A novel blue-emitting Ir(III) complex with short excited state lifetime: Synthesis, structure, photophysical property, and electrophosphorescence performance

In this paper, we synthesize a triphenylamine-derived cyclometalating ligand of (4-benzothiazol-2-yl-phenyl)-diphenyl-amine (referred as BPDA) and its corresponding Ir(III) complex of (BPDA)2Ir(acac) (acac=acetylacetone). The photophysical property, molecular structure, thermal property and electroluminescence performance of (BPDA)2Ir(acac) are investigated in detail. It is found that (BPDA)2Ir(acac) is an efficient emitter with high thermal stability and short excited state lifetime. The emission of (BPDA)2Ir(acac) changes from deep blue (417 nm) to bluish green (500 nm) upon addition of different solvents. We also investigate its electrophosphorescence performance. A maximum electroluminance of 8820 cd/m2 peaking at 494 nm is achieved, with the highest device efficiency of 1.72 cd/A.