Soluble conjugated copolymers constituted of pyridine and phenylene units

Poly(2,5-dihexyl-1,4-phenylene-alt-2,5-pyridinediyl) (PDHP-2,5-Py) was prepared in a high yield by the Suzuki reaction of 2,5-dihexylbenzene-1,4-bisboronic acid and p-dibromopyridine. The copolymer was soluble in organic solvents such as chloroform, THF and dichloromethane. GPC indicated that it had an average molecular weight of 1.1 x104. A cast film deposited on a platinum plate was used for cyclic voltammetry. The film showed a cathodic peak at −2.2 V (vs. Ag wire). It was green below the reduction potential and transparent in the neutral state.