摘要
在我们提出的^(31)P-NMR化学位移变化的五条经验规律及核外电子云球对称效应原理基础上,建立统一公式计算了迄今还无法计算的各类开环有机磷酸酯^(31)P—NMR化学位移,为计算有机磷化学战剂及农药等各类有机磷酸酯的化学位移和^(31)P—NMR谱-构关系研究提供了基础。这一公式比以往各种化学位移计算方程具有更普遍的意义,在一定程度上揭示了NMR屏蔽结构效应的本质。
The empirical or theoretical calculation of chemical shifts is very important forchemists. Combining our spherical asymmetry effect (ΔX) and local van der Waals steric energy ofthe substituent (E_g) calculated by using Allinger's molecular mechanics MM2 program, we obtainan unified equation representing the substituent effects (α,β,γ,δ…) on ^(31)p-NMR chemical shiftsfor all classes of acyclic organophosphorus esters: δ^(31)P=A+B(δX+ΣE_g)=A+B·w. This equation is found to be widely applicable in substituent effects on chemical shifts ofNMR spectroscopy. The equation, at least in certain extent, brings to light the objective lawgoverning the structural effects of NMR.
出处
《军事医学科学院院刊》
CSCD
北大核心
1993年第2期93-97,共5页
Bulletin of the Academy of Military Medical Sciences
关键词
NMR
统一公式
有机磷酸酯
磷31
~31P-NMR
unified formula
acyclic organophosphorus esters
the van der Waals parameters of groups
calculation of chemical shifts
