{"id":802,"date":"2018-11-28T15:33:08","date_gmt":"2018-11-28T15:33:08","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/?post_type=chapter&#038;p=802"},"modified":"2019-01-07T21:39:01","modified_gmt":"2019-01-07T21:39:01","slug":"18-2-homolysis","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/chapter\/18-2-homolysis\/","title":{"raw":"18.2. Homolysis","rendered":"18.2. Homolysis"},"content":{"raw":"<div class=\"mw-indicators mw-body-content\"><span style=\"font-size: 1rem;text-align: initial\">In <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Chemistry\" href=\"\/wiki\/Chemistry\">chemistry<\/a><span style=\"font-size: 1rem;text-align: initial\">, <\/span><b style=\"font-size: 1rem;text-align: initial\">homolysis<\/b><span style=\"font-size: 1rem;text-align: initial\"> (from Greek \u1f45\u03bc\u03bf\u03b9\u03bf\u03c2, homoios, \"equal,\" and \u03bb\u03cd\u03c3\u03b9\u03c2, lusis, \"loosening\") or <\/span><b style=\"font-size: 1rem;text-align: initial\">homolytic fission<\/b><span style=\"font-size: 1rem;text-align: initial\"> is <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Chemical bond\" href=\"\/wiki\/Chemical_bond\">chemical bond<\/a><span style=\"font-size: 1rem;text-align: initial\"> dissociation of a <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Molecule\" href=\"\/wiki\/Molecule\">molecule<\/a><span style=\"font-size: 1rem;text-align: initial\"> by a process where each of the fragments retains one of the originally bonded electrons. During homolytic fission of a neutral molecule with an even number of electrons, two <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Free-radical halogenation\" href=\"\/wiki\/Free-radical_halogenation\">free radicals<\/a><span style=\"font-size: 1rem;text-align: initial\"> will be generated.<\/span><sup id=\"cite_ref-1\" class=\"reference\" style=\"text-align: initial\"><a href=\"#cite_note-1\">[1]<\/a><\/sup><span style=\"font-size: 1rem;text-align: initial\"> That is, the two <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Electron\" href=\"\/wiki\/Electron\">electrons<\/a><span style=\"font-size: 1rem;text-align: initial\"> involved in the original bond are distributed between the two fragment species. The energy involved in this process is called <\/span><a class=\"mw-redirect\" style=\"font-size: 1rem;text-align: initial\" title=\"Bond dissociation energy\" href=\"\/wiki\/Bond_dissociation_energy\">bond dissociation energy<\/a><span style=\"font-size: 1rem;text-align: initial\">. Bond cleavage is also possible by a process called <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Heterolysis (chemistry)\" href=\"\/wiki\/Heterolysis_(chemistry)\">heterolysis<\/a><span style=\"font-size: 1rem;text-align: initial\">.<\/span><\/div>\r\n<div><img class=\"aligncenter\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/5\/5b\/Homolysis_%28Chemistry%29.png\/350px-Homolysis_%28Chemistry%29.png\" alt=\"Homolysis (Chemistry).png\" \/><\/div>\r\n<div id=\"bodyContent\" class=\"mw-body-content\">\r\n<div id=\"mw-content-text\" class=\"mw-content-ltr\" dir=\"ltr\" xml:lang=\"en\">\r\n<div class=\"mw-parser-output\">\r\n\r\nBecause the relatively high energy required to break bonds in this manner, homolysis only occurs under certain circumstances:\r\n<ul>\r\n \t<li><a title=\"Ultraviolet\" href=\"\/wiki\/Ultraviolet\">Ultraviolet<\/a> radiation (e.g. sunlight causing sunburns)<\/li>\r\n \t<li>Heat\r\n<ul>\r\n \t<li>Certain intramolecular bonds, such as the O\u2013O bond of a <a title=\"Peroxide\" href=\"\/wiki\/Peroxide\">peroxide<\/a>, are weak enough to spontaneously homolytically dissociate with a small amount of heat.<\/li>\r\n \t<li>High temperatures in the absence of oxygen (<a title=\"Pyrolysis\" href=\"\/wiki\/Pyrolysis\">pyrolysis<\/a>) can induce homolytic elimination of <a title=\"Compounds of carbon\" href=\"\/wiki\/Compounds_of_carbon\">carbon compounds<\/a>.<sup id=\"cite_ref-2\" class=\"reference\"><a href=\"#cite_note-2\">[2]<\/a><\/sup><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2><span id=\"References\" class=\"mw-headline\" style=\"background-color: #ffff00\">References<\/span><\/h2>\r\n<div class=\"reflist\">\r\n<div class=\"mw-references-wrap\">\r\n<ol class=\"references\">\r\n \t<li id=\"cite_note-1\"><span class=\"mw-cite-backlink\"><b><a href=\"#cite_ref-1\">^<\/a><\/b><\/span> <span class=\"reference-text\"><a title=\"International Union of Pure and Applied Chemistry\" href=\"\/wiki\/International_Union_of_Pure_and_Applied_Chemistry\">IUPAC<\/a>, <i><a class=\"mw-redirect\" title=\"Compendium of Chemical Terminology\" href=\"\/wiki\/Compendium_of_Chemical_Terminology\">Compendium of Chemical Terminology<\/a><\/i>, 2nd ed. (the \"Gold Book\") (1997). Online corrected version: \u00a0(2006\u2013) \"<a class=\"external text\" href=\"http:\/\/goldbook.iupac.org\/H02851.html\" rel=\"nofollow\">homolysis (homolytic)<\/a>\". <\/span><\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div class=\"navbox\" role=\"navigation\"><\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"<div class=\"mw-indicators mw-body-content\"><span style=\"font-size: 1rem;text-align: initial\">In <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Chemistry\" href=\"\/wiki\/Chemistry\">chemistry<\/a><span style=\"font-size: 1rem;text-align: initial\">, <\/span><b style=\"font-size: 1rem;text-align: initial\">homolysis<\/b><span style=\"font-size: 1rem;text-align: initial\"> (from Greek \u1f45\u03bc\u03bf\u03b9\u03bf\u03c2, homoios, &#8220;equal,&#8221; and \u03bb\u03cd\u03c3\u03b9\u03c2, lusis, &#8220;loosening&#8221;) or <\/span><b style=\"font-size: 1rem;text-align: initial\">homolytic fission<\/b><span style=\"font-size: 1rem;text-align: initial\"> is <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Chemical bond\" href=\"\/wiki\/Chemical_bond\">chemical bond<\/a><span style=\"font-size: 1rem;text-align: initial\"> dissociation of a <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Molecule\" href=\"\/wiki\/Molecule\">molecule<\/a><span style=\"font-size: 1rem;text-align: initial\"> by a process where each of the fragments retains one of the originally bonded electrons. During homolytic fission of a neutral molecule with an even number of electrons, two <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Free-radical halogenation\" href=\"\/wiki\/Free-radical_halogenation\">free radicals<\/a><span style=\"font-size: 1rem;text-align: initial\"> will be generated.<\/span><sup id=\"cite_ref-1\" class=\"reference\" style=\"text-align: initial\"><a href=\"#cite_note-1\">[1]<\/a><\/sup><span style=\"font-size: 1rem;text-align: initial\"> That is, the two <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Electron\" href=\"\/wiki\/Electron\">electrons<\/a><span style=\"font-size: 1rem;text-align: initial\"> involved in the original bond are distributed between the two fragment species. The energy involved in this process is called <\/span><a class=\"mw-redirect\" style=\"font-size: 1rem;text-align: initial\" title=\"Bond dissociation energy\" href=\"\/wiki\/Bond_dissociation_energy\">bond dissociation energy<\/a><span style=\"font-size: 1rem;text-align: initial\">. Bond cleavage is also possible by a process called <\/span><a style=\"font-size: 1rem;text-align: initial\" title=\"Heterolysis (chemistry)\" href=\"\/wiki\/Heterolysis_(chemistry)\">heterolysis<\/a><span style=\"font-size: 1rem;text-align: initial\">.<\/span><\/div>\n<div><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/5\/5b\/Homolysis_%28Chemistry%29.png\/350px-Homolysis_%28Chemistry%29.png\" alt=\"Homolysis (Chemistry).png\" \/><\/div>\n<div id=\"bodyContent\" class=\"mw-body-content\">\n<div id=\"mw-content-text\" class=\"mw-content-ltr\" dir=\"ltr\" xml:lang=\"en\">\n<div class=\"mw-parser-output\">\n<p>Because the relatively high energy required to break bonds in this manner, homolysis only occurs under certain circumstances:<\/p>\n<ul>\n<li><a title=\"Ultraviolet\" href=\"\/wiki\/Ultraviolet\">Ultraviolet<\/a> radiation (e.g. sunlight causing sunburns)<\/li>\n<li>Heat\n<ul>\n<li>Certain intramolecular bonds, such as the O\u2013O bond of a <a title=\"Peroxide\" href=\"\/wiki\/Peroxide\">peroxide<\/a>, are weak enough to spontaneously homolytically dissociate with a small amount of heat.<\/li>\n<li>High temperatures in the absence of oxygen (<a title=\"Pyrolysis\" href=\"\/wiki\/Pyrolysis\">pyrolysis<\/a>) can induce homolytic elimination of <a title=\"Compounds of carbon\" href=\"\/wiki\/Compounds_of_carbon\">carbon compounds<\/a>.<sup id=\"cite_ref-2\" class=\"reference\"><a href=\"#cite_note-2\">[2]<\/a><\/sup><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><span id=\"References\" class=\"mw-headline\" style=\"background-color: #ffff00\">References<\/span><\/h2>\n<div class=\"reflist\">\n<div class=\"mw-references-wrap\">\n<ol class=\"references\">\n<li id=\"cite_note-1\"><span class=\"mw-cite-backlink\"><b><a href=\"#cite_ref-1\">^<\/a><\/b><\/span> <span class=\"reference-text\"><a title=\"International Union of Pure and Applied Chemistry\" href=\"\/wiki\/International_Union_of_Pure_and_Applied_Chemistry\">IUPAC<\/a>, <i><a class=\"mw-redirect\" title=\"Compendium of Chemical Terminology\" href=\"\/wiki\/Compendium_of_Chemical_Terminology\">Compendium of Chemical Terminology<\/a><\/i>, 2nd ed. (the &#8220;Gold Book&#8221;) (1997). Online corrected version: \u00a0(2006\u2013) &#8220;<a class=\"external text\" href=\"http:\/\/goldbook.iupac.org\/H02851.html\" rel=\"nofollow\">homolysis (homolytic)<\/a>&#8220;. <\/span><\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div class=\"navbox\" role=\"navigation\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-802\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Homolysis (chemistry). <strong>Authored by<\/strong>: Wikipedia. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Homolysis_(chemistry)\">https:\/\/en.wikipedia.org\/wiki\/Homolysis_(chemistry)<\/a>. <strong>Project<\/strong>: Wikipedia. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":53384,"menu_order":2,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Homolysis (chemistry)\",\"author\":\"Wikipedia\",\"organization\":\"Wikipedia\",\"url\":\"https:\/\/en.wikipedia.org\/wiki\/Homolysis_(chemistry)\",\"project\":\"Wikipedia\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-802","chapter","type-chapter","status-publish","hentry"],"part":784,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/802","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/users\/53384"}],"version-history":[{"count":7,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/802\/revisions"}],"predecessor-version":[{"id":2805,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/802\/revisions\/2805"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/parts\/784"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapters\/802\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/media?parent=802"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/pressbooks\/v2\/chapter-type?post=802"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/contributor?post=802"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-potsdam-organicchemistry2\/wp-json\/wp\/v2\/license?post=802"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}