Synthesis and Electrochemical Polymerization of Dithienosilole-Based Monomers Bearing Different Donor Units

Abstract

Three new donor-acceptor-donor (DAD) type monomers containing five membered heteroaromatic rings as the donor units and the silicon-bridged bithiophene as the acceptor unit were synthesized via Stille cross-coupling reaction. The monomers,2,6-di(furan-2-yl)-4,4-dioctyl-4H-silolo[3,2-b:4,5-b′]dithiophene (FSiF), 4,4-dioctyl-2,6-di(thiophen-2-yl)-4H-silolo[3,2-b:4,5-b′]dithiophene (TSiT) and 4,4-dioctyl-2,6-di(selenophen-2-yl)-4H-silolo[3,2-b:4,5-b′]dithiophene (SeSiSe) were polymerized electrochemically via potential cycling in acetonitrile–tetrabutylammonium perchlorate electrolytic medium. Optical and electrochemical properties of the monomers and their corresponding polymers were investigated and it was found that oxidation potentials of the monomers and optical properties of both monomers and their polymers showed slight variations depending on the heteroatom present in the donor unit.