Double aromaticity and ring currents in all-carbon rings

Chemistry. 2009 Jul 13;15(28):6964-72. doi: 10.1002/chem.200900322.

Abstract

Double aromaticity of neutral, planar rings of carbon atoms is demonstrated through visualisation of the induced ring currents, mapped at the ipsocentric B3LYP/6-31G(d)//B3LYP/6-31G(d) level for species C(6) to C(30), with onset of delocalised current in the in-plane pi system at C(10)/C(11). Both in-plane and conventional out-of-plane pi systems have diatropic/paratropic current in accordance with the Hückel rule, with 4 m+2 occupation of the out-of-plane pi system taking precedence, as predicted by simple nesting of Frost-Musulin diagrams. The current-density maps show characteristic double-doughnut and double-track topographies for out-of-plane and in-plane ring currents, respectively, both governed by a common framework of angular momentum rules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • Electrons
  • Hydrocarbons, Aromatic / chemistry*
  • Magnetics
  • Physical Phenomena

Substances

  • Hydrocarbons, Aromatic
  • Carbon