三种席夫碱-Ni（II）配合物的电子结构和吸收光谱的理论计算

摘要

Geometry optimizations and frequency calculations of three Ni(II)metal complexes with tetradentate Schiff base ligands in the ground state were performed at B3LYP/6-31 +G (d)-LANL2DZ level,and the characteristics of the stationary points were determined.On the basis of the optimized geometries,the absorption spectra of the three complexes were calculat-ed in N,N-dimethylformamide solvent by using time-dependent density functional theory (TD-DFT)at the TD-B3LYP/6-31+G(d)-LANL2DZ level in association with the polarized continu-um model (PCM).Calculation results indicate that the energy gap between the HOMO and LUMO is enlarged because of the existence of m-methoxyl group,which results in the red-shift of the lowest-lying absorption bands of the three Ni(II)complexes in the sequence of A→B→C.%采用 B3LYP/6-31+G(d)-LANL2DZ 方法优化了三种 Ni(II)的席夫碱配合物基态的几何构型,并在相同水平下进行了频率分析以确认稳定点的性质；利用含时密度泛函理论和极化连续介质模型(PCM),按 TD-B3LYP/6-31+G(d)-LANL2DZ 水平计算了目标配合物在 N,N-二甲基甲酰胺溶剂中的电子结构和吸收光谱。计算结果表明,配体中间位甲氧基的存在使配合物 A 具有较大的 HOMO-LUMO 能级差；且三种 Ni(II)配合物的 S0→S1态的跃迁能按照 A→B→C 的顺序依次降低。