Department of Applied Physics, Institute of Engineering and Technology, MJP Rohilkhand University, Bareilly, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 Oct;114:236-55. doi: 10.1016/j.saa.2013.05.051. Epub 2013 May 23.
Quantum chemical calculations of geometric structure and vibrational wavenumbers of 2-[4-(N-dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole (AF51) were carried out by using density functional theory (DFT/B3LYP/6-311G(d,p) method. The fundamental vibrational modes were characterized depending on their potential energy distribution (PED). In order to predict the reactive sites for electrophilic and nucleophilic attacks of the title molecule, electrostatic potential surface has been plotted. The UV absorption spectrum was examined in chloroform solvent and compared with the calculated one in gas phase as well as in solvent environment using TD-DFT/ PCM approach. The (1)H NMR spectra was recorded. Comparison between the experimental and the theoretical results is satisfactory. The thermodynamic properties of the title compound at different temperatures have been calculated. A relationship between molecular structural features, non-linear responses and hyperpolarizability of AF51 has been established using vibrational spectra with emphasis on the role of intramolecular charge transfer mechanism in such organic NLO materials.
采用密度泛函理论（DFT/B3LYP/6-311G(d,p)方法）对 2-[4-(N-十二烷酰氨基)苯基]-5-(4-硝基苯基)-1,3,4-恶二唑（AF51）的几何结构和振动波数进行了量子化学计算。根据其势能分布（PED），对基本振动模式进行了特征化。为了预测标题分子的亲电和亲核攻击的反应位点，绘制了静电势能面。在氯仿溶剂中检查了紫外吸收光谱，并使用 TD-DFT/PCM 方法在气相以及溶剂环境中与计算结果进行了比较。记录了 (1)H NMR 谱。实验结果与理论结果之间的比较令人满意。在不同温度下计算了标题化合物的热力学性质。通过强调分子结构特征、非线性响应和 AF51 的极化率之间的关系，利用振动光谱建立了这种有机 NLO 材料中分子内电荷转移机制的作用。
