초록 |
Photodynamic behaviors in Ir(III)-Pt(II) bimetallic complex were differentiated by changing bridging ligand that connect the two metal centers: twisted co-planar (2,3-bis(2-pyridyl)pyrazine, dpp) and fully-planar moiety (4,7-phenanthrolino-5,6:5',6'-pyrazine, ppz). In particular, low-energy excitation (530 nm) makes a clear distinction between photo-induced electron transfer (PET) and hole transfer (PHT) after photo-excitation of bimetallic complex that otherwise would not be able to be achieved under high excitation beam energy. The PHT process was only observed in (dfppy)2Ir-dpp-PtCl. The fast quenching process occurring in the Ir-3MLCT state of (dfppy)2Ir-dpp-PtCl was further investigated by time-resolved photoluminescence (TRPL) and femtosecond transient absorption (TA) spectroscopy. |