Pairwise energy effect of cyclic conjugation in benzo-annelated perylenes

Abstract

Previous analysis of cyclic conjugation in benzo-annelated perylenes has revealed that annelation of a benzene ring in the angular position increases the extent of cyclic conjugation in the central ring whereas annelation of a benzene ring in the linear position reduces it. We now present a general method for assessing the effect of a ring on the energy effect of cyclic conjugation in another ring. The respective quantity, referred to as the pairwise energy effect, is used to rationalize specific modes of cyclic conjugation in benzo-annelated perylenes.