波谱学杂志 ›› 1994, Vol. 11 ›› Issue (4): 369-375.

• 研究论文 • 上一篇    下一篇

直接键连原子间的NMR偶合常数的自然杂化轨道研究IV、13C-15N和13C-19F核自旋偶合常数1JCN1JCF

胡振明1,2, 湛昌国2   

  1. 1. 湖北师范学院化学系, 黄石 435002;
    2. 华中师范大学化学系, 武汉 430070
  • 收稿日期:1993-08-25 修回日期:1994-01-14 出版日期:1994-12-05 发布日期:2018-01-20
  • 基金资助:
    国家自然科学基金资助项目并获湖北省教委科研基金

THE STUDY OF THE MUCLEAR SPIN-SPIN COUPLING CONSTANTS BETWEEN DIRECTLY BONDED ATOMS BY NATURAL HYBRID ORBITALS Ⅳ 13C-15N and13C-19F Nuclear Spin-Spin Coupling Constants 1JCN and 1JCF

Hu Zhenmin1,2, Zhan Changguo2   

  1. 1. Department of Chemistry, Hubei Normal University, Huangshi 435002;
    2. Department of Chemistry, Central China Normal University, Wuhan 430070
  • Received:1993-08-25 Revised:1994-01-14 Online:1994-12-05 Published:2018-01-20

摘要: 首次报道了直接计算偶合常数1JCN1JCF的线性关系式,结果表明,1J(CN)和1JCF主要由成键原子的轨道杂化作用和键极性这两种结构因素所决定,且偶合相互作用中的Fermi接触项仍是最主要的.为从简单价键理论角度解释并计算JCN和JCF的值提供了简便直观的方法.

关键词: 核自旋-自旋偶合, 偶合常数, 杂化轨道, s轨道成份, 净电荷

Abstract: The good relationships are presented which permit efficient calculation of the 13C-15N 13C -13N and 13C-19F nuclear spin-spin coupling constants. The method is applied with with the CNDO/2 molecular orbital approximation and natural hybrid orbitai scheme to a number of substituted hydrocarbons.Generally good agreement with the experimental data supports the idea that the hybridization and bond polarity,and the Fermi contact term are do minant factors in determining carbon-nitrogen and carbon-fluorine spin-spin coupling constants across one bond.This pennits us to interpret and calculate the 1JCN and 1JCF values based on he simple valence bond theory.

Key words: Nuclear spin-spin coupling, Coupling constant, Natural hybrid orbital, s-Character, Net atomic charge