Synthesis and characterization of polythiophenes with alkenyl substituents

Abstract

Synthesis of polythiophenes with alkenyl side chains is reported for the first time. The alkenyl side chains are versatile functional groups, allowing facile chemical modification to generate novel materials with tunable opto-electronic properties. Poly(3-pentenylthiophene), poly(3-undecenylthiophene), poly(3-hexylthiophene-ran-3-pentenylthiophene) and poly(3-hexylthiophene-ran-3-undecenylthiophene) were synthesized by a nickel mediated cross-coupling polymerization. Poly(3-alkenylthiophene) homopolymers and random copolymers were prepared from 2-bromo-5-chlorozinc-3-alkenylthiophene monomers using Ni(dppp)Cl₂ as catalyst. The field-effect mobilities and photovoltaic response in bulk heterojunction solar cells were measured for poly(3-hexylthiophene-ran-3-pentenylthiophene) and poly(3-hexylthiophene-ran-3-undecenylthiophene).