Department of Physics, Faculty of Sciences, Selçuk University, 42049 Campus, Konya, Turkey.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 May;75(5):1492-6. doi: 10.1016/j.saa.2010.02.004. Epub 2010 Feb 11.
(E)-N-(4-Nitrobenzylidene)-2,6-dimethylaniline (1) and (E)-N-(4-nitrobenzylidene)-2,3-dimethylaniline (2) have been synthesized. The crystal structures of both compounds have been defined by X-ray diffraction analysis. The maximum one-photon absorption (OPA) wavelengths recorded by quantum mechanical computations using a configuration interaction (CI) method are estimated in the UV region to be shorter than 450nm, showing good optical transparency to the visible light. To provide an insight into the microscopic third-order nonlinear optical (NLO) properties of the investigated molecules, both dispersion-free (static) and also frequency-dependent (dynamic) linear polarizabilities (alpha) and second hyperpolarizabilities (gamma) at lambda=825-1125nm and 1050-1600nm wavelength areas have been computed using time-dependent Hartree-Fock (TDHF) method. According to the ab initio calculation results, the title molecules exhibit second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behavior.
(E)-N-(4-硝基苯亚甲基)-2,6-二甲基苯胺（1）和(E)-N-(4-硝基苯亚甲基)-2,3-二甲基苯胺（2）已被合成。通过 X 射线衍射分析确定了这两种化合物的晶体结构。使用组态相互作用（CI）方法进行量子力学计算记录的最大单光子吸收（OPA）波长在 UV 区域估计短于 450nm，对可见光具有良好的光学透明度。为了深入了解研究分子的微观三阶非线性光学（NLO）性质，使用含时 Hartree-Fock（TDHF）方法计算了在 lambda=825-1125nm 和 1050-1600nm 波长范围内无色散（静态）和频率相关（动态）线性极化率（alpha）和二阶超极化率（gamma）。根据从头算计算结果，标题分子表现出具有非零值的二阶超极化率，暗示微观三阶 NLO 行为。
