含有Pt―Pt键金属配合物的电子结构和二阶非线性光学性质

采用量子化学密度泛函理论(DFT)结合有限场(FF)的方法对一系列含有Pt―Pt键金属配合物的电子结构和二阶非线性光学(NLO)性质进行了理论计算. 结果表明改变共轭配体对Pt―Pt键影响不大. 由配体到Pt―Pt金属基团的电荷转移强度随配体增长而变大. 金属配合物静态一阶超极化率随配体的增长而增大, 配合物电荷的改变基本不影响这类化合物的二阶NLO性质. 具有相对长的共轭配体的配合物IId具有最大的二阶NLO响应. 含时密度泛函理论(TD-DFT)计算表明配合物IId的二阶NLO响应来自于混有配体到金属的配体内的π→π^*电荷转移跃迁的贡献.

Electronic Structures and Second-Order Nonlinear Optical Properties of a Series of Pt-Pt Bond-Containing Metal Complexes

The electronic structures and second-order nonlinear optical(NLO) properties of a series of Pt—Pt bond-containing metal complexes were calculated using density factional theory(DFT) combined with the finite field(FF) method.The results show that the replacement of a conjugated ligand does not substantially affect the Pt—Pt bond.Additionally,the strength of charge transfer(CT) from the ligand to the metal group increases as the length of the conjugated ligand becomes longer.The first-order hyperpolarizabilities of these metal complexes increase as the length of the conjugated ligand becomes longer but this is not sensitive to the change in charge of these metal complexes.ComplexⅡd containing a relevant longπ-conjugated ligand possesses the largest first-order hyperpolarizability according to our DFT-FF calculations.Time-dependent(TD)-DFT calculations show that theπ→π~* intraligand mixing metal to ligand charge transfer transitions directly contribute to the second-order NLO response of the Pt—Pt bond-containing metal complexⅡd.