直接键连C-C键核自旋偶合常数的量子化学计算

Calculation of the Nuclear Spin-Spin Coupling Constants of Directly Bonded Atoms of C-C

利用PM3级别上的最大重迭对称性分子轨道法对26个化合物进行构型优化。结合自然杂化轨道方法和最大键级杂化轨道方法,计算了其杂化轨道,由此拟合出计算C-C键偶合常数的简单关系式,计算了各种烃类分子中不同的C-C键偶合常数,计算值和实验数据较为吻合,为从简单价键理论角度解释和计算1JCC提供了一种简便直观的方法。

Geometric configurations of the twenty-six compounds were optimized with the maximum overlap symmetry molecular orbital（MOSMO） method under PM3 approximation,and the natural hybridized orbital（NHO） procedure and the maximum bond order hybridized orbital（MBOHO） are performed respectively.Further,the correlativity between the NHO and MBOHO calculation results and the nuclear spin-spin coupling constants of the directly bonded C-C bonds is obtained.The calculated values are all in good agreement with the experimental data,thus one is able to interpret and calculate the 1JCC values based on the simple valence bond theory.