No abstract

Conjugated polymers were prepared by electroreduction of aryl dihalides in presence of nickel complexes as catalysts. For instance, poly( I ,4-phenylene) was obtained from 4,4'-dibromobiphenyl in high yield (85%). According to the coupling mechanism and to IR spectra, the chains of the polymer are expected to have regular para-linkages and an average length ranging from 6 to I8 phenylene units. The effects of temperature, nature of monomer, catalyst and electrolyte on the yields and on the properties of the polymer were explored.

Homogeneous films of poly(l,4phenylene) (PPP) can be deposited on various materials by electro-reduction of 4,4'-dibromobiphenyl in presence of a nickel complex catalyst. UV and IR spectra indicate that the polymer has a regular structure (exclusively 1,4phenylene units) and an unusual average molecular weight. The nascent PPP films are obtained in their neutral form and can be either reduced or oxidized.