物理化学学报 >> 2007, Vol. 23 >> Issue (02): 217-222.doi: 10.3866/PKU.WHXB20070215

研究论文 上一篇    下一篇

气相中烯丙基负离子与N2O反应机理

刘乐燕;耿志远;赵存元;王永成;李朝晖   

  1. 西北师范大学化学化工学院, 甘肃省高分子材料重点实验室, 兰州 730070
  • 收稿日期:2006-07-17 修回日期:2006-09-29 发布日期:2007-02-01
  • 通讯作者: 耿志远 E-mail:zhiyuangeng@yahoo.com.cn

Gas-phase Reaction Mechanism of Allyl anion with N2O

LIU Le-Yan;GENG Zhi-Yuan;ZHAO Cun-Yuan;WANG Yong-Cheng;LI Zhao-Hui   

  1. Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. China
  • Received:2006-07-17 Revised:2006-09-29 Published:2007-02-01
  • Contact: GENG Zhi-Yuan E-mail:zhiyuangeng@yahoo.com.cn

摘要: 采用二阶微扰理论的MP2/6-31G(d,p)方法对气相中烯丙基负离子与N2O的反应机理进行了理论计算研究, 并在相同基组下进一步用CCSD(T)方法进行了单点能的校正. 计算结果表明, 该反应存在三条反应通道, 产物分别为cis-CH2CHCNN-+H2O, trans-CH2CHCNN-+H2O和CH2CCH-+N2+H2O, 其中生成cis-CH2CHCNN-和trans-CH2CHCNN-的两条通道为相互竞争的主反应通道, 计算结果与实验相吻合. 同时利用传统的过渡态理论, 计算了各反应通道在298 K时, 速控步骤的反应速率常数k(T).

关键词: 烯丙基负离子, 反应机理, 二阶微扰理论(MP2), 过渡态理论

Abstract: The gas-phase reaction mechanism of allyl anion with N2O was investigated at the MP2/6-31G(d,p) level of the MP2 theory. The single-point energies have also been refined at the CCSD(T)/6-31G(d,p) level to get more accurate energies using the MP2/6-31G(d,p) optimized geometries. The computational results indicated that the reaction involved three reaction pathways to produce cis-vinyl-diazomethyl anion, trans-vinyl-diazomethyl anion, and allenyl anion. The major competition channels of the reaction which produced cis-vinyl-diazomethyl anion, and trans-vinyl-diazomethyl anion all involved two steps of α-H migration. Furthermore, all these rate-determing steps are the second α-H migration and the barriers are 89.79 and 97.93 kJ·mol-1, respectively. Distinctly, allenyl anion was formed through one α-H and one β-H migration and its rate-determing step was the rotation of the N10—O11 and N9—C3 bonds around N—N bond. The rate coefficients of the rate-determining step of all the reaction channels have also been calculated using statistic thermodynamics and conventional transition state theory at 298 K.

Key words: Allyl anion, reaction mechanism, Second-order Moller-Plesset perturbation theory (MP2), Transition state theory