Synthesis and the Luminescent Study of the Iridium Complexes Containing 2,3-Diphenylquinoline Derivatives and the New Ancillary Ligand for OLED

摘要

We previously reported that Ir(6-F-2,3-dpqx-(OMe)_2)_2(acac) (6-F-2,3-dpqx-(OMe)_2 = 6-fluoro-2,3-bis(4-methoxylphenyl)quinoxaline) exhibited photoluminescence (PL) and electroluminescence (EL) emission at 645 and 667 nm, respectively. To modulate the emission maxima toward the saturated red chromacity, a new main ligand and its iridium complexes were prepared, and their photophysical properties were investigated. As a main ligand, 6-OMe-2,3-dpqx-(OMe)2 (6-OMe-2,3-dpqx-(OMe)_2 = 6-methoxy-2,3-bis(4-methoxylphenyl)quinoxaline), were designed and synthesized. Acetylacetonate (acac) and pyrazolonates (przls) were also che-lated to the iridium center as an ancillary ligand. The resulting complexes prepared herein were Ir(6-OMe-2,3-dpqx-(OMe)_2)_2(acac), Ir(6-OMe-2,3-dpqx-(OMe)_2)_2(przll) and Ir(6-OMe-2,3-dpqx-(OMe)_2)_2(przl2). The photoluminescence (PL) of these complexes were observed around 660 nm, and their electroluminescence maxima were observed around 650 nm. The PL investigation of the complexes in PMMA (PMMA = poly(methylmetacrylate)) for the. polymer solution process revealed that the emission peaks became broader with the range of 600-850 nm than those of the complexes only.