^1^7O, ^3^3S NMR化学位移结构效应的分子力学研究

本文通过对环状磷酸酯和环状亚磷酸酯类化合物的分子力学计算,观察到^1^7ONMR化学位移的变化同时受到氧原子局部范德华相互综合利用(E~V~D~W~-~O)和局部偶极相互作用能(E~i~i~p-~O)的影响。此外,在上述两类化合物中,环外氧原子的δ-压缩效应极为明显,这主要是由于该氧原子局部范德华相互作用能起决定作用的缘故。同时,经对二烷基砜类化合物的分子力学计算,首次获得^3^3SNMR化学位移和硫原子局部范德华相互作用能E~V~D~W~-~S之间良好的线性关系。

Molecular mechanics studies of the structure effect of the ^1^7O and ^3^3S NMR chemical shifts

Molecular mechanics studies of the steric energies of cyclic phosphates and phosphites reveal that the magnitude of the ^1^7O NMR chemical shift is not only determined by the local van der Waals interaction energy, but also influenced by the local dipole interaction energy. Furthermore, the δ-compression effect of the exocyclic oxygen plays an important role in this respect, as the result of the local van derr Waals interactions. As found by us the ^3^3S NMR chemical shift of dialkylsulfones is linearly correlated with the local van der Waals interaction energy, the regression analysis provides an excellant correlation coefficient.