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含噻二唑环偶氮类芳香有机化合物具有良好的有机非线性光学性能.采用密度泛函理论B3LYP方法和6-311++G(d,p)基组对6个噻二唑衍生物分子进行结构优化与频率计算,运用含时密度泛函理论对其吸收光谱进行理论计算,采用有限场方法及自编程序计算其三阶非线性光学性质(NLO).结果表明,6个分子的吸收波长在361~383nm范围内,属于近紫外区.组成噻二唑衍生物分子的羟基苯环与噻二唑环均不共面,-CH3或Cl引入到羟基苯环的邻、间、对位后,其共面程度与三阶NLO系数γ均按邻、间、对位取代递减.同一位置,引入-CH3比引入Cl原子的三阶NLO系数γ大.因此,在羟基苯环的邻位引入较强的供电子基,可以设计成为良好的三阶非线性光学材料.
Containing thiadiazole ring azo aromatic compounds with good organic nonlinear optical properties. Using density functional theory B3LYP method and 6-311 ++ G (d, p) group of six thiadiazole derivative molecules The structure optimization and frequency calculation were carried out. The absorption spectra were calculated by time-dependent density functional theory and the third-order nonlinear optical properties (NLO) were calculated by finite field method and self-programming. The results showed that the absorption of six molecules The wavelength is in the range of 361-383nm and belongs to the near ultraviolet region.The hydroxybenzene rings and thiadiazole rings which constitute the thiadiazole derivatives are not coplanar, and -CH3 or Cl is introduced into the o-, m-, p- , The degree of coplanarity and the third-order NLO coefficient γ are all decreased by ortho, mers and para substitutions. At the same position, the incorporation of -CH 3 is larger than the third-order NLO coefficient γ of introduction of Cl atoms. Therefore, The introduction of a strong electron donor can be designed to be a good third-order nonlinear optical material.