Reductive Polymerization of Halothiophene

Abstract

ABSTRACT:The reductive preparation of poly(thiophene) and copolymers from 2,5-dibromothiophene and tetrabromothiophene is described. In this reaction, hydrazine and palladium catalysts were used. Yield of the polymer was 65% when 2,5-dibromothiophene was used as a monomer. Electric conductivity of the polymer was 1 x 10-5 S cm -1 (1 2 20 wt¾) and 1 x 10-3 S cm -1 (12 50 wt¾). The polymer had 1.6 wt¾ of bromine residue. As the mixing ratio of 2,5-dibromothiophene to tetrabromothiophene decreased, yield of the polymer decreased. A polymer from tetrabromothiophene gave yield of 41 %. As for electric conductivity, the polymer prepared from only 2,5-dibromothiophene gave a higher value than copolymers of 2,5-dibromothiophene and tetrabromothiophene. Increasing the a mixing ratio of tetrabromothiophene caused a decrease of the conductivity. The polymer from tetrabromothiophene gave electric conductivity of -10-6 -10-7 Scm-1 (1 2 20wt%).KEY WORDS Poly(thiophene) / 2,5-Dibromothiophene / Tetrabromothiophene / Palladium / Reductive Polymerization / of these polymers were measured.