Electrochemical synthesis and spectroscopic study of poly(3-alkylthienylenes)

Abstract The class of poly(3-alkylthienylenes) [P3ATs] has been synthesized by an improved method of electrochemical polymerization carried out under a rigorously oxygen-free and moisture-free environment. Within this class, the highest conductivity (750 S/cm) was obtained for poly(3-methylthienylene). The P3ATs (carrying hydrocarbon chains with carbon numbers of four or more) also show relatively high conductivities ranging from about 1 to 10 2 S/cm. The P3ATs with relatively longer hydrocarbon chains show good solubility in various organic solvents and can be readily processed from solution both in the neutral and in the conducting (oxidized) form. Copolymers based on the soluble P3ATs (obtained from random copolymerization of two kinds of thiophene monomers) are characterized by their high conductivity and excellent solubility. The influence of the hydrocarbon side chains on the electronic structure of the π-conjugated system of P3ATs is discussed.