Photophysical properties of mono- and di-nuclear platinum(II) complexes with the tridentate ligand 2-phenyl-6-(1H-pyrazol-3-yl)-pyridine: A DFT and TDDFT study

摘要

The luminescent cyclometalated platinum(II) complex [Pt(HL)Cl] (1) (where HL=2-phenyl-6-(1H-pyrazol-3-yl)-pyridine anion) and its deprotonated dimer complex [Pt_2(L)_2] (2) were theoretically studied via density functional theory (DFT) and time-dependent DFT (TDDFT) in conjunction with the polarizable continuum model (PCM) solvent effect to investigate their molecular geometries (at the S_0, S_1, and T_1 states), electronic structures, and photophysical properties (absorption and phosphorescence spectra) and to elucidate the reason for the significantly higher phosphorescence quantum yield of 2 (59%) compared to that of the 1 (14%).