NMR偶合常数的从头算级别自然杂化轨道研究

摘要

为了研究自然杂化轨道计算结果与核自旋偶合常数的相关性，本文进行了从头算级别的自然杂化轨道计算。采用STO-3G基组，利用Lowdin正交化原子轨道基组下的密度矩阵，得到了分子中各原子的杂化轨道、净电荷与13C-H、13C-13C键自旋偶合常数1JCH和1JCC之间关系式。利用这些式子计算得到的结果与实验数据非常一致。%The ab initio natural hybrid orbital(NHO) procedure has been performed with STO-3G basis set to study the correlativity between the ab initio NHO calculation results and nuclear spin-spin coupling constants.The generalized relationship which involves the contributions of not only the calculated s-character of NHO,but also the net atomic charges,have been applied to obtain relationships for calculation of the nuclear spin-spin coupling constants of various 13C-H and 13C-13C bonds.The coupling constants evaluated by use of these relationships are in good agreement with the experimental data.