| 초록 |
In order to understand the intrinsic nature of nonradiative processes in heteroleptic cyclometalated Ir(III) complexesThree ancillary ligands, acetylacetonate (acac), picolinate (pic), and tetrakis-pyrazolyl borate (bor), were employed for the preparation of the Ir(III) complexes [Ir(ppySO2F)2(acac)] (Ir-acac), [Ir(ppySO2F)2(pic)] (Ir-pic), and [Ir(ppySO2F)2(bor)] (Ir-bor). The molecular structures were characterized by X-ray crystallography. Blue phosphorescence maxima were observed at 458, 466, and 478 nm for Ir-bor, Ir-pic, and Ir-acac, respectively, at 77 K, and the corresponding emission quantum yields were determined to be 0.79, 0.80, and 0.98 in anaerobic CH2Cl2 at 300 K. We carried out ab initio calculations to evaluate the energy states and their corresponding orbitals. The nonemissive MC states lie at higher energies than the emissive MLCT state, hence the MC states can be excluded from the nonradiative pathway. |
