{"id":19550,"date":"2018-04-13T11:05:29","date_gmt":"2018-04-13T10:05:29","guid":{"rendered":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=19550"},"modified":"2018-04-13T11:05:29","modified_gmt":"2018-04-13T10:05:29","slug":"a-record-polarity-for-a-neutral-compound","status":"publish","type":"post","link":"https:\/\/www.rzepa.net\/blog\/?p=19550","title":{"rendered":"A record polarity for a neutral compound?"},"content":{"rendered":"
\n

In several posts<\/a> a year or so ago I considered various suggestions for the most polar neutral molecules, as measured by the dipole moment. A record had been claimed[1]<\/a><\/span> for a synthesized molecule of ~14.1\u00b10.7D. I pushed this to a calculated 21.7D for an admittedly hypothetical and unsynthesized molecule. Here I propose a new family of compounds which have the potential to extend the dipole moment for a formally neutral molecule up still further.<\/p>\n

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

These molecules derive from a well-known class of molecule known as ortho-quinomethides. If the methide part is substituted with an electron donating substituent such as an amino group in 3<\/strong>, a push-pull opportunity now arises, which is strongly driven by aromatisation of the quinomethide ring. This allows one to design “neutral” molecules such as 1<\/strong> and 2<\/strong>, which now contain respectively two and three rings that will be aromatised by the process. The aromatisation stabilization energy is balanced of course by an opposing increase in energy resulting from charge separation.\u00a0You can observe that partially aromatising three independent rings as in 2<\/strong> can drive a great deal of charge separation. One may indeed wonder how much charge separation can be sustained before a triplet instability occurs, driving the molecule back to being neutral. In the case of 2<\/strong>, the wavefunction is in fact stable to such an open shell state, but higher homologues may not be. An aspect worth investing!<\/p>\n\n\n\n\n\n\n
1<\/th>\n2<\/th>\n<\/tr>\n
\"\"<\/td>\n\"\"<\/td>\n<\/tr>\n
DM 12.3<\/td>\nDM 31.5<\/td>\n<\/tr>\n
DOI: 10.14469\/hpc\/4004<\/a><\/td>\nDOI: 10.14469\/hpc\/4059<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Molecule 1<\/b>\u00a0does have some precedent in 3<\/strong>[2]<\/a><\/span> but this system exists as a phenol, having abstracted a proton from an acid and leaving behind the acid anion, as per below for 1<\/strong>. Any attempts to deprotonate this phenol with a superstrong base were unreported.<\/p>\n

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

Unsurprisingly therefore, molecules such as 1<\/strong> and 2<\/strong>\u00a0could be regarded as even more highly potent bases than 3<\/strong>, driven again by further aromatisation. The properties of such a potential superbase will be investigated in the next post.<\/p>\n

References<\/h2>\n
  1. J. Wudarczyk, G. Papamokos, V. Margaritis, D. Schollmeyer, F. Hinkel, M. Baumgarten, G. Floudas, and K. M\u00fcllen, \"Hexasubstituted Benzenes with Ultrastrong Dipole Moments\", Angewandte Chemie International Edition<\/i>, vol. 55, pp. 3220-3223, 2016. https:\/\/doi.org\/10.1002\/anie.201508249<\/a>\n\n<\/li>\n
  2. N.R. Candeias, L.F. Veiros, C.A.M. Afonso, and P.M.P. Gois, \"Water: A Suitable Medium for the Petasis Borono\u2010Mannich Reaction\", European Journal of Organic Chemistry<\/i>, vol. 2009, pp. 1859-1863, 2009. https:\/\/doi.org\/10.1002\/ejoc.200900056<\/a>\n\n<\/li>\n<\/ol>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

    In several posts a year or so ago I considered various suggestions for the most polar neutral molecules, as measured by the dipole moment. A record had been claimed for a synthesized molecule of ~14.1\u00b10.7D. I pushed this to a calculated 21.7D for an admittedly hypothetical and unsynthesized molecule. Here I propose a new family […]<\/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":[6],"tags":[2427,1968,512,1416,1432,1971,1654,147,1988,1881,1990,1894,1668],"class_list":["post-19550","post","type-post","status-publish","format-standard","hentry","category-interesting-chemistry","tag-aromatisation-stabilization-energy","tag-chemical-polarity","tag-chemical-properties","tag-chemistry","tag-dipole","tag-electric-dipole-moment","tag-electromagnetism","tag-energy","tag-moment","tag-nature","tag-physical-quantities","tag-physics","tag-potential-theory"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1gPyz-55k","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/19550","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=19550"}],"version-history":[{"count":0,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/19550\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19550"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19550"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}