{"id":11291,"date":"2018-02-02T07:00:30","date_gmt":"2018-02-02T12:00:30","guid":{"rendered":"https:\/\/www.masterorganicchemistry.com\/?p=11291"},"modified":"2026-04-22T12:35:30","modified_gmt":"2026-04-22T17:35:30","slug":"understanding-ortho-para-meta-directors","status":"publish","type":"post","link":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/","title":{"rendered":"Understanding Ortho, Para, and Meta Directors"},"content":{"rendered":"<p><strong><em>Ortho-, Para<\/em>&#8211; and <em>Meta<\/em>&#8211; Directors<\/strong><\/p>\n<ul>\n<li>In Electrophilic Aromatic Substitution (EAS), some substituents on benzene will direct the electrophile\u00a0<strong>E<\/strong> to the\u00a0<em>ortho<\/em>&#8211; (1,2)and <em>para<\/em>&#8211; (1,4) positions. These are called, &#8220;<em>ortho, para- <\/em>directors&#8221;.<\/li>\n<li>Another class of substituents avoids directing the electrophile E to those positions, with the result that the\u00a0<em>meta- <\/em>product (1,3) is major. These are called, &#8220;<em>meta-\u00a0<\/em>directors&#8221;.<\/li>\n<li>The ultimate factor which determines whether a substituent is\u00a0<em>ortho-, para-<\/em> or\u00a0<em>meta-<\/em> directing is\u00a0<strong>how well it stabilizes an adjacent carbocation.\u00a0<\/strong><\/li>\n<li>Substituents that have a lone pair on the atom adjacent to the aromatic ring will be <em>ortho-, para-<\/em> directors since this can form a new pi-bond with an adjacent carbocation.<\/li>\n<li>Substituents that pull electron density away from adjacent carbocations (e.g. CF<sub>3<\/sub>, NO<sub>2<\/sub>)will avoid directing <strong>E<\/strong> to the\u00a0<em>ortho-\u00a0<\/em>or\u00a0<em>para-<\/em> position with the result that the <em>meta-<\/em> product forms instead.<\/li>\n<\/ul>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone wp-image-15875\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\" alt=\"summary of ortho meta and para directors explanation with resonance structures pi donors and pi acceptors\" width=\"630\" height=\"529\" \/><\/p>\n<p><strong>Table Of Contents<\/strong><\/p>\n<ol>\n<li class=\"p1\"><a href=\"#one\"><span class=\"s1\">Carbocations Are Stabilized By Adjacent Atoms With Lone Pairs<\/span><\/a><\/li>\n<li class=\"p1\"><a href=\"#two\"><span class=\"s1\">Case Study #1: An <i>ortho-,para-<\/i> Director (OCH<\/span><span class=\"s2\"><sub>3<\/sub><\/span><span class=\"s1\">)\u00a0<\/span><\/a><\/li>\n<li class=\"p1\"><a href=\"#three\"><span class=\"s1\"><span class=\"s1\">Yes, Oxygen Is Electronegative.\u00a0 But Donation Of Its Lone Pair More Than Makes Up For It!<\/span><\/span><\/a><\/li>\n<li class=\"p1\"><a href=\"#four\">The Reaction-Energy Diagram For An Ortho Para Director<\/a><\/li>\n<li class=\"p1\"><a href=\"#five\">Case Study #2: A <i>meta-\u00a0<\/i>director (CF<span class=\"s2\"><sub>3<\/sub><\/span><span class=\"s1\"><span class=\"s1\">).<\/span><\/span><\/a><\/li>\n<li class=\"p1\"><a href=\"#six\">What We Call &#8220;<i>meta<\/i>&#8211; Directors&#8221; Are More Like &#8220;<i>ortho<\/i>-, <i>para<\/i>&#8211; Avoiders&#8221;<\/a><\/li>\n<li class=\"p1\"><a href=\"#seven\">The Reaction Energy Diagram For A\u00a0<i>meta-\u00a0<\/i>Director<\/a><\/li>\n<li class=\"p1\"><a href=\"#eight\"><span class=\"s1\">So Why Are Halogens Ortho-, Para- Directors?<\/span><\/a><\/li>\n<li><a href=\"#notes\">Notes<\/a><\/li>\n<li><a href=\"#quiz\">Quiz Yourself!\u00a0<\/a><\/li>\n<li><a href=\"#references\">(Advanced) References and Further Reading<\/a><\/li>\n<\/ol>\n<hr \/>\n<h2><strong><a id=\"one\"><\/a>1. Carbocations Are Stabilized By Adjacent Atoms With Lone Pairs<\/strong><\/h2>\n<p>In the previous post we introduced <a href=\"https:\/\/www.masterorganicchemistry.com\/2018\/01\/29\/ortho-para-and-meta-directors-in-electrophilic-aromatic-substitution\/\"><em>ortho- ,para-<\/em> and <em>meta-<\/em> directors<\/a>\u00a0in electrophilic aromatic substitution.\u00a0 Previous to that we covered the <a href=\"https:\/\/www.masterorganicchemistry.com\/2017\/11\/09\/electrophilic-aromatic-substitution-the-mechanism\/\">mechanism of electrophilic aromatic substitution<\/a>, and showed that the mechanism proceeds through a carbocation intermediate.<\/p>\n<p>Today, we&#8217;re going to tie those two concepts together, and try to show that\u00a0whether a substituent is an\u00a0<em>ortho-, para-\u00a0<\/em>or\u00a0<em>meta-<\/em> director depends on\u00a0<strong>how the substituent affects the stability of the carbocation intermediate.\u00a0<\/strong><\/p>\n<p>And we&#8217;ll also see why an alternative name for\u00a0<em>meta-<\/em> director might be, &#8220;<em>ortho-, para-\u00a0<\/em>avoider&#8221;. : &#8211; )<\/p>\n<hr \/>\n<p>Let&#8217;s think back to which factors<em> increase<\/em> the stability of carbocations. <em>[See, &#8220;<a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/03\/11\/3-factors-that-stabilize-carbocations\/\" target=\"_blank\" rel=\"noopener noreferrer\">3 Factors that Stabilize Carbocations<\/a>&#8220;]<\/em><\/p>\n<p>Carbocations are electron-poor species with six electrons in their valence shell. So, any substituent which can <em>donate<\/em> electron density toward the carbocation will be stabilizing. This includes:<\/p>\n<ul>\n<li><strong>electron-releasing substituents<\/strong> that can act as &#8220;sigma-donors&#8221; (e.g. many alkyl groups, which donate electron density through inductive effects [<a href=\"#noteone\">Note 1<\/a>])<\/li>\n<li><strong>adjacent atoms with lone pairs<\/strong> that can act as &#8220;<a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/\">pi donors<\/a>&#8221; to the carbocation<\/li>\n<li><strong>adjacent C\u2013C pi bonds<\/strong> that can stabilize the carbocation through charge delocalization (&#8220;resonance stabilization&#8221;, in other words).<\/li>\n<\/ul>\n<p>And factors which destabilize carbocations?<\/p>\n<ul>\n<li>any substituent that <strong>removes electron density<\/strong> from a carbocation, such as strong electron-withdrawing groups.<\/li>\n<\/ul>\n<p>So here&#8217;s a quick quiz. Given everything written above, which of the two carbocations below will be more stable?<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15876\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/1-carbocations-are-stabilized-by-substituents-with-lone-pairs-through-pi-donation.gif\" alt=\"carbocations are stabilized by substituents with lone pairs through pi donation\" width=\"600\" height=\"134\" \/><\/p>\n<p>If you can answer this question well, you are most of the way towards understanding the difference between\u00a0<em>ortho-, para-\u00a0<\/em>and\u00a0<em>meta-<\/em> directors.<\/p>\n<p>Let&#8217;s examine two case studies. We&#8217;ll look at a generic electrophilic aromatic substitution reaction of benzene with an\u00a0<em>ortho-, para-\u00a0<\/em>director (methoxybenzene) and examine the intermediates that are obtained from attack at the\u00a0<em>ortho<\/em>,\u00a0<em>meta<\/em>, and\u00a0<em>para<\/em> positions. Then we&#8217;ll perform the same exercise with a\u00a0<em>meta<\/em>&#8211; director (trifluoromethylbenzene).<\/p>\n<p>In the process, we&#8217;ll hope to understand why methoxybenzene favors\u00a0<em>ortho-\u00a0<\/em>and\u00a0<em>para<\/em>&#8211; products while trifluoromethylbenzene favors\u00a0the\u00a0<em>meta-\u00a0<\/em>product.<\/p>\n<h2><strong><a id=\"two\"><\/a>2. Case Study #1: An <em>o<\/em><em>rtho-,para-<\/em> Director (OCH<sub>3<\/sub>)\u00a0<\/strong><\/h2>\n<p>Electrophilic aromatic substitution of methoxybenzene tends to give <em>ortho-\u00a0<\/em>and\u00a0<em>para-<\/em> products with very little\u00a0<em>meta-<\/em> .\u00a0Here&#8217;s what happens in nitration, for example:<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-15877\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/2-electrophilic-aromatic-substitution-of-methoxybenzene-gives-mostly-ortho-and-para-products.gif\" alt=\"electrophilic aromatic substitution of methoxybenzene gives mostly ortho and para products\" width=\"600\" height=\"306\" \/><\/p>\n<p>The\u00a0<em>para-<\/em> product dominates (60-70%), with\u00a0<em>ortho-\u00a0<\/em>close behind (30-40%) and only a trace of the\u00a0<em>meta<\/em>&#8211; .<\/p>\n<p><strong>Why?\u00a0<\/strong><\/p>\n<h2><a id=\"three\"><\/a>3. Yes, Oxygen Is Electronegative.\u00a0 But Donation Of Its Lone Pair More Than Makes Up For It!<\/h2>\n<p>Here&#8217;s the pathway leading to the <em>ortho-<\/em>\u00a0product. We break a C\u2013C pi bond and form a new C\u2013E bond (where\u00a0<strong>E<\/strong> is intended to represent a generic electrophile), generating a resonance-stabilized carbocation:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15878\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/3-explanation-of-why-och3-is-an-ortho-para-director-with-key-resonance-form-with-full-octets.gif\" alt=\"explanation of why och3 is an ortho para director with key resonance form with full octets\" width=\"630\" height=\"181\" \/><\/p>\n<p>If you look closely, you should note that we can form\u00a0<strong>four<\/strong> resonance forms . Three of them bear full carbocations (on C1, C3, and C5), but it is the the fourth one &#8211; the resonance form where there is a C=O pi bond &#8211; which is particularly important. Why?\u00a0<strong>\u00a0In this resonance form, all of the carbon atoms have a full octet of electrons.\u00a0<\/strong>That&#8217;s because the oxygen directly bonded to the ring can donate a lone pair to the adjacent carbocation, forming a pi bond. This is an example of <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/12\/15\/exploring-resonance-pi-donation\/\">pi donation<\/a>.<\/p>\n<p>Here&#8217;s the pathway for attack of the electrophile at the <em>meta-<\/em>\u00a0position. Note the difference!<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15879\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/4-resonance-forms-for-meta-attack-in-electrophilic-aromatic-substitution-of-ortho-para-director.gif\" alt=\"resonance forms for meta attack in electrophilic aromatic substitution of ortho para director\" width=\"630\" height=\"147\" \/><\/p>\n<p>Attack of the electrophile at C-3 results in a carbocation which can be delocalized <em>via<\/em> resonance to C2, C4, and C6. However, there&#8217;s no way to &#8220;move&#8221; the carbocation to C1, which means that there&#8217;s no reasonable resonance form where all atoms have full octets.<\/p>\n<p>This makes the\u00a0<em>meta-\u00a0<\/em>carbocation intermediate much <strong>less<\/strong> stable than the\u00a0<em>ortho-\u00a0<\/em>carbocation intermediate.<\/p>\n<p>Finally, here is the reaction leading to the <em>para-<\/em>\u00a0product:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15880\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/5-resonance-forms-showing-para-attack-on-anisole-with-key-resonance-form-full-octets.gif\" alt=\"resonance forms showing para attack on anisole with key resonance form full octets\" width=\"630\" height=\"236\" \/><\/p>\n<p>Here we can again draw resonance forms with carbocations on C1, C3, and C5, as well as a fourth resonance form where the attached oxygen atom donates an electron pair to the carbocation on C1,\u00a0 resulting in a full octet at carbon. This is a situation essentially the same as the\u00a0<em>ortho-<\/em> intermediate.<\/p>\n<p>So, by analysis of the resonance forms\u00a0 (<em>and mark my word, you may well be asked to do the same on a test in the near future)\u00a0<\/em>we can see that the intermediate carbocations resulting from\u00a0<em>ortho-\u00a0<\/em>and\u00a0<em>para<\/em>&#8211; addition are considerably more stable than the intermediate from\u00a0<em>meta<\/em>&#8211; addition.<\/p>\n<p>This explains is why\u00a0<em>ortho-\u00a0<\/em>and\u00a0<em>para-<\/em> products dominate, and the\u00a0<em>meta-<\/em> product is minor. [<a href=\"#notetwo\">Note 2<\/a>]<\/p>\n<p>It might be helpful to visualize this by drawing a reaction energy diagram.<\/p>\n<h2><a id=\"four\"><\/a>4. The Reaction-Energy Diagram For An Ortho Para Director<\/h2>\n<p>The transition state leading to the\u00a0<em>ortho-\u00a0<\/em>and <i>para-\u00a0<\/i>addition products is much lower in energy than the\u00a0<em>meta<\/em>&#8211; .<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15881\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/6-reaction-energy-diagram-for-an-ortho-para-director-where-para-is-least-energy-ortho-slightly-higher-and-meta-is-highest.gif\" alt=\"reaction energy diagram for an ortho para director where para is least energy ortho slightly higher and meta is highest\" width=\"600\" height=\"347\" \/><\/p>\n<p>One question &#8211; why do you think that\u00a0\u00a0<em>para-<\/em> might be favored (e.g. 60%-70%\u00a0 yield for the\u00a0<em>para<\/em>&#8211; product of nitration, above, versus 30-40% for <em>ortho-<\/em>) even though there are two <em>ortho-<\/em> positions and only one\u00a0<em>para-\u00a0<\/em>?<\/p>\n<p>Think about that for a minute, and we&#8217;ll address it below.<\/p>\n<h2><a id=\"five\"><\/a>5. Case Study #2: A <i>meta-\u00a0<\/i>director (CF<sub>3<\/sub>).<\/h2>\n<p>So what about CF<sub>3<\/sub>? Why does it give <em>meta-\u00a0<\/em>products? Let&#8217;s do the same type of analysis.<\/p>\n<p>Here&#8217;s the pathway leading to the <em>ortho-<\/em>\u00a0product. As with the\u00a0<em>ortho-\u00a0<\/em>intermediate above, we can draw three resonance forms placing the carbocation on C1, C3, and C5, respectively.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15882\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/7-resonance-forms-for-ortho-attack-on-trifluoromethyl-benzene.gif\" alt=\"resonance forms for ortho attack on trifluoromethyl benzene\" width=\"630\" height=\"180\" \/><\/p>\n<p>So what&#8217;s different in this case?<\/p>\n<p>What&#8217;s different is the presence of a strong electron withdrawing group (CF<sub>3<\/sub>) at C1, and this completely changes the ballgame.<\/p>\n<p>As we&#8217;ve <a href=\"https:\/\/www.masterorganicchemistry.com\/2011\/03\/21\/three-factors-that-destabilize-carbocations\/\">said<\/a>, carbocations are\u00a0<em>destabilized\u00a0<\/em>by neighbors which withdraw electron-density. Therefore we would expect this to be a very <strong>minor<\/strong> resonance contributor, with the result that the positive charge is only delocalized over C3 and C5.<\/p>\n<p><span style=\"color: #993366;\"><em>[<strong>Note<\/strong>: I&#8217;m avoiding saying that this is a &#8220;less stable&#8221; resonance form, because I want you to remember that <span style=\"text-decoration: underline;\">resonance forms don&#8217;t really exist<\/span>. What does exist is the resonance &#8220;hybrid&#8221;, which is built up of contributions from each of the resonance forms. You won&#8217;t be struck down by lightning if you refer to &#8220;more stable&#8221; or &#8220;less stable&#8221; resonance forms in casual conversation, so long as you always keep the &#8220;imaginary&#8221; nature of resonance forms in mind].<\/em><\/span><\/p>\n<p>We&#8217;ve noted that CF<sub>3<\/sub> is a\u00a0<em>meta-<\/em> director. It&#8217;s reasonable to think that there&#8217;s something about the <em>meta<\/em>&#8211; that makes it particularly stable.\u00a0By\u00a0analyzing the intermediate for the <em>meta<\/em>&#8211; product below, can you see why?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15883\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/8-resonance-forms-for-meta-attack-on-trifluoromethyl-benzene.gif\" alt=\"resonance forms for meta attack on trifluoromethyl benzene\" width=\"630\" height=\"180\" \/><\/p>\n<p>Hmmm.\u00a0 There&#8217;s no intermediate where a carbon has a full octet. There are no particularly\u00a0<em>stable<\/em> resonance forms.<\/p>\n<p>It&#8217;s kind of &#8220;meh&#8221;, isn&#8217;t it?<\/p>\n<h2><a id=\"six\"><\/a>6. What We Call &#8220;<em>meta<\/em>&#8211; Directors&#8221; Are More Like &#8220;<em>ortho<\/em>-, <em>para<\/em>&#8211; Avoiders&#8221;<\/h2>\n<p>On the other hand, there aren&#8217;t any particularly\u00a0<em>unstable\u00a0<\/em>resonance forms either. Since the positive charge is localized on C2, C4, and C6, a situation where the positive charge is directly adjacent to the electron-withdrawing CF<sub>3<\/sub> group is avoided.\u00a0 And the positive charge is thus delocalized nicely throughout the ring, unlike in the\u00a0<em>ortho-\u00a0<\/em>situation, above.<\/p>\n<p>So it&#8217;s a &#8220;less bad&#8221; intermediate than the\u00a0<em>ortho-.\u00a0<\/em><\/p>\n<p>Finally, the\u00a0<em>para-\u00a0<\/em>intermediate has the same problem as the\u00a0<em>ortho-\u00a0<\/em>; an intermediate with a positive charge on C1, adjacent to the CF<sub>3<\/sub>.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15884\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/9-resonance-forms-for-para-attack-on-trifluoromethyl-benzene.gif\" alt=\"resonance forms for para attack on trifluoromethyl benzene\" width=\"630\" height=\"226\" \/><\/p>\n<p>This results in only <em>two<\/em> important resonance forms, which leads to a less delocalized (and therefore less stable) carbocation intermediate.<\/p>\n<p>Bottom line:<strong>\u00a0\u00a0the\u00a0<em>meta <\/em>carbocation\u00a0intermediate is more stable than either the\u00a0<em>ortho<\/em>&#8211; or the\u00a0<em>para-\u00a0 <\/em>intermediates.<\/strong><\/p>\n<p>But it&#8217;s not because the substituent itself has any stabilizing effect on the <em>meta<\/em>&#8211; intermediate. [And as we&#8217;ve seen, all\u00a0<em>meta-\u00a0<\/em>directing substituents are\u00a0<strong>deactivating<\/strong>, meaning that they decrease the rate of reaction relative to H].<\/p>\n<p>I&#8217;d argue that it&#8217;s more helpful to think of the <em>meta-\u00a0<\/em>as\u00a0<em>less unstable\u00a0<\/em>than\u00a0the\u00a0<em>ortho-\u00a0<\/em>and\u00a0<em>para<\/em>&#8211; .<\/p>\n<p>In this way, it&#8217;s not so much that CF<sub>3<\/sub> is a <em>meta-<\/em>\u00a0director, so much that it is an<strong><em>\u00a0&#8220;ortho<\/em>&#8211; ,\u00a0<em>para<\/em>&#8211; avoider. &#8220;<\/strong><\/p>\n<h2><a id=\"seven\"><\/a>7. The Reaction Energy Diagram For A\u00a0<em>meta-\u00a0<\/em>Director<\/h2>\n<p>Here&#8217;s a sketch of the reaction energy diagram:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15885\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/10-reaction-energy-diagram-for-meta-director-shows-meta-slightly-lower-energy-than-ortho-and-para.gif\" alt=\"reaction energy diagram for meta director shows meta slightly lower energy than ortho and para\" width=\"600\" height=\"269\" \/><\/p>\n<p>Alright.<\/p>\n<p>Back to our original question. So which carbocation is more stable?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-15886\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/11-which-carbocation-is-most-stable-question-och3-stabilizes-through-pi-donation-also-ch3-much-more-electron-releasing-than-cf3.gif\" alt=\"which carbocation is most stable question - och3 stabilizes through pi donation also ch3 much more electron releasing than cf3\" width=\"600\" height=\"226\" \/><\/p>\n<p>Clearly, the carbocation with an adjacent oxygen bearing a lone pair is\u00a0<em>far<\/em> more stable than a carbocation adjacent to an electron-withdrawing group like CF<sub>3<\/sub>.<\/p>\n<p>And that comprises the difference between an\u00a0<em>ortho-, para-\u00a0<\/em>director like OCH<sub>3<\/sub> and a\u00a0<em>meta-\u00a0<\/em>director like CF<sub>3<\/sub>.<\/p>\n<p>It&#8217;s worth noting that most alkyl groups (such as CH<sub>3<\/sub>\u00a0) lack a lone pair, but are still\u00a0\u00a0<em>ortho-, para-\u00a0<\/em>directors. This is consistent with everything we&#8217;ve learned before about how alkyl groups are generally stabilizing for carbocations- recall that carbocation stability generally increases with substitution [primary (least stable) &lt; secondary &lt; tertiary (most stable). ]<\/p>\n<p><strong>So about those\u00a0<em>para<\/em>&#8211; products&#8230;\u00a0<\/strong><\/p>\n<p>Why are\u00a0<em>para-\u00a0<\/em>products produced at a greater rate than\u00a0<em>ortho-\u00a0<\/em>?<\/p>\n<p>The answer is <strong>steric hindrance.\u00a0<\/strong><\/p>\n<p>Attack at the\u00a0<em>para<\/em> position is less encumbered by the substituent than attack at the\u00a0<em>ortho-<\/em> positions are.<\/p>\n<h2><strong><a id=\"eight\"><\/a>8. So Why Are Halogens Ortho-, Para- Directors?<\/strong><\/h2>\n<p>This leaves us with the somewhat tricky example of halogens.<\/p>\n<p>Why are fluorine, chlorine, bromine, and iodine <em>ortho-, para-\u00a0<\/em>directors even though they are deactivating groups?<\/p>\n<p>The answer should come as no surprise if you&#8217;ve been following along, but we&#8217;re going to leave this until the next post, because this one is long enough already.<\/p>\n<p>Next post: <a href=\"https:\/\/www.masterorganicchemistry.com\/2018\/03\/05\/why-are-halogens-ortho-para-directors\/\"><strong>Why are halogens ortho-, para- directors?<\/strong><\/a><\/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\/2018\/03\/05\/why-are-halogens-ortho-para-directors\/\" class=\"\"><span>Why are halogens ortho- para- directors?<\/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\/2018\/04\/18\/electrophilic-aromatic-substitutions-1-halogenation\/\" class=\"\"><span>Electrophilic Aromatic Substitutions (1) \u2013 Halogenation of Benzene<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2018\/04\/30\/electrophilic-aromatic-substitutions-2-nitration-and-sulfonation\/\" class=\"\"><span>Electrophilic Aromatic Substitutions (2) \u2013 Nitration and Sulfonation<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2018\/05\/17\/friedel-crafts-alkylation-acylation\/\" class=\"\"><span>EAS Reactions (3) \u2013 Friedel-Crafts Acylation and Friedel-Crafts Alkylation<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/organic-chemistry-practice-problems\/electrophilic-aromatic-substitution-practice-problems\/\" class=\"\"><span>Electrophilic Aromatic Substitution Practice Problems (MOC Membership)<\/span><\/a><\/li><li><a href=\"https:\/\/www.masterorganicchemistry.com\/2017\/07\/11\/electrophilic-aromatic-substitution-introduction\/\" class=\"\"><span>Electrophilic Aromatic Substitution: Introduction<\/span><\/a><\/li><\/ul><\/div>\n<p><a id=\"noteone\"><\/a><strong>Note 1<\/strong>. Or <a href=\"https:\/\/en.wikipedia.org\/wiki\/Hyperconjugation\">hyperconjugation<\/a>, which most textbooks (with the notable exception of Maitland Jones) generally avoid.<\/p>\n<p><a id=\"notetwo\"><\/a><strong>Note 2<\/strong>. It&#8217;s more correct to say that <em>ortho-<\/em>\u00a0and <em>para-<\/em>\u00a0products dominate because the <strong>transition states<\/strong> leading to these products are lower in energy, rather than the energies of the intermediates themselves. After all, it&#8217;s the energy of the transition states which determines the activation barrier, and therefore the reaction rate.<\/p>\n<p><strong><a id=\"notethree\"><\/a>Note 3.\u00a0<\/strong>Useful table with yields of\u00a0<em>meta<\/em>&#8211; products for various substituted benzenes:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-39263\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2025\/02\/F1-Table-of-Meta-directors-table-showing-amount-of-meta-product-obtained-via-nitration-of-various-meta-directors-from-ingold-2nd-edition.gif\" alt=\"Table of Meta directors - table showing amount of meta product obtained via nitration of various meta directors from ingold 2nd edition\" width=\"640\" height=\"898\" \/><\/a><\/p>\n<hr \/>\n<h2><a id=\"quiz\"><\/a>Quiz Yourself!<\/h2>\n<p><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3677-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3675-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3676-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3275-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/2908-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0509-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0510-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0511-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/0512-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><br \/>\n<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-36214 aligncenter\" src=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/quiz-previews\/3261-Front-Image-Only.png\" alt=\"\" width=\"600\" height=\"450\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.masterorganicchemistry.com\/moc-membership\/\"><strong>Become a MOC member<\/strong><\/a> to see the clickable quiz with answers on the back.<\/p>\n<p><\/p>\n<hr \/>\n<h2><a id=\"references\"><\/a>(Advanced) References and Further Reading<\/h2>\n<ol>\n<li><strong> A. F. Holleman, Die direkte Einf\u00fchrung von Substituenten in den Benzolkern<br \/>\n<\/strong><em>Rec. Trav. Chim. Pays-Bas<\/em> <strong>1910<\/strong>, <em>12<\/em>, 455-456<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/abs\/10.1002\/recl.19100291205\">10.1002\/recl.19100291205<\/a><br \/>\nA.F Holleman from 1910 said that <em>ortho<\/em>&#8211;<em>para<\/em> orientation is associated with activation and meta orientation with deactivation.<\/li>\n<li><strong>\u2014The nature of the alternating effect in carbon chains. Part XXIII. Anomalous orientation by halogens, and its bearing on the problem of the ortho\u2013para ratio, in aromatic substitution<br \/>\n<\/strong>Christopher Kelk Ingold and Charles Cyril Norrey Vass<strong><br \/>\n<\/strong><em>J. Chem. Soc.<\/em> <strong>1928<\/strong>, 417-425<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/Content\/ArticleLanding\/JR\/1928\/JR9280000417#!divAbstract\">10.1039\/JR9280000417<\/a><br \/>\nThis paper discusses directing effects in 1,2-dihalobenzenes.<\/li>\n<li><strong> Some observations concerning steric hindrance and the effects of substituents on the ortho : para ratio in aromatic substitution<br \/>\n<\/strong>P. B. D. de la Mare<strong><br \/>\n<\/strong><em>J. Chem. Soc.<\/em><strong> 1949<\/strong>, 2871-2874<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1949\/JR\/JR9490002871#!divAbstract\">10.1039\/JR9490002871<\/a><br \/>\nIn this paper, de la Mare discusses various factors that may account for a predominance of <em>para<\/em> over <em>ortho<\/em> selectivity, after dividing the yield of <em>ortho<\/em> product by 2 (since there are 2 <em>ortho<\/em> positions but only 1 <em>para<\/em> position in monosubstituted benzenes).<\/li>\n<li><strong> Volume effects of alkyl groups in aromatic compounds. Part V. The monosulphonation of p-cymene<br \/>\n<\/strong>R. J. W. Le F\u00e8vre<strong><br \/>\n<\/strong><em>J. Chem. Soc.<\/em><strong> 1934, <\/strong>1501-1502<br \/>\n<strong>DOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1934\/jr\/jr9340001501#!divAbstract\">10.1039\/JR9340001501<\/a><br \/>\nIn <em>p<\/em>-cymene, the major product obtained upon electrophilic sulfonation is the 2-product (<em>ortho<\/em> to the methyl group), likely due to sterics.<\/li>\n<li><strong>Effects of Alkyl Groups in Electrophilic Additions and Substitutions<br \/>\n<\/strong>COHN, H., HUGHES, E., JONES, M. and PEELING, M. G.<strong><br \/>\n<\/strong><em>Nature <\/em><strong>1952, <\/strong><em>169<\/em>, 291<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/www.nature.com\/articles\/169291a0\">1038\/169291a0<\/a><br \/>\nThis paper has data comparing the nitration of <em>t<\/em>-butylbenzene and toluene. <em>T<\/em>-butylbenzene is much more <em>p<\/em>-directing than toluene (79.5% <em>para<\/em> for t-butylbenzene vs. 40% <em>para<\/em> for toluene), which is likely due to sterics (<em>ortho<\/em> approach is blocked by the bulkier t-butyl group).<\/li>\n<li><strong>Distribution of Isomers in the Mononitration of Ethyl- and Isopropylbenzene. Further Evidence for a Steric Effect in Isomer Distribution<\/strong><br \/>\nHerbert C. Brown and W. Hallam Bonner<br \/>\n<em>Journal of the American Chemical Society<\/em> <strong>1954,<\/strong> <em>76<\/em> (2), 605-606<br \/>\n<strong>DOI<\/strong>: <a href=\"https:\/\/pubs.acs.org\/doi\/abs\/10.1021\/ja01631a084\">10.1021\/ja01631a084<\/a><br \/>\nTable II in this paper illustrates that the <em>ortho<\/em> product obtained from nitration of monoalkylbenzenes decreases as the alkyl group gets larger (e.g. t-butylbenzene yields very little <em>ortho<\/em> product upon nitration compared to toluene).<\/li>\n<li><strong>\u2014The nature of the alternating effect in carbon chains. Part XXII. An attempt further to define the probable mechanism of orientation in aromatic substitution<br \/>\n<\/strong>Christopher Kelk Ingold and Florence Ruth Shaw<strong><br \/>\n<\/strong><em>J. Chem. Soc.<\/em><strong> 1927, <\/strong>2918-2926<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1927\/JR\/JR9270002918#!divAbstract\">10.1039\/JR9270002918<\/a><br \/>\nAn early paper by the influential Physical Organic Chemist, Prof. C. K. Ingold, stating that halogenobenzenes are inductively electron-withdrawing but simultaneously resonance-stabilizing.<\/li>\n<li><strong>The Anomalous Reactivity of Fluorobenzene in Electrophilic Aromatic Substitution and Related Phenomena<br \/>\n<\/strong>Joel Rosenthal and David I. Schuster<strong><br \/>\n<\/strong><em>Journal of Chemical Education<\/em><strong> 2003, <\/strong><em>80<\/em> (6), 679<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.acs.org\/doi\/10.1021\/ed080p679\">1021\/ed080p679<\/a><br \/>\nA very interesting paper, suitable for curious undergrads, and discusses something that most practicing organic chemists will know empirically \u2013 fluorobenzene is almost as reactive as benzene in EAS or Friedel-Crafts reactions, which is counterintuitive when one considers electronic effects!<\/li>\n<li><strong>Organic chemistry<br \/>\n<\/strong> N. Haworth, C. K. Ingold, T. A. Henry<strong><br \/>\n<\/strong><em>Ann. Rep. Prog. Chem.<\/em><strong> 1926, <\/strong><em>23<\/em>, 74-185<strong><br \/>\nDOI: <\/strong><a href=\"https:\/\/pubs.rsc.org\/en\/content\/articlelanding\/1926\/ar\/ar9262300074#!divAbstract\">10.1039\/AR9262300074<\/a><strong><br \/>\n<\/strong>An early paper discussing directing effects in EAS. Pp. 136 and 137 contain figures that depict the flow of electrons. Pg. 140 discusses <em>meta<\/em>-direction, which occurs for the \u2018opposite\u2019 reasons as <em>o\/p<\/em>-direction by alkyl groups.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Ortho-, Para&#8211; and Meta&#8211; Directors In Electrophilic Aromatic Substitution (EAS), some substituents on benzene will direct the electrophile\u00a0E to the\u00a0ortho&#8211; (1,2)and para&#8211; (1,4) positions. These <\/p>\n","protected":false},"author":1,"featured_media":15875,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1297],"tags":[1298,332,1303,1302,319,1301,1231,1299,1300,1286],"post_folder":[],"class_list":["post-11291","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-aromatic-reactions","tag-activating","tag-carbocation-stability","tag-deactivating","tag-directing-groups","tag-electrophilic-aromatic-substitution","tag-meta","tag-nitration","tag-ortho","tag-para","tag-reaction-energy-diagram"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry<\/title>\n<meta name=\"description\" content=\"Why some groups are ortho-, para- directors and others are meta- directors (more like &quot;ortho, para avoiders&quot;) :-) It&#039;s all about carbocation stability.\" \/>\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\/2018\/02\/02\/understanding-ortho-para-meta-directors\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry\" \/>\n<meta property=\"og:description\" content=\"Why some groups are ortho-, para- directors and others are meta- directors (more like &quot;ortho, para avoiders&quot;) :-) It&#039;s all about carbocation stability.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/\" \/>\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=\"2018-02-02T12:00:30+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-04-22T17:35:30+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\" \/>\n\t<meta property=\"og:image:width\" content=\"1008\" \/>\n\t<meta property=\"og:image:height\" content=\"846\" \/>\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=\"16 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/\"},\"author\":{\"name\":\"James Ashenhurst\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#\\\/schema\\\/person\\\/78d83ec7d02b4b7365bade2cedaef80c\"},\"headline\":\"Understanding Ortho, Para, and Meta Directors\",\"datePublished\":\"2018-02-02T12:00:30+00:00\",\"dateModified\":\"2026-04-22T17:35:30+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/\"},\"wordCount\":2638,\"commentCount\":20,\"publisher\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\",\"keywords\":[\"activating\",\"carbocation stability\",\"deactivating\",\"directing groups\",\"electrophilic aromatic substitution\",\"meta\",\"nitration\",\"ortho\",\"para\",\"reaction energy diagram\"],\"articleSection\":[\"Reactions of Aromatic Molecules\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/\",\"name\":\"Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\",\"datePublished\":\"2018-02-02T12:00:30+00:00\",\"dateModified\":\"2026-04-22T17:35:30+00:00\",\"description\":\"Why some groups are ortho-, para- directors and others are meta- directors (more like \\\"ortho, para avoiders\\\") :-) It's all about carbocation stability.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\",\"contentUrl\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/wp-content\\\/uploads\\\/2019\\\/12\\\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif\",\"width\":1008,\"height\":846,\"caption\":\"summary of ortho meta and para directors explanation with resonance structures pi donors and pi acceptors\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/2018\\\/02\\\/02\\\/understanding-ortho-para-meta-directors\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.masterorganicchemistry.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Understanding Ortho, Para, and Meta Directors\"}]},{\"@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":"Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry","description":"Why some groups are ortho-, para- directors and others are meta- directors (more like \"ortho, para avoiders\") :-) It's all about carbocation stability.","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\/2018\/02\/02\/understanding-ortho-para-meta-directors\/","og_locale":"en_US","og_type":"article","og_title":"Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry","og_description":"Why some groups are ortho-, para- directors and others are meta- directors (more like \"ortho, para avoiders\") :-) It's all about carbocation stability.","og_url":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/","og_site_name":"Master Organic Chemistry","article_publisher":"https:\/\/www.facebook.com\/Master-Organic-Chemistry-242610599108055\/","article_published_time":"2018-02-02T12:00:30+00:00","article_modified_time":"2026-04-22T17:35:30+00:00","og_image":[{"width":1008,"height":846,"url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif","type":"image\/gif"}],"author":"James Ashenhurst","twitter_card":"summary_large_image","twitter_misc":{"Written by":"James Ashenhurst","Est. reading time":"16 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#article","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/"},"author":{"name":"James Ashenhurst","@id":"https:\/\/www.masterorganicchemistry.com\/#\/schema\/person\/78d83ec7d02b4b7365bade2cedaef80c"},"headline":"Understanding Ortho, Para, and Meta Directors","datePublished":"2018-02-02T12:00:30+00:00","dateModified":"2026-04-22T17:35:30+00:00","mainEntityOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/"},"wordCount":2638,"commentCount":20,"publisher":{"@id":"https:\/\/www.masterorganicchemistry.com\/#organization"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif","keywords":["activating","carbocation stability","deactivating","directing groups","electrophilic aromatic substitution","meta","nitration","ortho","para","reaction energy diagram"],"articleSection":["Reactions of Aromatic Molecules"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/","url":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/","name":"Understanding Ortho, Para, and Meta Directors - Master Organic Chemistry","isPartOf":{"@id":"https:\/\/www.masterorganicchemistry.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#primaryimage"},"image":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#primaryimage"},"thumbnailUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif","datePublished":"2018-02-02T12:00:30+00:00","dateModified":"2026-04-22T17:35:30+00:00","description":"Why some groups are ortho-, para- directors and others are meta- directors (more like \"ortho, para avoiders\") :-) It's all about carbocation stability.","breadcrumb":{"@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#primaryimage","url":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif","contentUrl":"https:\/\/www.masterorganicchemistry.com\/wp-content\/uploads\/2019\/12\/0-summary-of-ortho-meta-and-para-directors-explanation-with-resonance-structures-pi-donors-and-pi-acceptors.gif","width":1008,"height":846,"caption":"summary of ortho meta and para directors explanation with resonance structures pi donors and pi acceptors"},{"@type":"BreadcrumbList","@id":"https:\/\/www.masterorganicchemistry.com\/2018\/02\/02\/understanding-ortho-para-meta-directors\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.masterorganicchemistry.com\/"},{"@type":"ListItem","position":2,"name":"Understanding Ortho, Para, and Meta Directors"}]},{"@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\/11291","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=11291"}],"version-history":[{"count":0,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/posts\/11291\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media\/15875"}],"wp:attachment":[{"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/media?parent=11291"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/categories?post=11291"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/tags?post=11291"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.masterorganicchemistry.com\/wp-json\/wp\/v2\/post_folder?post=11291"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}