{"id":22391,"date":"2020-05-25T12:35:33","date_gmt":"2020-05-25T11:35:33","guid":{"rendered":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=22391"},"modified":"2020-05-25T12:35:33","modified_gmt":"2020-05-25T11:35:33","slug":"the-strongest-bond-in-the-universe-a-crystallographic-reality-check","status":"publish","type":"post","link":"https:\/\/www.rzepa.net\/blog\/?p=22391","title":{"rendered":"The strongest bond in the universe: A crystallographic reality check?"},"content":{"rendered":"
\n

My previous<\/a> two posts on the topic of strongest bonds have involved mono and diprotonating N2<\/sub> and using quantum mechanics to predict the effect this has on the N-N bond via<\/em> its length and vibrational stetching mode. Such species are very unlikely to be easily observed for verification. But how about a metal M+<\/sup> instead of H+<\/sup>? It turns out that structures containing the fragment Ru-N\u2261N-Ru are a small but well studied class of organometallic. Here is a search of the CSD crystal database for this motif.<\/p>\n

\"\"<\/a><\/p>\n

The three examples showing the shortest N-N distances are shown below.[1]<\/a><\/span>,[2]<\/a><\/span>[3]<\/a><\/span><\/p>\n

\"\"<\/a> \"\"<\/a> \"\"<\/a><\/p>\n

The NN distances for these three examples are in the region of 1.1\u00c5. There are 39 structures in total, for a variety of other transition metals, with a length <1.15\u00c5. The angles subtended at N are close to linear;<\/p>\n

\"\"<\/a><\/p>\n

 <\/p>\n

For comparison, N2<\/sub> itself entrained into a crystal structure has the value of ~1.096<\/a>\u00c5 as measured at 80K (R-factor 0.84%)[4]<\/a><\/span>) which is pretty similar to the value computed in the previous post (1.103\u00c5). \u00a0<\/p>\n

So the question to ask is whether any of these organometallic examples have an NN bond at least as strong as that in dinitrogen itself? Only a reliable value for the force constant will give us a clear picture, which however would be non-trivial for such species. But it does suggest that asking whether there could be a real candidate for the strongest bond in the universe other than N2<\/sub> itself may not be entirely futile.<\/p>\n

 <\/p>\n

References<\/h2>\n
  1. Y. Sun, H. Chan, and Z. Xie, \"Reaction Scope and Mechanism of Sterically Induced Ruthenium-Mediated Intramolecular Coupling of<i>o<\/i>-Carboranyl with Cyclopentadienyl. Synthesis and Structure of Ruthenium Complexes Incorporating Doubly Linked Cyclopentadienyl\u2212Carboranyl Ligands\", Organometallics<\/i>, vol. 25, pp. 4188-4195, 2006. https:\/\/doi.org\/10.1021\/om0604122<\/a>\n\n<\/li>\n
  2. Y. Tanabe, S. Kuriyama, K. Arashiba, K. Nakajima, and Y. Nishibayashi, \"Synthesis and Reactivity of Ruthenium Complexes Bearing Arsenic-Containing Arsenic-Nitrogen-Arsenic-Type Pincer Ligand\", Organometallics<\/i>, vol. 33, pp. 5295-5300, 2014. https:\/\/doi.org\/10.1021\/om5006116<\/a>\n\n<\/li>\n
  3. K. Abdur-Rashid, D.G. Gusev, A.J. Lough, and R.H. Morris, \"Synthesis and Characterization of RuH<sub>2<\/sub>(H<sub>2<\/sub>)<sub>2<\/sub>(P<sup>i<\/sup>Pr<sub>3<\/sub>)<sub>2<\/sub> and Related Chemistry. Evidence for a Bis(dihydrogen) Structure\", Organometallics<\/i>, vol. 19, pp. 1652-1660, 2000. https:\/\/doi.org\/10.1021\/om990669i<\/a>\n\n<\/li>\n
  4. C. Dou, W. Kosaka, and H. Miyasaka, \"Gate-open-type Sorption in a Zigzag Paddlewheel Ru Dimer Chain Compound with a Phenylenediamine Linker Instructed by a Preliminary Structural Change of Desolvation\", Chemistry Letters<\/i>, vol. 46, pp. 1288-1291, 2017. https:\/\/doi.org\/10.1246\/cl.170509<\/a>\n\n<\/li>\n<\/ol>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

    My previous two posts on the topic of strongest bonds have involved mono and diprotonating N2 and using quantum mechanics to predict the effect this has on the N-N bond via its length and vibrational stetching mode. Such species are very unlikely to be easily observed for verification. But how about a metal M+ instead […]<\/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,"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":[1754],"tags":[],"class_list":["post-22391","post","type-post","status-publish","format-standard","hentry","category-crystal_structure_mining"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1gPyz-5P9","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/22391","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=22391"}],"version-history":[{"count":0,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/22391\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=22391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=22391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=22391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}