Color tuning of red phosphorescence: New iridium complexes containing fluorinated 2,3-diphenylquinoxaline ligands

The new iridium complexes containing a derivative of 2,3-diphenylquinoxaline as an emitting ligand were synthesized, and their photophysical properties were investigated. The complexes prepared in this study were bis(6-F-2,3-di(p-fluorophenyl) quinoxalinato)iridium acetylacetonate (Ir(6-F-2,3-dpqx-F2)2(acac)) and bis(6-F-2,3-di(p-fluorophenyl)quinoxalinato)iridium pyrazolonates (Ir(6-F-2,3-dpqx-F2)2(przl1) and Ir(6-F-2,3-dpqx-F2)2(przl2)). Their photoluminescence maxima appeared at 638, 632 and 630 nm, respectively. The electroluminescence study revealed that the CIE coordinates of the devices containing Ir(6-F-2,3-dpqx-F2)2(acac) and Ir(6-F-2,3-dpqx-F2)2(przl2) as a light-emitting dopant were (0.675, 0.313) and (0.685, 0.310), respectively, very close to those of the saturated standard red emission.