SYNTHESIS OF POLY(3-PHENYL-2,5-THIOPHENE) BY NICKEL-CATALYZED COUPLING POLYMERIZATION OF 3-PHENYL-2,5-DICHLOROTHIOPHENE

Poly(3-phenyl-2,5-thiophene) was prepared by the nickel-catalyzed coupling polymerization. Polymerizations were conducted in N,N-dimethylacetamide (DMAc) in the presence of zinc, triphenylphosphine, and bipyridine and produced polymer 4 with inherent viscosities up to 0.50 dL.g-1 under mild conditions. The effects of various factors, such as amount of catalyst and ligand, reaction medium, and reaction temperature, were studied. The microstructure of polymer 4 was investigated by means of C-13 NMR spectroscopy, and it has been found that the polymer obtained had the expected structure without mislinkage through the beta-position and the random structure on regiospecificity. The polymer was readily soluble in common organic solvents and can be processed into uniform films from their solution. The thermogravimetry of polymer 4 showed 10% weight loss at 550 and 570-degrees-C in air and in nitrogen, respectively.