{"id":2973,"date":"2010-12-07T18:16:20","date_gmt":"2010-12-07T17:16:20","guid":{"rendered":"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973"},"modified":"2011-11-19T09:04:06","modified_gmt":"2011-11-19T09:04:06","slug":"antiaromaticity-avoided-a-tutorial-example","status":"publish","type":"post","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973","title":{"rendered":"(anti)aromaticity avoided: a tutorial example"},"content":{"rendered":"<div class=\"kcite-section\" kcite-section-id=\"2973\">\n<p>More inspiration from tutorials. In a lecture on organic aromaticity, the 4n+2\/4n H\u00fcckel rule was introduced (in fact, neither rule appears to have actually been coined in this form by H\u00fcckel himself!). The simplest examples are respectively the cyclopropenyl cation and anion. The former has 2 \u03c0-electrons exhibiting cyclic delocalisation, and the 4n+2 (n=0) rule predicts aromaticity. Accordingly, all three C-C distances <a href=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=485\" target=\"_blank\">are the same<\/a> (<a href=\"http:\/\/hdl.handle.net\/10042\/to-6083\" target=\"_blank\">1.363\u00c5<\/a>).<\/p>\n<div id=\"attachment_2974\" style=\"width: 201px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2974\" class=\"size-full wp-image-2974\" title=\"cyclopropenium\" src=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium.jpg\" alt=\"\" width=\"191\" height=\"131\" srcset=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium.jpg 572w, https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-300x206.jpg 300w\" sizes=\"auto, (max-width: 191px) 100vw, 191px\" \/><\/a><p id=\"caption-attachment-2974\" class=\"wp-caption-text\">Cyclopropenium cation and anion<\/p><\/div>\n<p>The anion however appears to have 4 \u03c0-electrons, and must therefore belong to the 4n (n=1) rule and exhibit antiaromaticity. Pretty straight forward thus far. But students have a knack of asking apparently simple, but quite thought provoking questions. This one was &#8220;<em>does one count lone pairs of electrons<\/em>&#8220;? Perhaps a different way of putting it would be &#8220;<em>does the lone pair really count as \u03c0-electrons<\/em>?&#8221;<\/p>\n<p>So, time for a calculation. Well, it turns out there are two isomers of the anion. The <a href=\"http:\/\/hdl.handle.net\/10042\/to-6077\" target=\"_blank\">first<\/a> has two C-C bond lengths of 1.383\u00c5 and one of 1.841\u00c5; two short and one (very) long. Moreover, the whole system is very much non planar.<\/p>\n<div id=\"attachment_2976\" style=\"width: 272px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-b.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2976\" class=\"size-full wp-image-2976\" title=\"cyclopropenium-b\" src=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-b.jpg\" alt=\"\" width=\"262\" height=\"243\" srcset=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-b.jpg 782w, https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-b-300x279.jpg 300w\" sizes=\"auto, (max-width: 262px) 100vw, 262px\" \/><\/a><p id=\"caption-attachment-2976\" class=\"wp-caption-text\">Cyclopropenium anion, first isomer<\/p><\/div>\n<p>This isomer turns out to be really a 4\u03c0-allyl anion in disguise. To avoid any danger of cyclic conjugation (and hence antiaromaticity), the groups at the end of the allyl fragment rotate. So yes, this <strong>IS<\/strong> a 4\u03c0-electron system, but the molecule has cleverly distorted to avoid antiaromaticity as best it can.<\/p>\n<div id=\"attachment_2978\" style=\"width: 270px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-a1.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2978\" class=\"size-full wp-image-2978\" title=\"cyclopropenium-a\" src=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-a1.jpg\" alt=\"\" width=\"260\" height=\"234\" srcset=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-a1.jpg 779w, https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium-a1-300x270.jpg 300w\" sizes=\"auto, (max-width: 260px) 100vw, 260px\" \/><\/a><p id=\"caption-attachment-2978\" class=\"wp-caption-text\">Cyclopropenium anion. Isomer 2.<\/p><\/div>\n<p>What about the second isomer?\u00a0<a href=\"http:\/\/hdl.handle.net\/10042\/to-6080\" target=\"_blank\">This now<\/a> has one short (1.293\u00c5) and two long (1.598\u00c5) C-C lengths. The carbon bearing the two long bonds is now highly non planar. It is best described as an isolated double bond (2 \u03c0-electrons) trying to get as far away as possible, and to avoid as much overlap as it can, with a lone pair (NOT \u03c0) on the third carbon. Now, the lone pair really does NOT count, since it is too far from the other 2 \u03c0-electrons, and inclined at the wrong angle, to overlap effectively with them. The two isomers are almost the same in energy (the first being the lower in free energy by ~1 kcal\/mol).<\/p>\n<p>So what kind of answer would one give to the inquisitive tutee? Firstly, as the name implies, antiaromaticity is not good for a molecule. If it possibly can, it will avoid it. For the cyclopropenium anion, there are two quite effective ways of avoiding antiaromaticity. It is not, as a result, actually a good example of an antiaromatic system. Because molecules can be very clever at avoiding antiaromaticity, remarkably f<a href=\"http:\/\/dx.doi.org\/10.1021\/ol703129z\" target=\"_blank\">ew examples<\/a> of genuine antiaromatics actually exist!<\/p>\n<p>I end with another way of looking at this problem using group theory. The cyclopropenium cation has D<sub>3h<\/sub> symmetry, and the LUMO (lowest unoccupied) molecule orbital in fact belongs to the <strong>E&#8221;<\/strong> irreducible representation. This means it is doubly degenerate. To form the anion from it, two electrons must be placed in one of these orbitals (but unless an open shell is formed, one cannot place one electron in each). Whichever orbital receives the two electrons is now stabilised, the degeneracy must break, and the resulting geometry must reflect this. The two symmetry-broken geometries are precisely those shown above.<\/p>\n<table border=\"0\">\n<tbody>\n<tr>\n<td><div id=\"attachment_2989\" style=\"width: 246px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2989\" class=\"size-full wp-image-2989\" title=\"cat11\" onclick=\"jmolInitialize('..\/Jmol\/');jmolSetAppletColor('white');jmolApplet([450,450],'load wp-content\/uploads\/2010\/12\/cp11_0.02.jvxl;isosurface &quot;&quot; translucent;zoom 100;spin 3;');\" src=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat111.jpg\" alt=\"\" width=\"236\" height=\"200\" srcset=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat111.jpg 334w, https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat111-300x254.jpg 300w\" sizes=\"auto, (max-width: 236px) 100vw, 236px\" \/><p id=\"caption-attachment-2989\" class=\"wp-caption-text\">Cyclopropenium cation, E&quot; LUMO orbital 11. Click for 3D<\/p><\/div><\/td>\n<td><div id=\"attachment_2990\" style=\"width: 192px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2990\" class=\"size-full wp-image-2990\" title=\"cat12\" onclick=\"jmolInitialize('..\/Jmol\/');jmolSetAppletColor('white');jmolApplet([450,450],'load wp-content\/uploads\/2010\/12\/cp12_0.02.jvxl;isosurface &quot;&quot; translucent;zoom 100;spin 3;');\" src=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat121.jpg\" alt=\"\" width=\"182\" height=\"200\" srcset=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat121.jpg 296w, https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cat121-273x300.jpg 273w\" sizes=\"auto, (max-width: 182px) 100vw, 182px\" \/><p id=\"caption-attachment-2990\" class=\"wp-caption-text\">Cyclopropenium cation,  E&quot; LUMO orbital 12. Click for 3D<\/p><\/div><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- kcite active, but no citations found -->\n<\/div> <!-- kcite-section 2973 -->","protected":false},"excerpt":{"rendered":"<p>More inspiration from tutorials. In a lecture on organic aromaticity, the 4n+2\/4n H\u00fcckel rule was introduced (in fact, neither rule appears to have actually been coined in this form by H\u00fcckel himself!). The simplest examples are respectively the cyclopropenyl cation and anion. The former has 2 \u03c0-electrons exhibiting cyclic delocalisation, and the 4n+2 (n=0) rule [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":5,"activitypub_interaction_policy_quote":"anyone","activitypub_status":"","footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[4],"tags":[24,40,346,2648,345,373],"ppma_author":[2661],"class_list":["post-2973","post","type-post","status-publish","format-standard","hentry","category-interesting-chemistry","tag-energy","tag-free-energy","tag-huckel","tag-interesting-chemistry","tag-pretty-straight-forward","tag-tutorial-material"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>(anti)aromaticity avoided: a tutorial example - Henry Rzepa&#039;s Blog<\/title>\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.ch.ic.ac.uk\/rzepa\/blog\/?p=2973\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"(anti)aromaticity avoided: a tutorial example - Henry Rzepa&#039;s Blog\" \/>\n<meta property=\"og:description\" content=\"More inspiration from tutorials. In a lecture on organic aromaticity, the 4n+2\/4n H\u00fcckel rule was introduced (in fact, neither rule appears to have actually been coined in this form by H\u00fcckel himself!). The simplest examples are respectively the cyclopropenyl cation and anion. 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In a lecture on organic aromaticity, the 4n+2\/4n H\u00fcckel rule was introduced (in fact, neither rule appears to have actually been coined in this form by H\u00fcckel himself!). The simplest examples are respectively the cyclopropenyl cation and anion. The former has 2 \u03c0-electrons exhibiting cyclic delocalisation, and the 4n+2 (n=0) rule [&hellip;]","og_url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973","og_site_name":"Henry Rzepa&#039;s Blog","article_published_time":"2010-12-07T17:16:20+00:00","article_modified_time":"2011-11-19T09:04:06+00:00","og_image":[{"url":"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium.jpg","type":"","width":"","height":""}],"author":"Henry Rzepa","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Henry Rzepa","Estimated reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973#article","isPartOf":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973"},"author":{"name":"Henry Rzepa","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#\/schema\/person\/2b40f7b9c872a4dc1547e040a11b6281"},"headline":"(anti)aromaticity avoided: a tutorial example","datePublished":"2010-12-07T17:16:20+00:00","dateModified":"2011-11-19T09:04:06+00:00","mainEntityOfPage":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973"},"wordCount":588,"commentCount":12,"image":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973#primaryimage"},"thumbnailUrl":"http:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2010\/12\/cyclopropenium.jpg","keywords":["energy","free energy","Huckel","Interesting chemistry","Pretty straight forward","Tutorial material"],"articleSection":["Interesting chemistry"],"inLanguage":"en-GB","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=2973","name":"(anti)aromaticity avoided: a tutorial example - 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The best known is the H\u00fcckel 4n+2 rule (n=0,1, etc) for inferring diatropic aromatic ring currents in singlet-state \u03c0-conjugated cyclic molecules\u2021 and a counter 4n rule which infers an antiaromatic paratropic ring current for the system.\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2022\/03\/C2B2-300x212.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":24974,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=24974","url_meta":{"origin":2973,"position":1},"title":"C2N2: a 10-electron four-atom molecule displaying both H\u00fcckel 4n+2 and Baird 4n selection rules for ring aromaticity.","author":"Henry Rzepa","date":"April 7, 2022","format":false,"excerpt":"The previous examples of four atom systems displaying two layers of aromaticity illustrated how 4 (B4), 8 (C4) and 12 (N4) valence electrons were partitioned into 4n+2 manifolds (respectively 2+2, 6+2 and 6+6). The triplet state molecule B2C2 with 6 electrons partitioned into 2\u03c0 and 4\u03c3 electrons, with the latter\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2022\/04\/CN-np-300x249.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":11450,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=11450","url_meta":{"origin":2973,"position":2},"title":"The NMR spectra of methano[10]annulene and its dianion. The diatropic\/paratropic inversion.","author":"Henry Rzepa","date":"October 26, 2013","format":false,"excerpt":"The 1H NMR spectrum of an aromatic molecule such as benzene is iconic; one learns that the unusual chemical shift of the protons (~\u03b4 7-8 ppm) is due to their deshielding by a diatropic ring current resulting from the circulation of six aromatic \u03c0-electrons following the H\u00fcckel 4n+2 rule. But\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"Click for  3D","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/10\/dianion.jpeg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":4893,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=4893","url_meta":{"origin":2973,"position":3},"title":"Some fun with no-go areas of chemistry: cyclobutadiene.","author":"Henry Rzepa","date":"September 18, 2011","format":false,"excerpt":"Organic chemistry has some no-go areas, where few molecules dare venture. One of them is described by a concept known as anti-aromaticity. Whereas aromatic molecules are favoured species, their anti-equivalent is avoided. I previously illustrated this (H\u00fcckel rule) with cyclopropenium anion. Now I take a look at cyclobutadiene, for which\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2011\/09\/cbdzw.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":9218,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=9218","url_meta":{"origin":2973,"position":4},"title":"Aromaticity in the benzidine-like \u03c0-complex formed from PhNHOPh.","author":"Henry Rzepa","date":"January 19, 2013","format":false,"excerpt":"The transient \u03c0-complex formed during the \"[5,5]\" sigmatropic rearrangement of protonated N,O-diphenyl hydroxylamine can be (formally) represented as below, namely the interaction of a six-\u03c0-electron aromatic ring (the phenoxide anion 2) with a\u00a0four-\u03c0-electron phenyl dication-anion pair 1. Can one analyse this interaction in terms of aromaticity? I showed previously that\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"pi-QTAIM","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/01\/pi-QTAIM.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":9556,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=9556","url_meta":{"origin":2973,"position":5},"title":"Linking numbers, and twist and writhe components for two extended porphyrins.","author":"Henry Rzepa","date":"February 17, 2013","format":false,"excerpt":"My last comment as\u00a0appended to the previous post\u00a0promised to analyse two so-called extended porphyrins for their topological descriptors. I start with the\u00a0C\u00e3lug\u00e3reanu\/Fuller theorem\u00a0 which decomposes the topology of a space curve into two components, its twist (Tw) and its writhe (Wr, this latter being the extent to which coiling of\u2026","rel":"","context":"In &quot;Interesting chemistry&quot;","block_context":{"text":"Interesting chemistry","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=4"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"jetpack_likes_enabled":false,"authors":[{"term_id":2661,"user_id":1,"is_guest":0,"slug":"admin","display_name":"Henry Rzepa","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/897b6740f7f599bca7942cdf7d7914af5988937ae0e3869ab09aebb87f26a731?s=96&d=blank&r=g","0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2973","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2973"}],"version-history":[{"count":0,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2973\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2973"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2973"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2973"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fppma_author&post=2973"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}