Defect states in poly(p-phenylene methine) and similar materials

Abstract

The electronic structure of poly(p-phenylene methine), PPM, obtained using a Hückel model with a bond-order bond-length relationship is degenerate and capable of supporting soliton defects, PPM thus being the parent of a class of π-conjugated polymer characterised by a repeat unit consisting of a ring sequence symmetrically interconnected by an odd-alternant group; an unusual structural relaxation about the polaron defect for PPM is described.