关键词: 密度泛函理论, 8-羟基喹啉, 金属配合物, 非线性光学性质, 电子光谱

Abstract:

Density functional theory with the B3LYP level was used to investigate the nonlinear optical properties of 8-hydroxyquinolinolate (Ag, Pt)(AgQ, PtQ₂) metal complexes and their derivatives. The introduction of substituents resulted in considerable red shifts for the highest absorption wavelength of the Pt complexes. The lowest energy excitation absorption mainly consisted of d→π^* and π→π^* excitations from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO). Metal to ligand charge-transfer (MLCT) and ligand to ligand charge-transfer (LLCT) were mainly involved. Adulteration with the transition metals Pt and Ag resulted in a significant increase in the third-order nonlinear optical coefficient γ of 8-hydroxyquinolinolate. The introduction of ―Ph, ―PhOCH₃, ―PhF₂, and ―PhF₅ further improved the γ value of the 8-hydroxyquinolinolate metal complexes. The gradient of the γ value increased with an increase in the electron-donating ability of the introduced substituent. This gradient was lower for substituent with a higher electron-accepting ability.

Key words: Density functional theory, 8-Hydroxyquinolinolate, Metal complexes, Nonlinear optical property, Electronic spectrum