Synthesis and characterization of new sulfone‐derivatized phenylenevinylene‐based conjugated copolymers with evolving energy levels and gaps

Abstract

A new series of stable, processable, and chain end functionalizable sulfone-derivatized phenylenevinylene-based conjugated polymers (SFPVs) containing different donor type comonomers have been synthesized and characterized. The polymer main chains are consisted of a sulfone-phenylene electron accepting unit coupled with an electron donating unit which is derived from one of the dialdehyde comonomers based on benzene, thiophene, and pyrrole (with or without alkoxy side chains). The optical energy gaps (Eg) of the new polymers (in solvent) are in a range of 1.9–2.3 eV, with the lowest energy gap obtained from the polymer containing pyrrole as the donor unit. By using a combination of strong donor unit (such as pyrrole) and a relatively weak but stable acceptor unit (sulfone-substituted benzene), Eg of the conjugated polymers can be tailored to below 2 eV, while the vinylene bonds on the polymer main chain are still chemically stable to survive strong basic conditions as compared with the S,S-dioxo-thiophene-based PTV polymers developed earlier for potential supra-molecular block copolymer systems. The lowest energy gap P(Pyrrole-SFPV) exhibited 10 times better photoelectric power conversion efficiency than P(TV-SFPV). VC 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 1197– 1204, 2012