波谱学杂志 ›› 1997, Vol. 14 ›› Issue (2): 179-184.

• 研究论文 • 上一篇    下一篇

取代基性质与饱和碳及饱和碳上质子化学位移的关系

李临生   

  1. 西北轻工业学院应用化学研究所, 咸阳 712081
  • 收稿日期:1996-08-12 修回日期:1996-10-09 出版日期:1997-04-05 发布日期:2018-01-22

CORRELATION OF CHEMICAL SHIFTS OF SATURATED 13C AND PROTONS ON SATURATED CARBON WITH SUBSTITUENTS

Li Linsheng   

  1. Institute of Applied Chemistry, Northwest Institute of Light Industry, Xianyang 712081
  • Received:1996-08-12 Revised:1996-10-09 Online:1997-04-05 Published:2018-01-22

摘要: 根据多元线性回归分析,得到一个表达去屏蔽参数△αH与基团电负性XG的关系式:XG=(2.6△αH-n)/5+2.6.13C NMR去屏蔽参数△αC与电负性之间的关系可表达为:XG=(△αC+5n)/40+2.由上述二式计算出的基团电负性与文献中提供的数据相仿,说明氢谱和碳谱化学位移主要与取代基电负性及其变形性有线性关系.不过由化学位移或去屏蔽参数计算出的基团电负住不能反映芳环等具有各向异性效应基团的诱导效应.

关键词: NMR, 化学位移, 氢谱, 碳谱, 去屏蔽参数, 基团电负性

Abstract: A simple relation is presented to calculate group electronegativity (XG), viz., XG=(2.6△αH-n)/5+2.6. △αH is the group deshielding parameter in 1H NMR, proposed by author. n is the principal quantum number of center atom in the group. The relation of XG with chemical shift parameter in 13C NMR is also drawn as XG=(△αC+5n)/40+2. The resulting values of electronegativities for some 46 groups/atoms are similar to those obtained in previous papers, but calculated values from deshielding parameters of aromatic ring and anisotropic groups do not stand for their inductive effect. As a result,the principal quantum number of outer layer electrons in molecular orbital, maybe the deformation of MO, is a factor to influence the chemical shift.

Key words: NMR, Chemical shift, Deshielding paramter, Group dectronegativity, 1H NMR, 13C NMR