Rational design and synthesis of cationic Ir(III) complexes with triazolate cyclometalated and ancillary ligands for multi-color tuning

Abstract Triazole-type ligand has been approved to be an excellent building block to construct efficient cationic Ir(III) dyes. Herein, a new family of Ir(III) complexes employing two different triazole fragments as cyclometalated and ancillary ligands, respectively, has been synthesized and their photophysical and electrochemical properties are investigated in detail. Through careful modification of the used ligands, efficiently tuning emission color from deep-blue (459 nm) to red (649 nm) is realized and the intrinsic structure-property relationship is also studied by the comprehensive theoretical calculations. Choosing a greenish blue emitting dye 3 that shows relatively high photoluminescence yield in neat film, the solution-processed single-layer device with peak current efficiency of 2.19 cd A −1 and power efficiency of 0.97 lm W −1 , respectively, has been achieved.