{"id":9322,"date":"2013-02-01T20:37:31","date_gmt":"2013-02-01T20:37:31","guid":{"rendered":"http:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=9322"},"modified":"2013-02-01T20:37:31","modified_gmt":"2013-02-01T20:37:31","slug":"anapolar-ring-currents-a-144-annulene","status":"publish","type":"post","link":"https:\/\/www.rzepa.net\/blog\/?p=9322","title":{"rendered":"Anapolar ring currents: a [144]-Annulene."},"content":{"rendered":"
\n

This is a recently published[1]<\/a><\/span> (hypothetical) molecule which has such unusual properties that I cannot resist sharing it with you. It is an annulene with 144 all-cis CH groups, being a (very) much larger cousin of (also hypothetical) systems mooted in 2009[2]<\/a><\/span>,[3]<\/a><\/span>.<\/p>\n

\"A

A 144-carbon annulene. Click for 3D.<\/p><\/div>\n

One fascinating novel aspect of Berger’s work is that he identifies that such helical systems will exhibit a distinct anapolar ring current structure in a constant and homogeneous magnetic field, perpendicular to the main molecular plane<\/em>. Such anapolar magnetism is distinctly different from the dipolar (diatropic) ring currents normally associated with aromatic molecules, and with the current interest in the magnetic properties of graphene-like objects (see also this blog post<\/a>\u00a0 and also the helical metal wire<\/a>) such molecules can only help to excite our imaginations.\u00a0<\/p>\n

I also show one of the more stable molecular orbitals for the [144]-annulene (\u03c9B97XD\/6-31G(d,p) calculation<\/a>).\u2021<\/sup> Molecular art indeed!<\/p>\n

\"MO

MO 461. Click for 3D.<\/p><\/div>\n

If you go to the Knotplot site<\/a>, there you will find a torus link of form (2,18), which displays as the below. Look familiar? Notice the chirality is opposite however!<\/p>\n

\"link-2-18\"<\/a><\/p>\n

\n

\u2021<\/sup>Orbitals for smaller rings with such form can be found here<\/a>.<\/p>\n

References<\/h2>\n
  1. R.J.F. Berger, \"Prediction of a Cyclic Helical Oligoacetylene Showing Anapolar Ring Currents in the Magnetic Field\", Zeitschrift f\u00fcr Naturforschung B<\/i>, vol. 67, pp. 1127-1131, 2012. https:\/\/doi.org\/10.5560\/znb.2012-0189<\/a>\n\n<\/li>\n
  2. S.M. Rappaport, and H.S. Rzepa, \"Intrinsically Chiral Aromaticity. Rules Incorporating Linking Number, Twist, and Writhe for Higher-Twist M\u00f6bius Annulenes\", Journal of the American Chemical Society<\/i>, vol. 130, pp. 7613-7619, 2008. https:\/\/doi.org\/10.1021\/ja710438j<\/a>\n\n<\/li>\n
  3. C.S. Wannere, H.S. Rzepa, B.C. Rinderspacher, A. Paul, C.S.M. Allan, H.F. Schaefer, and P.V.R. Schleyer, \"The Geometry and Electronic Topology of Higher-Order Charged M\u00f6bius Annulenes\", The Journal of Physical Chemistry A<\/i>, vol. 113, pp. 11619-11629, 2009. https:\/\/doi.org\/10.1021\/jp902176a<\/a>\n\n<\/li>\n<\/ol>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

    This is a recently published (hypothetical) molecule which has such unusual properties that I cannot resist sharing it with you. It is an annulene with 144 all-cis CH groups, being a (very) much larger cousin of (also hypothetical) systems mooted in 2009,. One fascinating novel aspect of Berger’s work is that he identifies that such […]<\/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":[963,964],"class_list":["post-9322","post","type-post","status-publish","format-standard","hentry","category-interesting-chemistry","tag-helical-metal-wire","tag-helical-systems"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1gPyz-2qm","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/9322","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=9322"}],"version-history":[{"count":0,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/9322\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9322"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9322"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}