Synthesis and chemical properties of new photoluminescent poly(p-phenyleneethynylene) containing an electron-accepting benzothiadiazole unit and an electron-donating dialkoxybenzene unit

A new poly(p-phenyleneethynylene) type polymer consisting of an electron-accepting 2,1,3-benzothiadiazole unit was prepared by polycondensation between 4,7-di(4-bromophenyl)-2,1,3-benzothiadiazole and 1,4-didodecyloxy-2,5-diethynylbenzene using Pd(PPh3)4 and CuI as the catalyst. The polymer was soluble in chloroform and showed photoluminescence in solutions and in the solid state. The quantum yield was considerably enhanced by the introduction of the two p-phenylene units at 2,1,3-benzothiadiazole unit. The polymer was electrochemically active and had good heat resistance.