Synthesis, Structures and Photophysical Properties of Cationic Cyclometalated Iridium(III) Complexes Bearing N‐Phenylcarbazole Group

Four cationic cyclometalated IrIII complexes [(MeOPCz)2Ir(bpy)]PF6 (3), [(MeOPCz)2Ir(dtb‐bpy)]PF6 (4), [(TFPCz)2Ir(bpy)]PF6 (5), and [(TFPCz)2Ir(dtb‐bpy)]PF6 (6) were successfully synthesized using two new cyclometalated ligands 9‐phenyl‐3‐(4‐methoxypyridin‐2‐yl)‐9H‐carbazole (MeOPCz) 1 and 9‐phenyl‐3‐(4‐trifluoromethylpyridin‐2‐yl)‐9H‐carbazole (TFPCz) 2 in combination with 2,2'‐bipyridine (bpy) and 4,4'‐di‐tert‐butyl‐2,2'‐bipyridine (dtb‐bpy) as ancillary ligands. These complexes adopt the distorted octahedral configuration, and the complexes 5 and 6 crystallize in the centrosymmetric space group C2/c. Emission wavelength of these complexes can be tuned from 583 nm to 628 nm by the substituents (methoxy, trifluoromethyl and tert‐butyl groups) in ligands. All of these complexes show relatively high emission efficiencies (0.28–0.41) and short lifetimes (0.242–0.461 μs).