Review article

Topological Ring-Currents in Condensed Benzenoid Hydrocarbons

R. B. Mallion ; School of Physical Sciences, University of Kent, Canterbury, England, United Kingdom

Abstract

Topological ring-currents are defined as being pi-electron ring-current intensities in condensed,
benzenoid hydrocarbons that (i) are calculated by the simplest Hückel-London-Pople-
McWeeny method, (ii) are based on a molecular geometry of regular hexagons of carbon atoms,
and (iii) are expressed as a ratio to the corresponding ring-current intensity calculated, by
the same method, for benzene. Once a particular benzenoid hydrocarbon has been specified,
such topological ring-currents are predetermined and do not further depend on any subjective
(or other) parameters; they are, therefore, purely graph-theoretical indices, reliant solely on
knowledge of a vertex-adjacency matrix for the graph representing the connectivity of the carbon
atoms in the benzenoid molecule under study. For convenient reference, tables of all
known topological ring-current intensities – some published, and others so-far unpublished –
are presented for future evaluation and possible comparison with other graph-theoretical indices
that characterise the individual rings of a condensed, benzenoid hydrocarbon.

Keywords

ring currents; benzenoid hydrocarbons; graph theory

Hrčak ID:

28146

URI

https://hrcak.srce.hr/28146

Publication date:

30.6.2008.

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