Synthesis and optical properties of quinoxaline-containing poly(aryl ether)s

Three novel poly(aryl ether)s were synthesized from the reaction of three bisphenols with 2,3-bis(4-fluorophenyl)-quinoxaline via nucleophilic aromatic substitution. The polymers contained electron transporting and emissive moieties separated by ether linkages. Quinoxaline was used as electron transporting segment, while p-distyrylbenzene, 2,6-distyrylpyridine and p-quinquephenyl were used as emissive segments. The low reactivity 2,3-bis(4-fluorophenyl)-quinoxaline towards nucleophilic aromatic substitution results in polymers with limited molecular weights. The polymers were soluble in polar organic solvents and strong organic acids. In THF solutions the polymers showed absorption maxima at 349–354 nm and emission maxima at 417–454 nm, with quantum yields of 22–41%. In solid state the polymers showed absorption maxima at 350–353 nm and emission maxima at 427–461 nm. The optical properties of polymers were influenced by intrachain interactions in solution, while interchain interactions were important in solid state.