A novel approach to light emitting polyarylenes: Cyclization of poly(arylene vinylenes)

A novel synthetic route to fully aromatic phenanthrene-based polymers (homopolymers 3, 4 and alternating copolymers 6, 8) has been developed, involving the oxidative cyclization of appropriate phenylsubstituted poly(arylene vinylenes) 1, 2, 5, 7 as the precursor polymers. The transformation proceeds intramolecularly under mild conditions (ferric chloride hexahydrate, methylene chloride solution, RT). The degree of conversion is proofed to be approximately complete. Due to both, stilbene -> phenanthrene conversion and increase of chain stiffness, the optical and light emitting properties are significantly altered. The new film forming polymers are promising materials for topical electroluminescene or opto-optic (NLO) device applications.