Synthesis and Electrochemical Study of the Ir(III) Complexes Containing the Diphenyl-quinoline, -Quinoxaline and Pyrazolonate Ligands

Abstract

Ir(dpq/dpqx)2(przl-R) complexes were prepared and their electrochemical properties were investigated, where dpq, dpqx and przl-R represent 2,3-diphenylquinoline, 2,3-diphenylquinoxaline and N-phenyl-R-pyrazolonate derivatives, respectively. The iridium complexes containing dpq and dpqx as main ligands were reported to show red phosphorescence, and involvement of a pyrazolonate ancillaryligand in the iridium complexes ledto highluminous efficiency for organic light-emitting diodes. In this study, we synthesized red phosphorescent iridium complexes containing a new pyrazolonate ancillary ligand and investigated the HOMOs, LUMOs and resulting electrochemical gaps of Ir(dpq/dpqx)2(przl-R) bycyclic voltammetry.Theemission wavelengths of the complexes at600 -640 nm were consistent with the gaps of 1.95 - 2.03 eV measured from reduction and oxidation potentials of the complexes.