| 초록 |
The phosphorescence properties of fac-Ir(pmp)3, mer-Ir(pmp)3, fac-Ir(dmpmp)3, and mer-Ir(dmpmp)3 (pmp = 3-methyl-1-phenyl-2,3-dihydro-1H-imidazo[4,5-b]pyridine ,dmpmp = 1-(2',6'-dimethylbiphenyl-2-yl)-3-methyl-2,3-dihydro-1H-imidazo[4,5-b]pyridine) in CH2Cl2 were investigated. At 77 K, the fac-isomers showed blue emission with a vibronic structure, while the mer-isomers showed less structured emission. At 300 K, all complexes showed broad and markedly red-shifted emission spectra. The quantum yields of the Ir(dmpmp)3 isomers were low, and their emission lifetimes were short compared to those of Ir(pmp)3. We performed femtosecond time-resolved transient absorption (TA) spectroscopic measurement. The TA spectra of Ir(dmpmp)3 were same as those of Ir(pmp)3 at a short delay time. However, Ir(dmpmp)3 showed a new broad TA band at 720 nm with increasing delay time. The rise time of this band was ca. 10 ps for both isomers. |
