采用密度泛函理论(DFT)B3LYP方法,对含二茂铁双Schiff碱配体及其Ni(Ⅱ)配合物的几何构型进行优化.在得到稳定构型的基础上,采用含时密度泛函理论(TD-DFT)的B3LYP方法计算了配合物的电子光谱,并结合有限场(FF)方法研究了配体和配合物的极化率和二阶非线性光学(NLO)性质.结果表明,配体中引入Ni(Ⅱ)形成配合物后,极化率α3值变化不大,增加桥的共轭性或加入吸电子取代基,α3值均增大.与配体相比,配合物的二阶NLO系数均增大.双键桥连双Schiff碱配体的βtot值比单键桥连双Schiff碱配体的βtot值大很多,而单、双键桥连双Schiff碱配合物的βtot值接近.二茂铁基团在配体和配合物中的作用不同,在配体中二茂铁有一定的吸电子性,而在配合物中表现出给电子性.%The geomertrical structures of Schiff base ligands containing ferrocene and their Ni( Ⅱ ) complexes were optimized with density functional theory(Dll) B3LYP method. On the basis of the stable structures, the electronic spectrum of complexes were calculated by time-dependent density functional theory (TD-DFT)B3LYP method. The polarizability and second-order nonlinear optical(NLO) properties of ligands and complexes were investigated by combining with the finite-field (FF) method. The results show that the a values do not change significantly from ligands to their Ni( Ⅱ ) complexes, but enhanced by increasing the conjugation bridge and adding withdrawing-electron substituent groups. Moreover, compared with ligands, all complexes have a larger second-order NLO coefficients. The βtot values of the double bond bridge Schiff base ligands are much larger than the single bond bridge ones, but the βtot values of the double bond bridge Schiff base complexes are close to the single bond bridge Schiff base complexes. In addition, ferrocenyl groups have different roles in ligands and complexes, acting as an accepter in ligands but a donor in complexes.
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