POLY(3,3'-DIMETHOXY-2,2'-BITHIOPHENE) - SYNTHESIS AND COMPARISON WITH POLY(3-METHOXYTHIOPHENE)

A new electroactive polymer, namely poly (3,3'-dimethoxy-2,2'-bithiophene) has been prepared by voltammetric polymerization of 3,3'-dimethoxy-2,2'-bithiophene. Due to a different coupling pattern (equivalent to "head-to-head," and "tail-to-tail" coupled alkoxythiophene rings), poly(3,3'-dimethoxy-2,2'-bithiophene) exhibits different voltammetric properties than the corresponding "head-to-tail" coupled polymer, i.e., poly(3-methoxythiophene). Poly(3,3'-dimethoxy-2,2'-bithiophene) gives very sharp oxidation and reduction peaks indicating an abrupt insulator to conductor transition. This hypothesis was corroborated by the studies of relative resistance as a function of electrode potential. Sharper and better-defined redox peaks may indicate better stereoregularity of poly(3,3'-dimethoxy-2,2'-bithiophene) as compared to poly(3-methoxythiophene) since in this compound the 5,5'-coupling positions are geometrically equivalent and no coupling defects are expected.