Conformational disorder in conjugated polymers

Abstract

Conformational disorder plays an important role in determining the electronic properties of conjugated polymers. To obtain a better theoretical description of the role and extent of conformational disorder, we derive the π electron correlation length and the bond correlation length in terms of the effective torsional potential and geometry of the conjugated polymer chains. These quantites are related to the conjugation lengths and persistence lengths of the chain, which are computed for polyacetylene, polydiacetylene, polythiophene, and polypyrrole. In spite of uncertainties in the torsional potential parameters for these materials, good qualitative agreement is found between experiment and theory.