物理化学学报 >> 1996, Vol. 12 >> Issue (09): 830-835.doi: 10.3866/PKU.WHXB19960911

研究论文 上一篇    下一篇

丙烯醛及其衍生物基态脱羰反应机理的理论研究

邵国泉,方维海,陈光巨,刘若庄   

  1. 北京师范大学化学系,北京 100875
  • 收稿日期:1996-04-23 修回日期:1996-06-12 发布日期:1996-09-15
  • 通讯作者: 刘若庄

Theoretical Study on Decarbonylation Reaction of Acrolein and Its Derivatives in Their Electronic Ground States

Shao Guo-Quan,Fang Wei-Hai,Chen Guang-Ju,Liu Ruo-Zhuang   

  1. Beijing Normal University,Department of Chemistry,Beijing 100875
  • Received:1996-04-23 Revised:1996-06-12 Published:1996-09-15
  • Contact: Liu Ruo-Zhuang

摘要:

用从头算自洽场分子轨道方法和能量梯度技术,研究丙烯醛及其衍生物基态脱羰反应的机理,用二级微扰方法考虑电子相关效应.结果表明基态丙烯醛脱羰为一简单反应,反应涉及三中心过渡态.取代基对丙烯醛脱羰反应仅有较小的影响,从计算的势垒可以推得基态丙烯醛及其衍生物热脱羰是很困难的,但是,光激发得到的丙烯醛很可能首先通过内转换成系间窜跃回到基态,然后发生脱羰反应,即基态脱羰很可能在其光解离反应机理中起着重要作用.

关键词: 丙烯醛, 脱羰反应, 自治场分子轨道方法

Abstract:

In this paper, decarbonylation reaction of acrolein and its derivatives in their electronic ground states were investigated by restricted Hartree-Fock SCF method with energy gradient technique at the level of 3-21G basis set. Electron correlation was considered at the second-order perturbation level. It has been found that decarbonylation reaction of acrolein is a simple reaction involving a three-centered transiton state which has been ascertained by frequency analysis. The potential barrier of decarbonylation reaction of acrolein is 435.1kJ•mol-1, the substituting groups have a little influence on the potential barrier of reaction. The decarbonylation reactions of acrolein and its derivatives in their electronic ground states are difficult to take place, but the ground-state decarbonylation probably plays an important role in the mechanisms of the photo-decarbonylation of acrolein.

Key words: Acrolein, Decarbonylation reaction, Hartree-Fock SCF method