有机化学 ›› 2003, Vol. 23 ›› Issue (2): 207-211. 上一篇    下一篇

研究论文

烷烃中碳氢键离解能的估算及其应用

曹晨忠;林原斌   

  1. 湘潭大学化学学院,湘潭(411105)
  • 发布日期:2003-02-25

Evaluation of bond dissociation energy for carbon-hydrogen bond in alkane and its application

Cao Chenzhong;Lin Yuanbin   

  1. Institute of Chemistry,xiangtan University,Xiangtan(411105)
  • Published:2003-02-25

将烷烃中的C-H键看成氢原子H与烷基Ri相连接而成的Ri-H键,以烷基的 HOMO能级和氢原子的轨道能来关联Ri-H键的离解能BDE。研究表明,烷烃分子中 Ri-H键的离能BDE与烷基Ri的极化效应指数PEI(Ri)有良好的线性关系:BDE= c+dPEI(Ri)。所得方程具有良好的估算精度。烷基Ri极化效应指数PEI(Ri)在羟 基自由基与烷烃反应速度常数的定量相关中,也得到良好的应用。

关键词: 烷烃, 极化, 应用, 反应速度常数

The R-i-H bond can be treated as the combination of alkyl radical R; with hydrogen atom H. The bond dissociation energy (BDE) of R-i-H was related to the HOMO energy level of alkyl radical and the atom orbital energy of hydrogen atom. The results showed that a good linear correlation was found between the BDE of R-i-H and the polarizability effect index (PEI) of alkyl radical R: BDE = c + dPEI(R;) . The expression has good precision for evaluating the BDEs of C-H bonds. Moreover, the PEI of alkyl radical R,- can be corelated quantitatively with the reaction rates of alkane with hydroxyl radicals.

Key words: ALKANE, POLARIZATION, APPLICATION, REACTION RATE CONSTANT

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