Abant Izzet Baysal University, Department of Physics, Bolu, Turkey. parlak
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Jun;79(1):263-71. doi: 10.1016/j.saa.2011.02.057. Epub 2011 Mar 8.
This study deals with the identification of a title compound, 3-[(2-morpholinoethylimino)methyl]benzene-1,2-diol by means of quantum chemical calculations. The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments, thermodynamic properties, charge analyses, nuclear magnetic resonance (NMR) chemical shifts and ultraviolet-visible (UV-vis) spectra of the title molecule in the ground state were evaluated using density functional theory (DFT) with the standard B3LYP/6-311++G(d,p) method and basis set combination for the first time. Theoretical vibrational spectra of the title compound were interpreted with the aid of normal coordinate analysis based on scaled density functional force field. The results show that the obtained optimized geometric parameters (bond lengths, bond angles and bond dihedrals) and vibrational frequencies were observed to be in good agreement with the available experimental results. Moreover, the calculations of the electronic spectra, (13)C and (1)H chemical shifts were compared with the experimental ones. Furthermore, we not only simulated the frontier molecular orbitals (FMO) and molecular electrostatic potential (MEP) but also determined the transition states and energy band gaps, as well. It was found that charge analyses supported the evidences of MEP. Infrared intensities and Raman activities were also reported.
本研究通过量子化学计算鉴定了标题化合物 3-[(2-吗啉乙基亚氨基)甲基]苯-1,2-二醇。首次采用密度泛函理论(DFT)与标准 B3LYP/6-311++G(d,p)方法和基组组合,对标题分子在基态下的优化分子结构、振动频率及相应的振动归属、热力学性质、电荷分析、核磁共振(NMR)化学位移和紫外-可见(UV-vis)光谱进行了评估。借助基于比例密度泛函力场的正则坐标分析,对标题化合物的理论振动光谱进行了解释。结果表明,所得优化的几何参数(键长、键角和键二面角)和振动频率与实验结果吻合较好。此外,还比较了电子光谱、(13)C 和(1)H 化学位移的计算值与实验值。此外,我们不仅模拟了前沿分子轨道(FMO)和分子静电势(MEP),还确定了过渡态和能带隙。结果表明,电荷分析支持 MEP 的证据。还报道了红外强度和拉曼活性。