{"id":3633,"date":"2011-12-15T12:00:54","date_gmt":"2011-12-15T12:00:54","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=3633"},"modified":"2026-01-16T13:33:40","modified_gmt":"2026-01-16T19:33:40","slug":"exploring-resonance-pi-donation","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/","title":{"rendered":"Pi-Donation and Pi-Donors"},"content":{"rendered":"<p><strong>Resonance In Organic Chemistry: Pi Donation and Pi Donors<\/strong><\/p>\n<ul>\n<li>In this article we discuss\u00a0<strong>pi-donation<\/strong>, which is just another way of saying that\u00a0<strong>atoms with a lone pair\u00a0<\/strong>that are<strong> directly attached to a pi bond,<\/strong> will have an important resonance structure where they <strong>form a new pi bond<\/strong> with the adjacent carbon.<\/li>\n<li>This has the impact of making the far end of the pi bond\u00a0<strong>more electron-rich<\/strong>.<\/li>\n<li>Pi bonds that have a nitrogen or oxygen directly attached are particularly electron-rich species.<\/li>\n<li>This doesn&#8217;t get discussed too much in first-semester organic chemistry but it becomes\u00a0<strong>very<\/strong> important in Org 2. <em>[<span style=\"color: #993366;\">Such as in <a style=\"color: #993366;\" href=\"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/\">electrophilic aromatic substitution<\/a>, for instance<\/span>]<\/em><\/li>\n<\/ul>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-38639\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\" alt=\"summary-pi donation in resonance to give more electron rich carbons oxygen nitrogen chlorine fluorine all capable of pi donation\" width=\"640\" height=\"585\" \/><\/a><\/p>\n<p><strong>Table of Contents<\/strong><\/p>\n<ol>\n<li><a href=\"#one\">Pi Donation: When An Atom With A Lone Pair Donates Its Electron Pair Into An Adjacent Pi-Bond, Making It More Electron Rich<\/a><\/li>\n<li><a href=\"#two\">Evidence For Pi Donation<\/a><\/li>\n<li><a href=\"#three\">How Pi Donation Influences Reactivity<\/a><\/li>\n<li><a href=\"#four\">The Presence Of A Pi Donor Will Result In Significant Negative Charge On The Far Carbon Of The Pi Bond<\/a><\/li>\n<li><a href=\"#notes\">Notes<\/a><\/li>\n<li><a href=\"#quizzes\">Quiz Yourself!<\/a><\/li>\n<\/ol>\n<hr \/>\n<h2><a id=\"one\"><\/a>1. Pi Donation: When An Atom With A Lone Pair Donates Its Electron Pair Into An Adjacent Pi-Bond, Making It More Electron Rich<\/h2>\n<p>The topic of today&#8217;s post is &#8220;\u03c0 donation&#8221;, which is just a way of describing what can occur in certain resonance forms where an atom with a <strong>lone pair<\/strong> can form a <strong>\u03c0 bond<\/strong> with an adjacent <strong>atom<\/strong> of appropriate hybridization.<\/p>\n<p>Let&#8217;s look at the resonance forms of an <strong>enol<\/strong> (shown) and use what has already been discussed to evaluate their relative importance. Note that in order to draw resonance form D we have to do <strong>two<\/strong>\u00a0arrow moves to avoid breaking the octet rule (<span style=\"color: #993366;\"><em>See post: <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/11\/30\/introduction-to-resonance-2-curved-arrows\/\">Using Curved Arrows To Interconvert Resonance Forms<\/a><\/em><\/span>)<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-43213\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/11\/1-what-is-pi-donation-it-is-when-lone-pair-on-atom-attached-to-pi-bond-can-form-new-pi-bond-increasing-electron-density-of-pi-bond-eg-enol.gif\" alt=\"what is pi donation it is when lone pair on atom attached to pi bond can form new pi bond increasing electron density of pi bond eg enol\" width=\"640\" height=\"444\" \/><\/a><\/p>\n<ul>\n<li>Resonance form A has the <strong>fewest<\/strong> charges.<\/li>\n<li>Resonance form B has <strong>two<\/strong> charges, but all atoms have <strong>full octets.<\/strong><\/li>\n<\/ul>\n<p>There are also two minor resonance forms which are quite insignificant:<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-43214\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2026\/01\/2-minor-resonance-forms-of-enol-are-much-less-significant-because-they-lack-full-octet-on-carbon.gif\" alt=\"minor resonance forms of enol are much less significant because they lack full octet on carbon\" width=\"640\" height=\"236\" \/><\/a><\/p>\n<ul>\n<li>Resonance forms C and D each have two charges, but have <strong>empty<\/strong> octets on the carbons.<\/li>\n<\/ul>\n<p>In evaluating these resonance forms, <strong>A will be most important<\/strong> due to the rule of fewest charges. B<strong>\u00a0will be the second-most important<\/strong> since we always give atoms full octets if possible. And C and D will be the <strong>least important<\/strong> because each of them have atoms with less than full octets.<\/p>\n<h2><a id=\"two\"><\/a>2. Evidence For Pi Donation<\/h2>\n<p>While that&#8217;s nice, you should go on more than just some dude on the Internet&#8217;s appraisal of what resonance forms are most important. What about experimental evidence?<\/p>\n<p>Here&#8217;s three pieces of experimental evidence to support the proposal that resonance form D is more important than B and C.<\/p>\n<ul>\n<li><strong>reactivity<\/strong> profile (shown below) &#8211; enols tend to react with electropositive groups such as protons (H+ ) at the site where they bear a partial negative charge (opposite charges attract, remember). This supports a resonance form such as D being more important than, say B. [<span style=\"color: #993366;\"><i>See article: <a href=\"https:\/\/www.masterorganicchemistry.com\/2010\/06\/02\/the-acid-catalyzed-aldol-reaction\/\">Reactions of Enols &#8211; Halogenation, Protonation and the Aldol<\/a><\/i><\/span>]<\/li>\n<li><strong>proton NMR<\/strong> spectroscopy is a good guide to<strong> electron density<\/strong>, and protons on the enolate carbon are shifted downfield relative to alkenes (this indicates the carbon is more electron rich, which supports the importance of resonance form D).<\/li>\n<li>electrostatic potential maps (although I can&#8217;t find a good one for the enol shown, <a href=\"http:\/\/www.chem.ucalgary.ca\/courses\/350\/Carey5th\/Ch18\/ch18-1.html\" target=\"_blank\" rel=\"noopener noreferrer\">here&#8217;s one for a related species<\/a>. Note how there is less positive charge on one of the carbons).<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-43215\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2026\/01\/3-experiments-tell-us-protonation-of-enol-ether-with-deuterium-results-in-protonation-of-alpha-carbon-contribution-from-second-best-resonance-form.gif\" alt=\"experiments tell us protonation of enol ether with deuterium results in protonation of alpha carbon contribution from second best resonance form\" width=\"640\" height=\"411\" \/><\/a><\/p>\n<p>Furthermore, molecules like the ones below would be expected to show similar behavior &#8211; and they do.<\/p>\n<h2><a id=\"three\"><\/a>3. How Pi Donation Influences Reactivity<\/h2>\n<p>Enamines (the one on the left) are well known to react with positive species at the end carbon (C1) (<span style=\"color: #993366;\"><em>See article: <a href=\"https:\/\/www.masterorganicchemistry.com\/2010\/05\/24\/imines-and-enamines\/\">All About Enamines<\/a><\/em><\/span>).\u00a0 Vinyl chlorides, although less reactive, will also react with positive species at the end carbon (C-1)<\/p>\n<p>Take home message: <strong>alkenes<\/strong> attached to an atom with a <strong>lone pair<\/strong> such as O, N, Cl, S, etc. (<span style=\"color: #993366;\"><em>often called \u00a0&#8220;heteroatoms&#8221;<\/em><\/span>) have an important <strong>resonance form<\/strong> with a <strong>negative<\/strong> charge adjacent to the carbon-atom bond.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-43216\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2026\/01\/4-pi-donation-explains-why-enamines-protonate-on-alpha-carbon-also-vinyl-chlorides.gif\" alt=\"pi donation explains why enamines protonate on alpha carbon also vinyl chlorides\" width=\"640\" height=\"336\" \/><\/a><\/p>\n<p>So what does it matter?<\/p>\n<p>Although it deserves a post of its own, <strong>the concept of \u03c0 donation is probably the most important application of resonance you learn in Org 2<\/strong>. It influences <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/01\/19\/what-to-expect-in-organic-chemistry-2\/\" target=\"_blank\" rel=\"noopener noreferrer\">everything covered in that course<\/a>: reactions of aromatic rings, reactions of dienes, and especially reactions of carbonyl compounds.<\/p>\n<h2><a id=\"four\"><\/a>4. The Presence Of A Pi Donor Will Result In Significant Negative Charge On The Far Carbon Of The Pi Bond<\/h2>\n<p>Here&#8217;s the key point of this post.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-43217\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2026\/01\/5-pi-donating-substituents-attached-to-carbon-carbon-pi-bond-there-will-be-important-resonance-form-with-neg-charge-on-carbon-resonance-hybrid-has-partial-negative-charge.gif\" alt=\"pi donating substituents attached to carbon carbon pi bond there will be important resonance form with neg charge on carbon resonance hybrid has partial negative charge\" width=\"640\" height=\"337\" \/><\/a><\/p>\n<p>This will have tremendous consequences for chemical reactivity, which will be the subject of a later post. For the moment I&#8217;ll just leave with a final application of \u03c0\u00a0donation. And a \u00a0question.<\/p>\n<p>For which of these molecules do you think \u03c0\u00a0donation is going to be the <strong>most<\/strong> important?<\/p>\n<p>That is, what types of atoms would be <strong>more likely<\/strong> to \u00a0to give away their <strong>lone pairs<\/strong> to form <strong>\u03c0\u00a0bonds<\/strong>?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-43218\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2026\/01\/6-application-of-pi-donation-is-partial-double-bond-character-of-amides-and-esters.gif\" alt=\"application of pi donation is partial double bond character of amides and esters\" width=\"640\" height=\"531\" \/><\/a><\/p>\n<p><strong>Hint:<\/strong> it has something to do with electronegativity. [<a href=\"#noteone\"><strong>Note 1<\/strong><\/a>]<\/p>\n<p>In the next (and for now hopefully last ) post on resonance concepts, we&#8217;ll talk about the opposite of \u03c0 donation: \u03c0 accepting.<\/p>\n<p><strong>Next Post: <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/19\/exploring-resonance-pi-acceptors\/\">Applying Resonance (2): Pi Acceptors<\/a><\/strong><\/p>\n<hr \/>\n<h2><a id=\"notes\"><\/a>Notes<\/h2>\n<div class=\"related-articles\"><p><strong>Related Articles<\/strong><\/p><ul><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/19\/exploring-resonance-pi-acceptors\/\" class=\"\"><span>Exploring Resonance: Pi-acceptors<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/11\/30\/introduction-to-resonance-2-curved-arrows\/\" class=\"\"><span>How To Use Curved Arrows To Interchange Resonance Forms<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/08\/evaluating-resonance-forms-1-the-rule-of-least-charges\/\" class=\"\"><span>Evaluating Resonance Forms (1) \u2013 The Rule of Least Charges<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/13\/evaluating-resonance-forms-3-where-to-put-the-negative-charge\/\" class=\"\"><span>Evaluating Resonance Structures With Negative Charges<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/22\/in-summary-resonance\/\" class=\"\"><span>In Summary: Evaluating Resonance Structures<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2012\/01\/10\/common-mistakes-how-not-to-draw-resonance-curved-arrows\/\" class=\"\"><span>Drawing Resonance Structures: 3 Common Mistakes To Avoid<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2017\/09\/26\/activating-and-deactivating-groups-in-electrophilic-aromatic-substitution\/\" class=\"\"><span>Activating and Deactivating Groups In Electrophilic Aromatic Substitution<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2010\/06\/02\/the-acid-catalyzed-aldol-reaction\/\" class=\"\"><span>Reactions of Enols \u2013 Acid-Catalyzed Aldol, Halogenation, and Mannich Reactions<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2010\/05\/24\/imines-and-enamines\/\" class=\"\"><span>All About Enamines<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/organic-chemistry-practice-problems\/resonance-structures-practice\/\" class=\"\"><span>Resonance Structures Practice (MOC Membership)<\/span><\/a><\/li><\/ul><\/div>\n<p><span style=\"color: #000000;\"><strong><span class=\"Apple-style-span\"><a id=\"noteone\"><\/a>Note 1 <\/span><\/strong><span class=\"Apple-style-span\"><span style=\"color: #000000;\">Across a row, \u03c0 donation is <em>inversely<\/em>\u00a0related to electronegativity. However caution is advised when using electronegativity to compare \u03c0 donation when going down the periodic table &#8211; other effects, such as orbital overlap, also come into play.\u00a0<\/span><\/span><\/span><\/p>\n<hr \/>\n<h2><a id=\"quizzes\"><\/a>Quiz Yourself!<\/h2>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0033-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0020-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0021-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0027-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3675-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n\n<p class=\"p1\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-26714\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3677-Front-Image-Only.png\" alt=\"\" width=\"640\" height=\"616\" \/><\/p>\n<p><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a\u00a0 MOC member<\/strong><\/a> to see the clickable quiz with answers on the back. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Resonance In Organic Chemistry: Pi Donation and Pi Donors In this article we discuss\u00a0pi-donation, which is just another way of saying that\u00a0atoms with a lone <\/p>\n","protected":false},"author":1,"featured_media":38639,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1406],"tags":[298,334,395,304,204,305,267],"post_folder":[],"class_list":["post-3633","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bonding-structure-resonance","tag-curved-arrows","tag-electron-density","tag-electron-pushing","tag-enamines","tag-enols","tag-pi-donation","tag-resonance"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic<\/title>\n<meta name=\"description\" content=\"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C &amp; pushing electron density to the terminal C\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic\" \/>\n<meta property=\"og:description\" content=\"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C &amp; pushing electron density to the terminal C\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/\" \/>\n<meta property=\"og:site_name\" content=\"Master Organic Chemistry\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/\" \/>\n<meta property=\"article:published_time\" content=\"2011-12-15T12:00:54+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-01-16T19:33:40+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\" \/>\n\t<meta property=\"og:image:width\" content=\"904\" \/>\n\t<meta property=\"og:image:height\" content=\"826\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/gif\" \/>\n<meta name=\"author\" content=\"James Ashenhurst\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"James Ashenhurst\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"6 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/\"},\"author\":{\"name\":\"James Ashenhurst\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\"},\"headline\":\"Pi-Donation and Pi-Donors\",\"datePublished\":\"2011-12-15T12:00:54+00:00\",\"dateModified\":\"2026-01-16T19:33:40+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/\"},\"wordCount\":1041,\"commentCount\":13,\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2024\\\/12\\\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\",\"keywords\":[\"curved arrows\",\"electron density\",\"electron pushing\",\"enamines\",\"enols\",\"pi donation\",\"resonance\"],\"articleSection\":[\"Bonding, Structure, and Resonance\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/\",\"name\":\"Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2024\\\/12\\\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\",\"datePublished\":\"2011-12-15T12:00:54+00:00\",\"dateModified\":\"2026-01-16T19:33:40+00:00\",\"description\":\"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C & pushing electron density to the terminal C\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2024\\\/12\\\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2024\\\/12\\\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif\",\"width\":904,\"height\":826,\"caption\":\"summary-pi donation in resonance to give more electron rich carbons oxygen nitrogen chlorine fluorine all capable of pi donation\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2011\\\/12\\\/15\\\/exploring-resonance-pi-donation\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Pi-Donation and Pi-Donors\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"name\":\"Master Organic Chemistry\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\",\"name\":\"Master Organic Chemistry\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/04\\\/cutmypic.png\",\"width\":225,\"height\":225,\"caption\":\"Master Organic Chemistry\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/Master-Organic-Chemistry-242610599108055\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\",\"name\":\"James Ashenhurst\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g\",\"caption\":\"James Ashenhurst\"},\"description\":\"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.\",\"sameAs\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/about\\\/\"],\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/author\\\/james\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic","description":"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C & pushing electron density to the terminal C","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/","og_locale":"en_US","og_type":"article","og_title":"Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic","og_description":"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C & pushing electron density to the terminal C","og_url":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/","og_site_name":"Master Organic Chemistry","article_publisher":"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/","article_published_time":"2011-12-15T12:00:54+00:00","article_modified_time":"2026-01-16T19:33:40+00:00","og_image":[{"width":904,"height":826,"url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif","type":"image\/gif"}],"author":"James Ashenhurst","twitter_card":"summary_large_image","twitter_misc":{"Written by":"James Ashenhurst","Est. reading time":"6 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#article","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/"},"author":{"name":"James Ashenhurst","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c"},"headline":"Pi-Donation and Pi-Donors","datePublished":"2011-12-15T12:00:54+00:00","dateModified":"2026-01-16T19:33:40+00:00","mainEntityOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/"},"wordCount":1041,"commentCount":13,"publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif","keywords":["curved arrows","electron density","electron pushing","enamines","enols","pi donation","resonance"],"articleSection":["Bonding, Structure, and Resonance"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/","url":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/","name":"Pi Donors And Resonance - Pi Donors Make Carbons More Nucleophilic","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#primaryimage"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif","datePublished":"2011-12-15T12:00:54+00:00","dateModified":"2026-01-16T19:33:40+00:00","description":"Lone-pair bearing atoms such as oxygen and nitrogen can be pi donors - forming a pi bond with an adjacent C & pushing electron density to the terminal C","breadcrumb":{"@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#primaryimage","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2024\/12\/0-summary-pi-donation-in-resonance-to-give-more-electron-rich-carbons-oxygen-nitrogen-chlorine-fluorine-all-capable-of-pi-donation.gif","width":904,"height":826,"caption":"summary-pi donation in resonance to give more electron rich carbons oxygen nitrogen chlorine fluorine all capable of pi donation"},{"@type":"BreadcrumbList","@id":"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.masterorganicchemistry.com\/"},{"@type":"ListItem","position":2,"name":"Pi-Donation and Pi-Donors"}]},{"@type":"WebSite","@id":"https:\/\/www.masterorganicchemistry.com\/#website","url":"https:\/\/www.masterorganicchemistry.com\/","name":"Master Organic Chemistry","description":"","publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.masterorganicchemistry.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.masterorganicchemistry.com\/#organization","name":"Master Organic Chemistry","url":"https:\/\/www.masterorganicchemistry.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/04\/cutmypic.png","width":225,"height":225,"caption":"Master Organic Chemistry"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/"]},{"@type":"Person","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c","name":"James Ashenhurst","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/f9e9df435875e5e6b0bdff6b8522a7279d5717644b3efa7299da22c837bf9fcf?s=96&d=retro&r=g","caption":"James Ashenhurst"},"description":"Ph.D. 2006, McGill University (James L. Gleason). Postdoctoral Associate, 2008-2010, Massachusetts Institute of Technology (M. Movassaghi). Founder, Master Organic Chemistry, 2010-present.","sameAs":["https:\/\/www.masterorganicchemistry.com\/about\/"],"url":"https:\/\/www.masterorganicchemistry.com\/author\/james\/"}]}},"_links":{"self":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/3633","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/comments?post=3633"}],"version-history":[{"count":0,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/3633\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media\/38639"}],"wp:attachment":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media?parent=3633"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/categories?post=3633"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/tags?post=3633"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/post_folder?post=3633"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}