New synthetic approach to the preparation of polyphenyleneethynylenes and polyheteroaryleneethynylenes

Polyphenyleneethynylenes and polyheteroaryleneethynylenes-polymers with promising electro-optical properties - are usually prepared by the interaction of dihaloaromatic and diethynylaromatic compounds catalysed with transition metal (first of all, Pd) derivatives. Because of the side reactions these procedures often lead to the formation of relatively low molecular weight polymers; in addition, preparation of organo-soluble polyphenyleneethynylenes and polyheteroaryleneethynylenes seems to be rather problematic. In the framework of the present investigation we have developed a new synthetic approach to the preparation of polyphenyleneethynylenes and polyheteroaryleneethynylenes. This approach is based on the utilization of acetylene-containing monomers (e.g. bis-alpha -diketones, bis-cyclopentadienones and diacetylenearylenes) in smoothly-proceeding polymer-forming reactions (the formation of polyphenylquinoxalines and phenylated polyphenylenes). This approach leads to the preparation of high molecular weight polyphenyleneethynylenes and polyphenylquinoxalineethynylenes combining solubility in organic solvents with film-forming properties.