world_hypothesis" title="PAH world hypothesis">PAH world hypothesis</a></li> <li><a href="/wiki/Photodissociation_region" title="Photodissociation region">Photodissociation region</a></li> <li><a href="/wiki/Polycyclic_aromatic_hydrocarbon" title="Polycyclic aromatic hydrocarbon">Polycyclic aromatic hydrocarbon</a> (PAH)</li> <li><a href="/wiki/Pseudo-panspermia" title="Pseudo-panspermia">Pseudo-panspermia</a></li> <li><a href="/wiki/RNA_world_hypothesis" class="mw-redirect" title="RNA world hypothesis">RNA world hypothesis</a></li> <li><a href="/wiki/Spectroscopy" title="Spectroscopy">Spectroscopy</a></li> <li><a href="/wiki/Tholin" title="Tholin">Tholin</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="font-weight: bold;"><div> <ul><li><b><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> <a href="/wiki/Category:Astrochemistry" title="Category:Astrochemistry">Category:Astrochemistry</a></b></li> <li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/16px-Earth-moon.jpg" decoding="async" width="16" height="13" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/24px-Earth-moon.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/32px-Earth-moon.jpg 2x" data-file-width="3000" data-file-height="2400" /></span></span> </span><a href="/wiki/Portal:Outer_space" title="Portal:Outer space">Outer space portal</a></li> <li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/16px-Crab_Nebula.jpg" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/24px-Crab_Nebula.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/32px-Crab_Nebula.jpg 2x" data-file-width="3864" data-file-height="3864" /></span></span> </span><a href="/wiki/Portal:Astronomy" title="Portal:Astronomy">Astronomy portal</a></li> <li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Papapishu-Lab-icon-6.svg/16px-Papapishu-Lab-icon-6.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Papapishu-Lab-icon-6.svg/24px-Papapishu-Lab-icon-6.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Papapishu-Lab-icon-6.svg/32px-Papapishu-Lab-icon-6.svg.png 2x" data-file-width="512" data-file-height="512" /></span></span> </span><a href="/wiki/Portal:Chemistry" title="Portal:Chemistry">Chemistry portal</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" 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=Hydroxyl_radical&oldid=1268592987">https://en.wikipedia.org/w/index.php?title=Hydroxyl_radical&oldid=1268592987</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">Categories</a>: <ul><li><a href="/wiki/Category:Alcohols" title="Category:Alcohols">Alcohols</a></li><li><a href="/wiki/Category:Biological_processes" title="Category:Biological processes">Biological processes</a></li><li><a href="/wiki/Category:Environmental_chemistry" title="Category:Environmental chemistry">Environmental chemistry</a></li><li><a href="/wiki/Category:Free_radicals" title="Category:Free radicals">Free radicals</a></li><li><a href="/wiki/Category:Hydroxides" title="Category:Hydroxides">Hydroxides</a></li><li><a href="/wiki/Category:Reactive_intermediates" title="Category:Reactive intermediates">Reactive intermediates</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:Articles_needing_additional_references_from_May_2010" title="Category:Articles needing additional references from May 2010">Articles needing additional references from May 2010</a></li><li><a href="/wiki/Category:All_articles_needing_additional_references" title="Category:All articles needing additional references">All articles needing additional references</a></li><li><a href="/wiki/Category:Articles_without_InChI_source" title="Category:Articles without InChI source">Articles without InChI source</a></li><li><a href="/wiki/Category:Articles_without_UNII_source" title="Category:Articles without UNII source">Articles without UNII source</a></li><li><a href="/wiki/Category:Articles_containing_unverified_chemical_infoboxes" title="Category:Articles containing unverified chemical infoboxes">Articles containing unverified chemical infoboxes</a></li><li><a href="/wiki/Category:Chembox_image_size_set" title="Category:Chembox image size set">Chembox image size set</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 10 January 2025, at 15:02<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=Hydroxyl_radical&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" lang="en" 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-header-container vector-sticky-header-container"> <div id="vector-sticky-header" class="vector-sticky-header"> <div class="vector-sticky-header-start"> <div class="vector-sticky-header-icon-start vector-button-flush-left vector-button-flush-right" aria-hidden="true"> <button class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-sticky-header-search-toggle" tabindex="-1" data-event-name="ui.vector-sticky-search-form.icon"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </button> </div> <div role="search" class="vector-search-box-vue vector-search-box-show-thumbnail vector-search-box"> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail"> <form action="/w/index.php" id="vector-sticky-search-form" class="cdx-search-input cdx-search-input--has-end-button"> <div 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"> <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> <div class="vector-sticky-header-context-bar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-sticky-header-toc" class="vector-dropdown mw-portlet mw-portlet-sticky-header-toc vector-sticky-header-toc vector-button-flush-left" > <input type="checkbox" id="vector-sticky-header-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-sticky-header-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-sticky-header-toc-label" for="vector-sticky-header-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-sticky-header-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div class="vector-sticky-header-context-bar-primary" aria-hidden="true" ><span class="mw-page-title-main">Hydroxyl radical</span></div> </div> </div> <div class="vector-sticky-header-end" aria-hidden="true"> <div class="vector-sticky-header-icons"> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-talk-sticky-header" tabindex="-1" data-event-name="talk-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbles mw-ui-icon-wikimedia-speechBubbles"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-subject-sticky-header" tabindex="-1" data-event-name="subject-sticky-header"><span class="vector-icon mw-ui-icon-article mw-ui-icon-wikimedia-article"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-history-sticky-header" tabindex="-1" data-event-name="history-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-history mw-ui-icon-wikimedia-wikimedia-history"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only mw-watchlink" id="ca-watchstar-sticky-header" tabindex="-1" data-event-name="watch-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-star mw-ui-icon-wikimedia-wikimedia-star"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-edit-sticky-header" tabindex="-1" data-event-name="wikitext-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-wikiText mw-ui-icon-wikimedia-wikimedia-wikiText"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-ve-edit-sticky-header" tabindex="-1" data-event-name="ve-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-edit mw-ui-icon-wikimedia-wikimedia-edit"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-viewsource-sticky-header" tabindex="-1" data-event-name="ve-edit-protected-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-editLock mw-ui-icon-wikimedia-wikimedia-editLock"></span> <span></span> </a> </div> <div class="vector-sticky-header-buttons"> <button class="cdx-button cdx-button--weight-quiet mw-interlanguage-selector" id="p-lang-btn-sticky-header" tabindex="-1" data-event-name="ui.dropdown-p-lang-btn-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-language mw-ui-icon-wikimedia-wikimedia-language"></span> <span>22 languages</span> </button> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive" id="ca-addsection-sticky-header" tabindex="-1" data-event-name="addsection-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbleAdd-progressive mw-ui-icon-wikimedia-speechBubbleAdd-progressive"></span> <span>Add topic</span> </a> </div> <div class="vector-sticky-header-icon-end"> <div class="vector-user-links"> </div> </div> </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-77bb847b5-xmw84","wgBackendResponseTime":127,"wgPageParseReport":{"limitreport":{"cputime":"0.982","walltime":"1.264","ppvisitednodes":{"value":8341,"limit":1000000},"postexpandincludesize":{"value":192569,"limit":2097152},"templateargumentsize":{"value":24553,"limit":2097152},"expansiondepth":{"value":25,"limit":100},"expensivefunctioncount":{"value":6,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":117937,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 1119.442 1 -total"," 46.53% 520.836 1 Template:Chembox"," 25.62% 286.826 1 Template:Chembox_Identifiers"," 23.24% 260.182 1 Template:Reflist"," 14.24% 159.372 5 Template:Chembox_headerbar"," 13.95% 156.155 15 Template:Trim"," 12.23% 136.951 1 Template:Molecules_detected_in_outer_space"," 12.15% 136.056 2 Template:Navbox"," 10.41% 116.552 20 Template:Cite_journal"," 10.03% 112.319 13 Template:Main_other"]},"scribunto":{"limitreport-timeusage":{"value":"0.524","limit":"10.000"},"limitreport-memusage":{"value":10934751,"limit":52428800},"limitreport-logs":"table#1 {\n [\"size\"] = \"tiny\",\n}\ntable#1 {\n [\"size\"] = \"tiny\",\n}\ntable#1 {\n [\"size\"] = \"tiny\",\n}\n"},"cachereport":{"origin":"mw-web.codfw.main-84749c7844-9mlgh","timestamp":"20250210045421","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Hydroxyl radical","url":"https:\/\/en.wikipedia.org\/wiki\/Hydroxyl_radical","sameAs":"http:\/\/www.wikidata.org\/entity\/Q427071","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q427071","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":"2004-06-20T06:28:03Z","dateModified":"2025-01-10T15:02:30Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/d\/db\/Hydroxyl_radical.svg","headline":"radical composed by one atom of oxygen and one atom of hydrogen"}</script> </body> </html>