A Concept to Relate the ZFS Parameter D of Aromatic Hydrocarbons to Molecular and Electronic Structure

Abstract

Abstract New aspects for the interpretation of the zero field splitting parameter D of the lowest excitet triplet state of polycyclic hydrocarbons are presented. A model connecting the dipole-dipole interaction between the two triplet electrons with Clar’s concept of electronic sextets is employed. It follows that even in highly condensed aromatic molecules the probability for the two triplet electrons to be localized on one C6-ring unit can be relative high. This concept is outlined taking the experimental D-values of a series of pyrene derivatives as an example