Demircioğlu Zeynep, Kaştaş Çiğdem Albayrak, Büyükgüngör Orhan
Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey.
Department of Chemistry, Faculty of Arts and Science, Sinop University, TR-57000 Sinop, Turkey.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Mar 15;139:539-48. doi: 10.1016/j.saa.2014.11.078. Epub 2014 Dec 23.
A new o-hydroxy Schiff base, (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile was isolated and investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. The vibrational spectral analysis was carried out by using FT-IR spectroscopy in the range of 4000-400cm(-)(1). Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) basis set. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The UV-vis spectrum of the compound was recorded in the region 200-800 nm in several solvents and electronic properties such as excitation energies, and wavelengths were calculated by TD-DFT/B3LYP method. The most prominent transitions were corresponds to π→π∗. Hybrid density functional theory (DFT) was used to investigate the enol-imine and keto-amine tautomers of titled compound. The titled compound showed the preference of enol form, as supported by X-ray and spectroscopic analysis results. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms. Additionally, geometry optimizations in solvent media were performed with the same level of theory by the integral equation formalism polarizable continuum (IEF-PCM). Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.
一种新型邻羟基席夫碱，（E）-2-[(2-羟基-6-甲氧基亚苄基)氨基]苯甲腈，通过实验和理论方法进行了分离和研究。通过X射线衍射法测定了其固态分子结构。使用傅里叶变换红外光谱仪在4000 - 400cm⁻¹范围内进行了振动光谱分析。采用密度泛函理论（DFT）方法，使用6-31G(d,p)基组进行了理论计算。计算结果应用于标题化合物的模拟光谱，与观测光谱显示出极好的一致性。在几种溶剂中记录了该化合物在200 - 800nm区域的紫外可见光谱，并通过TD-DFT/B3LYP方法计算了激发能和波长等电子性质。最显著的跃迁对应于π→π∗。采用杂化密度泛函理论（DFT）研究了标题化合物的烯醇-亚胺和酮-胺互变异构体。X射线和光谱分析结果表明，标题化合物表现出烯醇形式的偏好。比较了烯醇-亚胺和酮-胺形式的几何和分子性质。此外，通过积分方程形式极化连续介质（IEF-PCM）在相同理论水平下对溶剂介质中的几何结构进行了优化。使用自然键轨道（NBO）分析研究了分子的稳定性，其源于超共轭相互作用、电荷离域和分子内氢键。研究了Mulliken布居方法和自然布居分析（NPA）。还根据轨道电荷计算方法（NPA）获得的电荷计算了凝聚福井函数和相对亲核性指数。还研究了分子静电势（MEP）和非线性光学（NLO）性质。
