苯妥英分子结构、NMR分析、IR光谱的密度泛函理论与第一性原理计算

Molecular Structure, NMR Analysis, IR Spectra of Phenytoin by DFT and Ab Initio HF Calculations

使用Gaussian03软件,利用RHF/6-31++G(d,p)和B3LYP/6-31++G(d,p)方法计算了基态苯妥英(phenytoin,C15H11N2O2)的几何结构、红外与拉曼光谱、谐振强度以及原子电荷分布,并将修正后的谐振频率与傅里叶变换红外光谱实验值进行了对比,对红外光谱和振动模式进行了细致分析和解释。在DFT计算和平均势能分布分析的基础上,对实验得到的苯妥英的振动模式进行解释,并提出了一些其他振动模式,进一步得到了标题化合物的红外光谱图和拉曼光谱图。另外,还研究了苯妥英的^(13)C和~1H NMR谱以及分子的其他性质。

Quantum chemistry calculations were perfo rmed by using Gaussian03 program to compute optimized geometry, harmonic vibrational frequency along with intensities in IR and Raman spectra and atomic charges at RHF/6-31＋＋G（d,p） and B3LYP/6-31＋＋G（d,p） levels for phenytoin（C_（15）H_（11）N_2O_2） in the ground state. The scaled harmonic vibrational frequencies were compared with experimental FT-IR spectra. A detailed interpretation of the infrared spectra of the title compound was reported. Based on the DFT calculation and the results of the PED output obtained from normal coordinate analysis, the vibrational modes of phenytoin from the experiment were interpreted and some other vibrational modes were proposed; furtherly, the theoretical spectrograms for IR and Raman spectra of the title compound were constructed. In addition, the^（13）C and ~1H NMR and other molecular properties were also investigated.