A Direct Route to a Polybromothiophene as a Precursor for Functionalized Polythiophene by Electrooxidative Polymerization

Abstract

A reactive π-conjugated polymer, bromo-substituted polythiophene, was synthesized by constant potential electrooxidative polymerization of 3-bromo-4-dodecylthiophene in an acetonitrile solution of Bu₄NPF₆. The resulting polymer was applied as a reactive precursor for functional polythiophenes. The protonation via lithiation of the polybromothiophene proceeded quantitatively. The phenylation of the polybromothiophene by the Kumada-Tamao coupling reaction also proceeded with a 70 % efficiency. The changes in optical and electronic properties of the polymers by their reactions are discussed by the results of UV-vis absorption spectroscopy, photoluminescence spectroscopy, and cyclic voltammetric analysis. The emission colors of the bromo-substituted, protonated, and phenylated polymers were green, yellow, and blue, respectively, demonstrating the tunability of this approach.