Department of Physics, Faculty of Arts and Sciences, Amasya University, 05100 Amasya, Turkey.
J Phys Chem A. 2011 Dec 1;115(47):13865-76. doi: 10.1021/jp205788b. Epub 2011 Nov 3.
The Schiff base compound (E)-2-[(2-chlorophenyl)iminomethyl]-4-trifluoromethoxyphenol has been synthesized and characterized by IR, UV-vis, and X-ray single-crystal determination. The molecular geometry from X-ray experiment in the ground state has been compared using the density functional theory (DFT) with the 6-311++G(d,p) basis set. The calculated results show that the DFT can well reproduce the structure of the title compound. Using the TD-DFT method, electronic absorption spectra of the title compound have been predicted, and a good agreement is determined with the experimental ones. To investigate the tautomeric stability, optimization calculations at the B3LYP/6-311++G(d,p) level were performed for the enol and keto forms of the title compound. Calculated results reveal that its enol form is more stable than its keto form. The predicted nonlinear optical properties of the title compound are much greater than those of urea. The changes of thermodynamic properties for the formation of the title compound with the temperature ranging from 200 to 500 K have been obtained using the statistical thermodynamic method. At 298.15 K, the change of Gibbs free energy for the formation reaction of the title compound is -824.841 kJ/mol. The title compound can spontaneously be produced from the isolated monomers at room temperature. The tautomeric equilibrium constant is also computed as 3.85 × 10(-4) at 298.15 K for enol↔keto tautomerization of the title compound. In addition, a molecular electrostatic potential map of the title compound was performed using the B3LYP/6-311++G(d,p) method.
(E)-2-[(2-氯苯基)亚氨基甲基]-4-三氟甲氧基苯酚席夫碱化合物已经通过红外光谱（IR）、紫外可见光谱（UV-vis）和 X 射线单晶结构测定进行了合成和表征。在基态下，使用密度泛函理论（DFT）和 6-311++G(d,p)基组对 X 射线实验得到的分子几何结构进行了比较。计算结果表明，DFT 能够很好地再现标题化合物的结构。使用 TD-DFT 方法，预测了标题化合物的电子吸收光谱，并与实验结果确定了良好的一致性。为了研究互变异构稳定性，在 B3LYP/6-311++G(d,p)水平上对标题化合物的烯醇和酮形式进行了优化计算。计算结果表明，其烯醇形式比酮形式更稳定。标题化合物的预测非线性光学性质比脲大得多。使用统计热力学方法获得了标题化合物在 200 至 500 K 温度范围内形成的热力学性质变化。在 298.15 K 时，标题化合物形成反应的吉布斯自由能变化为-824.841 kJ/mol。在室温下，标题化合物可以从孤立的单体自发产生。标题化合物的互变异构平衡常数也计算为 3.85×10(-4)，这是标题化合物的烯醇↔酮互变异构平衡常数。此外，还使用 B3LYP/6-311++G(d,p)方法对标题化合物的分子静电势图进行了计算。
