联吡啶钌配合物[Ru(Htcterpy)X_3]^(3-)[X=NCS,CN,Cl]的电子结构和光谱性质的理论研究

Theoretical Studies on Electronic Structures and Spectroscopic Properties of [Ru(Htcterpy)X_3]^(3-)[X=NCS,CN,Cl]

利用DFT中的B3LYP方法优化了3个联吡啶钌配合物[Ru(Htcterpy)X3]3-[tcterpy=4,4′,4″-tricar-boxy-2,2′∶6′,2″-terpyridine,X=NCS(1),CN(2),Cl(3)]的基态几何结构,得到的几何参数与实验结果吻合得很好.采用TD-DFT方法,得到了配合物1~3在气态和溶液(乙醇溶液和水溶液)中的激发态电子结构和电子吸收光谱.利用SCRF方法中的CPCM模型来模拟溶剂化效应.研究结果表明,配合物1~3在气态和溶液中的吸收跃迁性质相似,低能吸收均被指认为MLCT和LLCT的混合跃迁,高能吸收均被指认为三联吡啶配体内的π→π*跃迁.溶剂化效应使配合物1~3在溶液中的吸收光谱蓝移.

The ground-structures of [ Ru （Htcterpy） X3]^3 - [ X： NCS （ 1 ）, CN （2）, C1（3）, tcterpy ： 4,4 , 4″-tricarboxy-2,2：6 ,2″-terpyridine, ] are optimized by DFT method（B3LYP）. The calculated geometry parameters are in agreement with the experimental values. Absorption spectra in gas phase and in solutions （ethanol and water） are predicted at the TD-DFT/B3LYP level. The solvent effects are seriously considered by using the conductor-like polarizable continuum model（CPCM）. For complexes 1--3, in gas phase and solution, the low-energy absorptions have a mixed MLCT/LLCT character, whereas the high-energy absorption are attributed to the intra-ligand π→π＊ charge transfer transitions. Our calculations reveal the blue-shift of the absorption spectra in solution with respect to those in gas phase, agreeing with experimental observations.