{"id":23319,"date":"2021-02-03T14:05:21","date_gmt":"2021-02-03T14:05:21","guid":{"rendered":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=23319"},"modified":"2021-02-05T18:28:33","modified_gmt":"2021-02-05T18:28:33","slug":"the-thermal-reactions-took-precisely-the-opposite-stereochemical-course-to-that-which-we-had-predicted-a-non-covalent-interaction-view-of-the-model","status":"publish","type":"post","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319","title":{"rendered":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model."},"content":{"rendered":"<div class=\"kcite-section\" kcite-section-id=\"23319\">\n<p>Another foray into one of the more famous anecdotal chemistry &#8220;models&#8221;, the analysis of which led directly to the formulation of the WoodWard-Hoffmann (stereochemical) rules for pericyclic reactions. <a href=\"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=23203\" target=\"_blank\" rel=\"noopener\">Previously<\/a>, I tried to produce a modern computer model of what Woodward might have had to hand when discovering that the stereochemical outcome of a key reaction in his vitamin B12 synthesis was opposite to that predicted using <a href=\"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=8761\" target=\"_blank\" rel=\"noopener\">his best model<\/a> of the reaction.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg\" alt=\"Vitamin B12 synthesis\" width=\"520&quot;\" \/><\/p>\n<p>Such computer models generate quite accurate 3D coordinates of the transition state for the reaction and this can be most simply analysed for finding <i>e.g.<\/i> steric clashes. These are when two atoms (mostly hydrogen) approach too close to one another. But we now know that in the region 1.9 &#8211; 2.4\u00c5 these close approaches can be attractive as well as repulsive and so distances alone are not the complete story. Here I analyse these models using a technique known as non-covalent-interactions (NCI). This is based on the electron density and its reduced density gradients<sup>&hearts;<\/sup> and it explores not merely simply distances between atoms but the non-bonded or weakly interacting <b>regions<\/b> of a molecule, generating a colour coded surface of interaction rather than pairwise distances. The colour coding goes from <strong><span style=\"color: #ff0000;\">red<\/span><\/strong> (strongly destabilising, or repulsive regions) to<span style=\"color: #0000ff;\"> blue<\/span> (stabilising or attractive regions), with <strong><span style=\"color: #00ff00;\">green<\/span><\/strong> representing weakly stabilising and <strong><span style=\"color: #ffff00;\">yellow<\/span><\/strong> weakly destabilising. It gives a much more rounded picture of the entire molecule.<\/p>\n<div id=\"attachment_23320\" style=\"width: 460px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-23320\" onclick=\"jmolApplet([600,500],'load wp-content\/uploads\/2021\/02\/ncs.xyz;isosurface wp-content\/uploads\/2021\/02\/ncs.jvxl;zoom 130;spin 3;','c1');\"  class=\"size-large wp-image-23320\" src=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2021\/02\/yes.jpg\" alt=\"\" width=\"450\" height=\"364\" \/><p id=\"caption-attachment-23320\" class=\"wp-caption-text\">Disrotatory TS for G to H, Click for 3D<\/p><\/div>\n<div id=\"attachment_23321\" style=\"width: 460px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-23321\" onclick=\"jmolApplet([600,500],'load wp-content\/uploads\/2021\/02\/ncs1.xyz;isosurface wp-content\/uploads\/2021\/02\/nci1.jvxl;zoom 130;spin -3;','c2');\"  class=\"size-large wp-image-23321\" src=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2021\/02\/no.jpg\" alt=\"\" width=\"450\" height=\"396\" \/><p id=\"caption-attachment-23321\" class=\"wp-caption-text\">Conrotatory &#8220;TS&#8221; for G to J, Click for 3D<\/p><\/div>\n<p>The NCI surfaces are shown above and are best expanded into a rotatable 3D model by clicking on either image. Regions of interest are shown with arrows. The region of the &#8220;steric\u00a0clash&#8221;\u00a0identified for the (thermal) transition state\u00a0G to H (the one actually found by experiment) can be seen with the arrow in the top right.<sup>&Dagger;<\/sup> It is colour coded light blue (attractive; note the very attractive dark blue for the O&#8230;HO hydrogen bond in the system), but it is immediately next to a yellow\/orange region (repulsive). This again reminds us that &#8220;stabilising&#8221; and &#8220;destabilizing&#8221; regions of a molecule can be adjacent to each other, something that physical models cannot convey.\u00a0The steric clash for the &#8220;transition state&#8221; G to J (in quotes because it is actually a transition state calculated for the excited triplet state and not the ground state) is indicated with the arrow, being a clash of two methyl groups. It is coded green, indicating weak NCI stabilization.<\/p>\n<p>So, in this analysis, steric clashes become more complex as indicators of reaction outcomes, since it is the overall balance of stabilisation and destabilisation that determines this. You might argue that Woodward would have found this modern analysis far too woolly to be useful in the sense he used, which is as an alert for the possibility of a new principle in organic reaction mechanisms and certainly a Nobel prize for his collaborator Hoffmann! <\/p>\n<hr \/>\n<p><sup>&Dagger;<\/sup>The region of the C-C bond which is forming in this transition state has a very non-standard electron density, to which this analysis cannot really be applied. So that region should be disregarded for the &#8220;non-covalent&#8221; analysis being done here. <sup>&hearts;<\/sup>Plots a reduced density isosurface, colour mapped with ABS(&rho;)*SIGN(&lambda;2), where &lambda;2 is the middle eigenvalue of the Hessian matrix of the electron density. A web page for generating such surfaces can be found at DOI: <a href=\"https:\/\/doi.org\/ftkt\">ftkt<\/a>.<\/p>\n<!-- kcite active, but no citations found -->\n<\/div> <!-- kcite-section 23319 -->","protected":false},"excerpt":{"rendered":"<p>Another foray into one of the more famous anecdotal chemistry &#8220;models&#8221;, the analysis of which led directly to the formulation of the WoodWard-Hoffmann (stereochemical) rules for pericyclic reactions. Previously, I tried to produce a modern computer model of what Woodward might have had to hand when discovering that the stereochemical outcome of a key reaction [&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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[565,559],"tags":[],"ppma_author":[2661],"class_list":["post-23319","post","type-post","status-publish","format-standard","hentry","category-historical","category-pericyclic"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model. - 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=23319\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model. - Henry Rzepa&#039;s Blog\" \/>\n<meta property=\"og:description\" content=\"Another foray into one of the more famous anecdotal chemistry &#8220;models&#8221;, the analysis of which led directly to the formulation of the WoodWard-Hoffmann (stereochemical) rules for pericyclic reactions. Previously, I tried to produce a modern computer model of what Woodward might have had to hand when discovering that the stereochemical outcome of a key reaction [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319\" \/>\n<meta property=\"og:site_name\" content=\"Henry Rzepa&#039;s Blog\" \/>\n<meta property=\"article:published_time\" content=\"2021-02-03T14:05:21+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2021-02-05T18:28:33+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg\" \/>\n<meta name=\"author\" content=\"Henry Rzepa\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Henry Rzepa\" \/>\n\t<meta name=\"twitter:label2\" content=\"Estimated reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model. - Henry Rzepa&#039;s Blog","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.ch.ic.ac.uk\/rzepa\/blog\/?p=23319","og_locale":"en_GB","og_type":"article","og_title":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model. - Henry Rzepa&#039;s Blog","og_description":"Another foray into one of the more famous anecdotal chemistry &#8220;models&#8221;, the analysis of which led directly to the formulation of the WoodWard-Hoffmann (stereochemical) rules for pericyclic reactions. Previously, I tried to produce a modern computer model of what Woodward might have had to hand when discovering that the stereochemical outcome of a key reaction [&hellip;]","og_url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319","og_site_name":"Henry Rzepa&#039;s Blog","article_published_time":"2021-02-03T14:05:21+00:00","article_modified_time":"2021-02-05T18:28:33+00:00","og_image":[{"url":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg","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=23319#article","isPartOf":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319"},"author":{"name":"Henry Rzepa","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#\/schema\/person\/2b40f7b9c872a4dc1547e040a11b6281"},"headline":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model.","datePublished":"2021-02-03T14:05:21+00:00","dateModified":"2021-02-05T18:28:33+00:00","mainEntityOfPage":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319"},"wordCount":607,"commentCount":0,"image":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#primaryimage"},"thumbnailUrl":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg","articleSection":["Historical","pericyclic"],"inLanguage":"en-GB","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319","name":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model. - Henry Rzepa&#039;s Blog","isPartOf":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#primaryimage"},"image":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#primaryimage"},"thumbnailUrl":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg","datePublished":"2021-02-03T14:05:21+00:00","dateModified":"2021-02-05T18:28:33+00:00","author":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#\/schema\/person\/2b40f7b9c872a4dc1547e040a11b6281"},"breadcrumb":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#breadcrumb"},"inLanguage":"en-GB","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319"]}]},{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#primaryimage","url":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg","contentUrl":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2012\/12\/p2.svg"},{"@type":"BreadcrumbList","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23319#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog"},{"@type":"ListItem","position":2,"name":"The thermal reactions \u2026 took precisely the opposite stereochemical course to that which we had predicted. A non-covalent-interaction view of the model."}]},{"@type":"WebSite","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#website","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/","name":"Henry Rzepa&#039;s Blog","description":"Chemistry with a twist","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-GB"},{"@type":"Person","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#\/schema\/person\/2b40f7b9c872a4dc1547e040a11b6281","name":"Henry Rzepa","image":{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/secure.gravatar.com\/avatar\/897b6740f7f599bca7942cdf7d7914af5988937ae0e3869ab09aebb87f26a731?s=96&d=blank&r=g370be3a7397865e4fd161aefeb0a5a85","url":"https:\/\/secure.gravatar.com\/avatar\/897b6740f7f599bca7942cdf7d7914af5988937ae0e3869ab09aebb87f26a731?s=96&d=blank&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/897b6740f7f599bca7942cdf7d7914af5988937ae0e3869ab09aebb87f26a731?s=96&d=blank&r=g","caption":"Henry Rzepa"},"description":"Henry Rzepa is Emeritus Professor of Computational Chemistry at Imperial College London.","sameAs":["https:\/\/orcid.org\/0000-0002-8635-8390"],"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?author=1"}]}},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/pDef7-647","jetpack-related-posts":[{"id":23281,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23281","url_meta":{"origin":23319,"position":0},"title":"The Stevens rearrangement: how history gives us new insights.","author":"Henry Rzepa","date":"January 29, 2021","format":false,"excerpt":"In a recent post, I told the story of how in the early 1960s, Robert Woodward had encountered an unexpected stereochemical outcome to the reaction of a hexatriene, part of his grand synthesis of vitamin B12. He had constructed a model of the reaction he wanted to undertake, perhaps with\u2026","rel":"","context":"In &quot;Historical&quot;","block_context":{"text":"Historical","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=565"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2021\/01\/sden.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":23203,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=23203","url_meta":{"origin":23319,"position":1},"title":"The thermal reactions &#8230; took precisely the opposite stereochemical course to that which we had predicted","author":"Henry Rzepa","date":"January 20, 2021","format":false,"excerpt":"The quote of the post title comes from R. B. Woodward explaining the genesis of the discovery of what are now known as the Woodward-Hoffmann rules for pericyclic reactions. I first wrote about this in 2012, noting that \"for (that) blog, I do not want to investigate the transition states\".\u00a0Here\u2026","rel":"","context":"In &quot;crystal_structure_mining&quot;","block_context":{"text":"crystal_structure_mining","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=1745"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2021\/01\/Screenshot-515-300x215.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":12810,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=12810","url_meta":{"origin":23319,"position":2},"title":"Using a polar bond to flip: a follow up project.","author":"Henry Rzepa","date":"August 6, 2014","format":false,"excerpt":"In my earlier post on the topic, I discussed how inverting the polarity of the C-X bond from X=O to X=Be could flip the stereochemical course of the electrocyclic pericyclic reaction of a divinyl system. An obvious question would be: what happens at the half way stage, ie X=CH2? Well,\u2026","rel":"","context":"In &quot;pericyclic&quot;","block_context":{"text":"pericyclic","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=559"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":10145,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=10145","url_meta":{"origin":23319,"position":3},"title":"Feist&#8217;s acid. Stereochemistry galore.","author":"Henry Rzepa","date":"April 4, 2013","format":false,"excerpt":"Back in the days (1893) when few compounds were known, new ones could end up being named after the discoverer. Thus Feist is known for the compound bearing his name; the 2,3 carboxylic acid of methylenecyclopropane (1, with Me replaced by CO2H). Compound 1 itself nowadays is used to calibrate\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":"methylene-cyclopropane","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/04\/methylene-cyclopropane.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":12782,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=12782","url_meta":{"origin":23319,"position":4},"title":"Using a polar bond to flip the (stereochemical) outcome of a pericyclic reaction.","author":"Henry Rzepa","date":"August 4, 2014","format":false,"excerpt":"The outcome of pericyclic reactions con depend most simply on three conditions, any two of which determine the third. Whether the catalyst is \u0394 or h\u03bd (heat or light), the topology determining any stereochemistry and the participating electron count (4n+2\/4n). It is always neat to conjure up a simple switch\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":[]},{"id":5716,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=5716","url_meta":{"origin":23319,"position":5},"title":"A modern take on pericyclic sigmatropic migrations.","author":"Henry Rzepa","date":"November 29, 2011","format":false,"excerpt":"Another common type of pericyclic reaction is the migration of hydrogen or carbon along a conjugated chain, as in the [1,3] migration of a carbon as shown below. As before, I explore the stereochemistry of the thermal and photochemical reactions. The reaction is known to proceed thermally\u00a0with inversion of configuration\u2026","rel":"","context":"In \"pericyclic\"","block_context":{"text":"pericyclic","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?tag=pericyclic"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2011\/11\/s.gif?resize=350%2C200","width":350,"height":200},"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\/23319","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=23319"}],"version-history":[{"count":30,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/23319\/revisions"}],"predecessor-version":[{"id":23357,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/23319\/revisions\/23357"}],"wp:attachment":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23319"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23319"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23319"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fppma_author&post=23319"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}