物理化学学报 >> 2010, Vol. 26 >> Issue (10): 2619-2624.doi: 10.3866/PKU.WHXB20100938

化学动力学和分子动态学 上一篇    下一篇

C2(a3Πu)自由基与若干不饱和碳氢化合物反应的温度效应

胡仁志, 张群, 陈旸   

  1. 中国科学技术大学化学物理系,合肥微尺度物质科学国家实验室, 合肥230026
  • 收稿日期:2010-04-07 修回日期:2010-05-07 发布日期:2010-09-27
  • 通讯作者: 张群, 陈旸 E-mail:qunzh@ustc.edu.cn, yangchen@ustc.edu.cn
  • 基金资助:

    国家自然科学基金(20673107, 20873133), 国家重点基础研究发展规划项目(973)(2007CB815203, 2010CB923302)及中国科学院知识创新工程(KJCX2-YW-N24)资助

Temperature Dependence of Reactions of C2(a3Πu) Radical with Several Unsaturated Hydrocarbons

HU Ren-Zhi, ZHANG Qun, CHEN Yang   

  1. Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science andTechnology of China, Hefei 230026, P. R. China
  • Received:2010-04-07 Revised:2010-05-07 Published:2010-09-27
  • Contact: ZHANG Qun, CHEN Yang E-mail:qunzh@ustc.edu.cn, yangchen@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20673107, 20873133), National Key Basic Research Programof China (973) (2007CB815203, 2010CB923302), and Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering (KJCX2-YW-N24).

摘要:

运用脉冲激光光解-激光诱导荧光(PLP -LIF) 的方法研究了C2(a3Πu)自由基与若干不饱和碳氢化合物(C2H4 (k1),C2H2 (k2),C3H6 (k3)和2-C4H8 (k4))气相反应的温度效应. 在298-673K 的温度范围内, 获得了这些反应的双分子反应速率常数. 获得的速率常数可以用Arrhenius 公式表达如下: k1(T)=(4.53 ±0.05) ×10-11exp[(196.41 ±5.20)/T], k2(T)=(3.94 ±0.04) ×10-11exp[(143.04 ±4.28)/T], k3(T)=(7.96 ±0.17) ×10-11exp[(185.10 ±8.86)/T], k4(T)=(1.04 ±0.02) ×10-10 exp[(180.34 ±7.67)/T], 误差为±2σ. 由获得的双分子反应速率常数及其所呈现的负温度效应, 在298-673K 温度范围内,C2(a3Πu)自由基和这些不饱和碳氢化合物的反应遵循加成机理.

 

关键词: C2(a3Πu)自由基, 激光诱导荧光, 速率常数, 温度效应

Abstract:

We studied the temperature dependence on the gas phase reactions of theC2(a3Πu) radical with several unsaturated hydrocarbons (C2H4 (k1),C2H2 (k2),C3H6 (k3), and 2-C4H8 (k4)) by means of pulsed laser photolysis-laser induced fluorescence (PLP-LIF) technique. The bimolecular rate constants for these reactions were obtained in the temperature range of 298-673 K. The obtained kinetics data were used to derive the following Arrhenius expressions: k1(T)=(4.53 ±0.05) ×10-11exp[(196.41 ±5.20)/T], k2(T)=(3.94 ±0.04) ×10-11exp[(143.04 ±4.28)/T], k3(T)=(7.96 ±0.17) ×10-11 exp[(185.10 ±8.86)/T], and k4(T)=(1.04 ±0.02) ×10-10exp[(180.34 ±7.67)/T], where all error estimates are ±2σ and represent the precision of the fit. The observed bimolecular rate constants along with the negative temperature dependences of k(T) allow us to reacha conclusion that the reactions of C2(a3Πu) with these unsaturated hydrocarbons in the temperature range of 298-673 K proceed via an addition mechanism.

 

Key words: C2(a3Πu) radical, Laser induced fluorescence, Rate constant, Temperature dependence

MSC2000: 

  • O643