论文部分内容阅读
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。
Taking the synthesis of 3-methyl-7-diethylamino-1,4-oxazinan-2-one, an important fluorescent material, the infrared and nuclear magnetic properties of some organic nitrogen-containing heterocyclic compounds were studied. Hartree-Fock HF) and density functional (DFT) ab initio computational studies. Through the systematic conformation search, the low-energy stable conformations were calculated by the infrared vibrational frequency, 1H, 13C-NMR and coupling constants, and the results were detailedly assigned and analyzed. In the chemical shift calculation, the results of HF / 631g (d) and DFT / BG3LYP / 6311 + g (2d, p) are comparable. However, for the calculation of the spin coupling constants, the accurate results can not be obtained by the method of HF / 631g (d), and only the density functional large base group method can be used to obtain more accurate results. The calculation results show that the theoretical calculation of the spectral properties of organic molecules, especially the calculation of the nuclear magnetic properties, is a very effective method for determining the structure of ancillary structures.