系列二亚胺Os(Ⅱ)配合物[Os(L)_2(CN)_2(phen)](L=PH_3,DMSO;phen=1,10-邻二氮杂菲)及[Os(PH_3)_2(phen)Br_2]电子结构和光谱性质的理论研究

Theoretical Studies on the Electron Structures and Spectroscopic Properties of Diimine Os(Ⅱ) Complexes [Os(L)_2(CN)_2(phen)](L=PH_3,DMSO;phen=1,10-phenanthroline) and [Os(PH_3)_2(phen)Br_2]

采用自旋限制和非限制B3LYP/UB3LYP方法分别优化了系列Os(Ⅱ)二亚胺配合物[Os(L)2(CN)2(phen)][phen=1,10-邻二氮杂菲;L=PH3(1),二甲基亚砜(DMSO)(2)]及[Os(PH3)2(phen)Br2](3)的基态和激发态几何构型.通过TD-DFT方法结合PCM溶剂化模型计算了配合物1～3在二氯甲烷溶液中的吸收和发射光谱并指认了相应的跃迁性质.通过理论化学计算,揭示了π酸配体及π碱配体对配合物磷光发射性质的影响及原因.并进一步解释了配合物3易于在Os—Br键处断裂而发生反应的量子化学机理.对配合物在不同溶剂中的磷光发射性质的计算表明,溶剂对配合物的量子产率存在着影响并且配合物具有溶剂化显色效应。

The geometrical structures of a series of Os（Ⅱ） diimine complexes [Os（L）2（CN）2（phen）] （phen=1,10-phenanthroline; L=PH3 （1）, DMSO （2）） and [Os（PH3）2（phen）Br2] （3） in the ground state and the lowest-energy triplet excited state were optimized by the restricted and unrestricted B3LYP/UB3LYP methods. The absorption and emission properties and transition characters in dichloromethane solution were predicted at the time-dependent density functional theory TD-DFT level associated with the PCM solvent effect model. The mechanism and the effects of the π-acid and π-alkali ligands on the phosphorescent spectroscopic properties for 1 -3 were explored. As revealed in this paper, complex 3 is prone to break up from the bond Os-Br and the quantum chemical mechanism of potential reaction was further explained. The computed results of 1-3 phosphorescent emission in different solvents indicated that the solvent would affect the quantum efficiencies of the complexes and the solvatochromic effect was observed.