Summary: | 碩士 === 國立成功大學 === 化學系碩博士班 === 96 === The research performed in this work involved two kind of bridge ligands, 2,3-bis(2-pyridiyl)-pyrazine (dpp) and 2,2'-bipyrimidine (bpym). Dinuclear cyclometalated complexes of [Ir2(ppy)4(dpp)]2+ (1), [Rh2(ppy)4(dpp)]2+ (2), [IrRh(ppy)4(dpp)]2+ (3), [Ir2(ppy)4(bpym)]2+ (5), [Rh2(ppy)4(bpym)]2+ (6), and [IrRh(ppy)4(bpym)]2+ (7) and mononuclear cyclometalated complexes of [Ir(ppy)2(dpp)]+ (4) and [Ir(ppy)2(bpym)]+ (8) were synthesized with bridge ligand. The structure of these cyclometalated complexes were identified by X-ray diffraction crystallography and spectroscopic data. The photophysical and electrochemical properties were characterized. Density functional theory (DFT) calculations were also employed to study the orbital distribution.
It was found that the orbital energy of HOMO and LUMO, the electrochemical redox potential, and MLCT bands in UV-Vis absorption spectra.changed with ligands complexing to different metal. For complexes 1 and 2, the dihedral angle of bridge ligand was found to affect the reduction potential.
|