{"id":19807,"date":"2018-07-25T09:16:24","date_gmt":"2018-07-25T08:16:24","guid":{"rendered":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=19807"},"modified":"2018-08-13T14:11:19","modified_gmt":"2018-08-13T13:11:19","slug":"a-theoretical-method-for-distinguishing-x%e2%80%90h-bond-activation-mechanisms","status":"publish","type":"post","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807","title":{"rendered":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms."},"content":{"rendered":"
\n

Consider the four reactions. The first two are taught in introductory organic chemistry as (a) a proton transfer,\u00a0<\/span>often abbreviated PT,<\/span>\u00a0from X to B (a base) and (b) a hydride transfer<\/span> from X to A (an acid). The third example is taught as a hydrogen atom transfer or HAT<\/span> from X to (in this example) O. Recently an article has appeared[1]<\/a><\/span> citing an example of a fourth fundamental type (d), which is given the acronym cPCET which I will expand later.<\/span><\/span>\u00a0Here I explore this last type a bit further, in the context that X-H bond activations are currently a very active area of research.
\n\"\"<\/a><\/p>\n

To help understand these four types, I have colour-coded the electron pair constituting the X-H covalent bond in red<\/span>.<\/p>\n

    \n
  1. In mechanism (a), this electron pair stays with X, thus liberating a proton which is captured by the base.<\/li>\n
  2. The hydride transfer (b) is so-called because in fact this electron pair travels together with the proton, hence the term hydride or H–<\/sup><\/span><\/strong>.<\/li>\n
  3. Hydrogen atom transfers as in (c) in effect transfer both a proton and one electron to another atom (oxygen in the example above), leaving behind one electron on X. The electron and the proton are said to travel together as a “true” hydrogen atom.<\/li>\n
  4. The fourth mechanism (d) is fundamentally different from (c) in that whilst the electron and the proton travel in concert (at the same time), they do not travel together. In this example the proton travels to the oxygen, whilst the electron travels to the iron centre, in the process reducing its oxidation state. This mode is now called a concerted proton-coupled electron transfer<\/em>, or cPCET<\/span><\/strong> as above.<\/li>\n<\/ol>\n

    The tool employed to distinguish between mechanisms (c) and (d) is the IBO or intrinsic bond orbital localisation scheme.[2]<\/a><\/span> One practical advantage of such a scheme over better known localisation methods such as NBO (Natural bond orbitals) is that IBOs can be made to transform smoothly during the course of a reaction, as followed by say an IRC (Intrinsic reaction coordinate). NBOs may instead show discontinuous behaviour along a reaction IRC. Klein and Knizia have located transition states for examples of both (c) and (d) above and studied the IBOs along such IRCs. The two IBO reaction transformations are very different, as illustrated below (used, with permission, from the article itself). For the HAT type (X=C above), an \u03b1-spin IBO morphs from a C-H bond into a H-O bond, whilst the \u03b2-spin counterpart morphs from being located on the C-H bond into a carbon-centered radical. For the cPCET mode, the \u03b1-spin IBO morphs from C-H to a C-centered radical, but the \u03b2-spin region grows onto an iron d-orbital. It is in fact even more complex than the diagram above implies, since some reorganisation of the O-Fe region occurs and the H…:O region is still anti-bonding at the transition state.<\/p>\n

    \"\"<\/p>\n

    We can see from this that mechanistic reaction analysis is starting to track the “curly arrows” we conventionally use to represent reactions in some detail, as well as informing us about the relative detailing timing of the various curly arrows used. Of course this latter aspect cannot be easily represented by conventional curly arrows. It seems timely to revisit the vast corpus of organic and organometallic “curly arrow pushing” to starting adding such information!<\/p>\n

    References<\/h2>\n
    1. J.E.M.N. Klein, and G. Knizia, \"cPCET versus HAT: A Direct Theoretical Method for Distinguishing X\u2013H Bond\u2010Activation Mechanisms\", Angewandte Chemie International Edition<\/i>, vol. 57, pp. 11913-11917, 2018. https:\/\/doi.org\/10.1002\/anie.201805511<\/a>\n\n<\/li>\n
    2. G. Knizia, \"Intrinsic Atomic Orbitals: An Unbiased Bridge between Quantum Theory and Chemical Concepts\", Journal of Chemical Theory and Computation<\/i>, vol. 9, pp. 4834-4843, 2013. https:\/\/doi.org\/10.1021\/ct400687b<\/a>\n\n<\/li>\n<\/ol>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

      Consider the four reactions. The first two are taught in introductory organic chemistry as (a) a proton transfer,\u00a0often abbreviated PT,\u00a0from X to B (a base) and (b) a hydride transfer from X to A (an acid). The third example is taught as a hydrogen atom transfer or HAT from X to (in this example) O. […]<\/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":[4],"tags":[1609,1395,2425,1450,1960,2423,1528,2426,2424,1405],"ppma_author":[2661],"class_list":["post-19807","post","type-post","status-publish","format-standard","hentry","category-interesting-chemistry","tag-chemical-reactions","tag-chemistry","tag-deprotonation","tag-hydride","tag-hydrogen","tag-hydrogen-atom-abstraction","tag-proton","tag-proton-travel","tag-proton-coupled-electron-transfer","tag-technologyinternet"],"yoast_head":"\nA Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms. - Henry Rzepa'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=19807\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms. - Henry Rzepa's Blog\" \/>\n<meta property=\"og:description\" content=\"Consider the four reactions. The first two are taught in introductory organic chemistry as (a) a proton transfer,\u00a0often abbreviated PT,\u00a0from X to B (a base) and (b) a hydride transfer from X to A (an acid). The third example is taught as a hydrogen atom transfer or HAT from X to (in this example) O. […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807\" \/>\n<meta property=\"og:site_name\" content=\"Henry Rzepa's Blog\" \/>\n<meta property=\"article:published_time\" content=\"2018-07-25T08:16:24+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2018-08-13T13:11:19+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.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":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms. - Henry Rzepa'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=19807","og_locale":"en_GB","og_type":"article","og_title":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms. - Henry Rzepa's Blog","og_description":"Consider the four reactions. The first two are taught in introductory organic chemistry as (a) a proton transfer,\u00a0often abbreviated PT,\u00a0from X to B (a base) and (b) a hydride transfer from X to A (an acid). The third example is taught as a hydrogen atom transfer or HAT from X to (in this example) O. […]","og_url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807","og_site_name":"Henry Rzepa's Blog","article_published_time":"2018-07-25T08:16:24+00:00","article_modified_time":"2018-08-13T13:11:19+00:00","og_image":[{"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.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=19807#article","isPartOf":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807"},"author":{"name":"Henry Rzepa","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#\/schema\/person\/2b40f7b9c872a4dc1547e040a11b6281"},"headline":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms.","datePublished":"2018-07-25T08:16:24+00:00","dateModified":"2018-08-13T13:11:19+00:00","mainEntityOfPage":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807"},"wordCount":571,"commentCount":0,"image":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#primaryimage"},"thumbnailUrl":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.svg","keywords":["chemical reactions","Chemistry","Deprotonation","Hydride","Hydrogen","Hydrogen atom abstraction","Proton","proton travel","Proton-coupled electron transfer","Technology\/Internet"],"articleSection":["Interesting chemistry"],"inLanguage":"en-GB","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807","name":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms. - Henry Rzepa's Blog","isPartOf":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#primaryimage"},"image":{"@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#primaryimage"},"thumbnailUrl":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.svg","datePublished":"2018-07-25T08:16:24+00:00","dateModified":"2018-08-13T13:11:19+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=19807#breadcrumb"},"inLanguage":"en-GB","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807"]}]},{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#primaryimage","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.svg","contentUrl":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2018\/07\/XH-page001.svg"},{"@type":"BreadcrumbList","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=19807#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog"},{"@type":"ListItem","position":2,"name":"A Theoretical Method for Distinguishing X\u2010H Bond Activation Mechanisms."}]},{"@type":"WebSite","@id":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/#website","url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/","name":"Henry Rzepa'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\/pDef7-59t","jetpack-related-posts":[{"id":10839,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=10839","url_meta":{"origin":19807,"position":0},"title":"Hexacoordinate hydrogen.","author":"Henry Rzepa","date":"July 8, 2013","format":false,"excerpt":"A feature of a blog which is quite different from a journal article is how rapidly a topic might evolve.\u00a0Thus I started a few days ago with the theme of dicarbon (C2), identifying a metal carbide that showed C2 as a ligand, but which also entrapped a single carbon in\u2026","rel":"","context":"In "Hypervalency"","block_context":{"text":"Hypervalency","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=7"},"img":{"alt_text":"Click for 3D.","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/07\/6-H.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":11642,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=11642","url_meta":{"origin":19807,"position":1},"title":"Avoided (pericyclic) anti-aromaticity: Reactions of t-butyl-hydroxycarbene.","author":"Henry Rzepa","date":"November 13, 2013","format":false,"excerpt":"Not long ago, I described a cyclic carbene in which elevating the carbene lone pair into a \u03c0-system transformed it from a formally 4n-antiaromatic \u03c0-cycle into a 4n+2 aromatic \u03c0-cycle. From an entirely different area of chemistry, another example of this behaviour emerges; Schreiner's trapping and reactions of t-butyl-hydroxycarbene, as\u2026","rel":"","context":"In "pericyclic"","block_context":{"text":"pericyclic","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=559"},"img":{"alt_text":"H-mig","src":"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/11\/H-mig.gif?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":16118,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=16118","url_meta":{"origin":19807,"position":2},"title":"Hydronium hydroxide: the why of pH 7.","author":"Henry Rzepa","date":"April 14, 2016","format":false,"excerpt":"Ammonium hydroxide (NH4+...OH-) can be characterised quantum mechanically when stabilised by water bridges connecting the ion-pairs. It is a small step from there to hydronium hydroxide, or H3O+...OH-. The measured concentrations [H3O+] \u2261 [OH-]\u00a0give\u00a0rise of course to the well-known\u00a0pH 7 of pure water, and converting this ionization constant to a\u2026","rel":"","context":"In "General"","block_context":{"text":"General","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=1"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":22445,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=22445","url_meta":{"origin":19807,"position":3},"title":"Curly arrows in the 21st Century. Proton-coupled electron transfers.","author":"Henry Rzepa","date":"June 10, 2020","format":false,"excerpt":"One of the most fascinating and important articles dealing with curly arrows I have seen is that by Klein and Knizia on the topic of C-H bond activations using an iron catalyst. These are so-called high spin systems with unpaired electrons and the mechanism of C-H activation involves both double\u2026","rel":"","context":"In "Curly arrows"","block_context":{"text":"Curly arrows","link":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?cat=2327"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.ch.ic.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2020\/06\/TS.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":20354,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=20354","url_meta":{"origin":19807,"position":4},"title":"Epoxidation of ethene: a new substituent twist.","author":"Henry Rzepa","date":"December 21, 2018","format":false,"excerpt":"Five years back,\u00a0I speculated about the mechanism of the epoxidation of ethene by a peracid, concluding that kinetic isotope effects provided interesting evidence that this mechanism is highly asynchronous and involves a so-called \"hidden intermediate\". Here I revisit this reaction in which a small change is applied to the atoms\u2026","rel":"","context":"In "Interesting chemistry"","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\/2018\/12\/imine2.gif?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":20576,"url":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/?p=20576","url_meta":{"origin":19807,"position":5},"title":"The shortest known CF…HO hydrogen bond.","author":"Henry Rzepa","date":"March 24, 2019","format":false,"excerpt":"There is a predilection amongst chemists for collecting records; one common theme is the length of particular bonds, either the shortest or the longest. A particularly baffling type of bond is that between the very electronegative F atom and an acid hydrogen atom such as that in OH. Thus short\u2026","rel":"","context":"In "crystal_structure_mining"","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\/2019\/03\/F-inter-300x189.png?resize=350%2C200&ssl=1","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\/19807","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=19807"}],"version-history":[{"count":17,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/19807\/revisions"}],"predecessor-version":[{"id":19827,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=\/wp\/v2\/posts\/19807\/revisions\/19827"}],"wp:attachment":[{"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19807"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19807"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19807"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.ch.ic.ac.uk\/rzepa\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fppma_author&post=19807"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}