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| Type |
Poster Presentation |
| Area |
공업화학 |
| Room No. |
포스터발표장 |
| Time |
4월 20일 (목요일) 11:00~12:30 |
| Code |
IND.P-7 |
| Subject |
Optical Properties of Heteroleptic Ir complexes: Ligand-to- ligand Charge Transfer of Metal Complexes |
| Authors |
박재현, 강상욱, 손호진*
고려대학교 신소재화학과, Korea
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| Abstract |
Through the synthesis that two types of heteroleptic Ir complexes (Ir(dfppy)2(tpphz)) and (Ir(dfppy)2(dpq)), we found the electronic spectra of metal complexes which contain a reducing and an oxidizing ligand (Lred–M–Lox) are characterized by ligand-to-ligand charge transfer (LLCT) absorptions. Because of the tpphz and dpq ligands π-conjugation are longer than dfppy, ligand-centered(LC) and metal-to-ligand charge transfer(MLCT) states are low. The LLCT from dfppy to tpphz (or dpq) was investigated femtosecond transient absorption (TA) spectroscopy in excitation of dfppy. As the LLCT process have been changed for the TA bands involved with increased of the MLCT states of tpphz or dpq ligand and those of dfppy decreased, LC/MLCT state of dfppy has shown 480 nm. According to the MLCT emission of Ir(ppy)2(tpp hz) showed strong temperature dependence, since the LLCT process has a significant energy barrier. The LLCT process showed 17 ps for Ir(dfppy)2(tpphz) and 5 ps for Ir(dfppy)2(dpq) time constants. As the emission of Ir(dfppy)2(dpq) influenced weakly the temperature, we know LLCT process has a smaller barrier. Moreover, the anomalous rigidochromism and photodynamic behaviours can be explained in terms of the barrier between cyclometalating and ancillary ligands. |
| E-mail |
wogus0618@korea.ac.kr |
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119th General Meeting of the KCS