Synthesis and photophysical study of heteroleptic iridium(III) complex

다국어 초록 (Multilingual Abstract)

The synthesis and photophysical study of efficient phosphorescent iridium(III) complexes having two different (CˆN) ligands are reported. In order to improve the luminescence efficiency by avoiding triplettriplet (T-T) annihilation, the iridium complex, Ir(ppy)_(2)(dpq), is designed and prepared where ppy and dpq represent 2-phenylpyridine and 2,4-diphenylquinoline, respectively. Two ppy ligands and a dpq ligand act as a source of energy supply. Since Ir(ppy)_(3) and Ir(dpq)_(3)can be placed in the metal-to-ligand charge transfer (MLCT) excited state, they absorb light effectively. When Ir(ppy)_(2)(dpq) is placed in excited state, the excitation energy is not quenched or deactivated but quickly intramolecular transferred from two ppy ligands to one luminescent dpq ligand. This is because the triplet energy level of ppy is higher than that of dpq and light is emitted from dpq ligand in the end. Thus, Ir(ppy)_(2)(dpq) shows strong photoluminescence from dpq ligand. To analyze luminescent mechanism, we calculated these complexes having two different ligand sets theoretically by using computational method.