A copolymer of benzene and substituted benzene, particularly anthracene is disclosed. The copolymer is soluble in common organic solvents like chloroform, methylene chloride, benzene, toluene, dimethylformamide, N-methyl pyrrolidinone etc unlike the parent polymer poly-p-phenylene which is highly insoluble in organic solvents. The copolymer is thermally stable up to 380.degree. C. and environmentally stable for at least 1 year. The copolymer is capable of being thermally evaporated useful for electroluminescent devices. The copolymer shows electroluminescene and can be used in the fabrication of an organic light emitting diode device.