Poly (alkyl thiophenes) and Poly (substituted heteroaromatic vinylenes): Versatile, Highly Conductive, Processible Polymers with Tunable Properties

Abstract

Conductive polymers derived from heteroaromatics such as thiophenes, furans, and pyrroles have been found to be a highly versatile conductive polymers. Unlike other conducting polymers, such as polyacetylene and polyphenylene, the polyheteroaromatics can be substituted with a variety of substituents to give polymers with widely varied physical and optical properties while maintaining high levels of conductivity. Especially versatile are polymers based on thiophenes. Here, long-chain alkyl substituents render the rigid polythiophenes solution processible in both the neutral and conductive forms. Further, strong electron donating or electron withdrawing groups can dramatically influence both polymer ionization potential and band gap. Such ready substitution allows one to fine tune the oxidative and reductive potentials of the polymer as well as manipulate the optical properties of the neutral and conductive forms. Adding a vinyl linkage between heteroaromatic rings reduces both the band gap and ionization potential of the parent polymer while providing a simplified route to their preparation and fabrication via the sulphonium polyelectrolyte precursor route. Herein we describe the preparation and properties of these novel materials.