Tuning colorful luminescence of iridium(III) complexes from blue to near infrared

Abstract Five cyclometalated Ir(III) complexes with high phosphorescence efficiencies have been synthesized from 1,3-bis(1-propyl-1 H -benzo[d]imidazol-2-yl)benzene (Pro-MBImB) or 2-(2,4-Difluorophenyl)pyridine (Fppy) based ligands with different ancillary ligands. It was found that these complexes have a wide range of emitting wavelength, covering the whole visible region, with moderately long lifetime (81–2159 ns) and high quantum yield (75–89%). Especially, the introduction of electron withdrawing −COOEt group onto the ancillary ligand extends the emission wavelength and affords good red-light emitting properties, and the obtained CIE (Commission Internationale de L'Eclairage) coordinates of (0.69, 0.31) in complex 2 are close to the standard red light and approaching near infrared region.