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. © 1992 John Wiley & Sons, Inc.