Synthesis and characterization of red phosphorescent-conjugated polymers containing charged iridium complexes and carbazole unit

A series of homogeneous red-light phosphorescent polymers with charged iridium (Ir) complex in the backbones and carbazole unit on the side were synthesized by Suzuki polycondensation. These polymers are made up of three repeat units: (i) charged iridium (Ir) complex; (ii) 9,9-dihexylfluorene; (iii) 9,9-bis(N-carbazolyl-hexanyl)-fluorene. Their structures have been identified by nuclear magnetic resonance (NMR) and elemental analysis. All chelating polymers displayed good thermal stability, redox reversibility and film formation. Compared with our former study on these charged Ir complex containing polymers, the addition of carbazole unit has a strong influence on their hole injection and charge attraction ability as well as the host-guest energy transfer efficiency.