【摘要】 以合成的重要荧光材料3-甲基-7-二乙氨基-1,4-氧氮杂萘-2-酮为例子,进行了一些有机含氮杂环化合物的红外、核磁性质Hartree-Fock(HF)和密度泛函(DFT)量子化学从头计算研究。通过系统构象搜寻,对低能量稳定构象进行了红外振动频率和1H、13C-NMR及偶合常数等光谱学性质的计算,并对计算结果进行详细的归属和解析。在化学位移计算方面,HF／631g(d)和DFT／BG3LYP／6311+g(2d,p)方法计算结果相当。但对于自旋偶合常数的计算,用HF／631g(d)方法不能得到准确的结果,只能用密度泛函大基组的方法才能得到比较准确的结果。计算结果表明有机分子光谱性质的理论计算尤其是核磁性质的计算是一种非常有效的辅助结构确定方法。更多还原

【Abstract】 The property of IR and NMR Spectrum for one kind of most important fluorescence compound 3-methyl-7-diethylamino-l ,4-benzoxazin-2-ketone has been calculated by ab initio method Hartree-Fock( HF) with 6-31g( d) basis set and Density functional theory ( DFT/B3LYP) with 6-311 +g(2d,p) basis set in gas-phase. On the basis of the optimized geometries, the vibrationl frequencies and 1H,13C-NMR chemical shift and spin-spin coupling constant of tide compound were predicted and particularly explained. Although the calculated result of HF/6-31g(d) is comparatively with that of DFT/B3LYP/6-311 +g(2d,p) in the calculation of chemical shift, but it can’t be used to the calculation of spin-spin coupling constant for uncorrectable error. DFT/B3LYP/6-311 + g(2d,p) can be applied in the calculation of spin-spin coupling constant and obtained agreetment results with experiment. The results indicated that the DFT method are an excellent means to help us to clarify the molecular structure of organic compounds.更多还原