化学学报 ›› 2008, Vol. 66 ›› Issue (13): 1529-1533. 上一篇    下一篇

研究论文

亚硝基苯与甲醛的反应机理和溶剂效应的理论研究

黎安勇* 郑天龙 苗树青   

  1. (西南大学化学化工学院 重庆 400715)
  • 收稿日期:2007-10-10 修回日期:2008-01-10 出版日期:2008-07-14 发布日期:2008-07-14
  • 通讯作者: 黎安勇

Theoretical Studies on the Reaction Mechanism of Nitrosobenzene with Formaldehyde and Solvent Effect

LI, An-Yong* ZHENG, Tian-Long MIAO, Shu-Qing   

  1. (School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715)
  • Received:2007-10-10 Revised:2008-01-10 Online:2008-07-14 Published:2008-07-14
  • Contact: LI, An-Yong

采用密度泛函理论方法RB3LYP/6-311++G(d,p)研究了亚硝基苯与甲醛在单重态势能面上分别在气相和溶剂中的反应机理. 找到两条反应通道: 协同机理和分步机理, 均生成实验产物N-苯基氧肟酸C6H5NOHCHO. 计算结果表明: 亚硝基苯与甲醛在气相中分步机理为主要通道. 采用导电极化连续介质模型研究了反应体系在水、乙醇、乙腈、二氯甲烷、四氢呋喃、环己烷溶液中反应的溶剂化效应, 这些溶剂可降低反应的活化能, 但反应对溶剂的极性不敏感. 无论在气相还是溶剂中, 亚硝基苯与甲醛的分步机理为优势通道.

关键词: 亚硝基苯, 甲醛, 溶剂效应, 极化连续模型

The density functional theory RB3LYP/6-311++G(d,p) was employed to study the mechanism of nitrosobenzene with formaldehyde in gas phase and solvents on a singlet potential energy surface. Two reaction paths, the concerted and the stepwise mechanisms were found, both of which produce the experimental product: N-phenylhydroxamic acid C6H5NOHCHO. The calculated results show that the stepwise mechanism is the most favorable one in the gas phase. The solvent effect of the reaction has been studied using the conductor-like polarizable continuum model respectively in the solvents of water, ethanol, acetonitrile, dichloromethane, THF and cyclohexane. The solvation effect reduces the activation energy, but the reaction of nitrosobenzene with formaldehyde is not sensitive to the solvent polarities. In both gas phase and solvents, the stepwise mechanism of nitrosobenzene with formaldehyde is the most favorable one.

Key words: nitrosobenzene, formaldehyde, solvent effect, polarizable continuum model