Bond Distortions in Dibenzo[a,g]-s-indacene and Its Congeners

Abstract

Semiempirical MO calculations predict that dicyclopenta[a,g]-, dicyclopenta[a,h]-, dibenzo[a,g]-, dicyclohepta[a,g]-, and dicyclohepta[a,h]-s-indacene undergo no bond distortions, retaining the full molecular symmetry groups, whereas dibenzo[a,h]-s-indacene suffers a pseudo Jahn–Teller bond distortion from C_2v to C_s.