Synthesis of electrophosphorescent polymers based on para-phenylenes with iridium complexes

A series of hyper-branched and linear-type conjugated polymers based on substituted para-phenylenes with iridium complexes was synthesized by Yamamoto polycondensation. The efficient energy transfer from polypara-phenylene segments to iridium complex is observed. EL emission from PPP segments is completely quenched at as low as 0.5 mol % of the Ir complex content in feed ratio. The hyper-branched copolymers emit green light, and the maximal external quantum efficiencies are around 1.5% for BHPPPIrPPy copolymers. CNPPPIrMPPy(acac)-1 copolymer emits yellow light with a maximal external quantum efficiency of 1.3%.