物理化学学报 >> 1993, Vol. 9 >> Issue (06): 788-790.doi: 10.3866/PKU.WHXB19930612

研究论文 上一篇    下一篇

气态丙烯酸光致脱羧反应AM1法研究

方维海; 方德彩; 刘若庄   

  1. 北京师范大学化学系,北京 100875
  • 收稿日期:1992-05-12 修回日期:1992-10-12 发布日期:1993-12-15
  • 通讯作者: 刘若庄

AM1 Study of the Photodecarboxylation Reaction of Acrylic acid in the Gas Phase

Fang Wei-Hai; Fang De-Cai; Liu Ruo-Zhuang   

  1. Department of Chemistry, Beijing Normal Univeristy, Beijing 100875
  • Received:1992-05-12 Revised:1992-10-12 Published:1993-12-15
  • Contact: Liu Ruo-Zhuang

摘要: 半经验的自洽场分子轨道法(AM1)被用来研究激发单态(~1ππ~*)和三态(~3ππ~*)丙烯酸的脱羧反应. 计算结果支持Robert等人提出的光解机理. 与实验结合. 进一步推测, 丙烯酸光致脱羧反应的第一步, 是沿单态途径进行, 第二步沿三态途径进行. 单态和三态反应途径中的反应物、过渡态、中间体和产物都用能量梯度技术进行了优化. 对于过渡态和中间体, 还作了振动分析, 确证它们分别是一级鞍点和能量极小值点.

关键词: 丙烯酸, 光致脱羧反应, 半经验自洽场分子轨道法

Abstract: In this parper, the decarboxylation reaction of acrylic acid in the singlet and triplet excited states were investigated by semi-empirical self-consistent-field molecular orbital method (AM1). Our results support the mechanism of photolysis proposed th Robert. In combintion with experiment, it can be deduced that the first step of photodecarboxylation reaction is in the singlet pathway, the second step in triplet pathway. The reactants, transition states, reaction intermedi-ates and products corresponding to the singlet and triplet pathways were optimized by gradient techniques. All of the transition states and intermediates were confirmed by full vibrational analysis.

Key words: Acrylic acid, Photodecarboxylation reaction, Semi-empirical self-consistent-field molecular ordital method