物理化学学报 >> 2013, Vol. 29 >> Issue (04): 683-688.doi: 10.3866/PKU.WHXB201302046

热力学,动力学和结构化学 上一篇    下一篇

C2(X1Σg+)自由基与不饱和碳氢化合物反应的温度效应

胡仁志1, 谢品华1, 张群2, 司福祺1, 陈旸2   

  1. 1 中国科学院安徽光学精密机械研究所, 中国科学院环境光学与技术重点实验室, 合肥 230031;
    2 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:2012-11-30 修回日期:2013-01-30 发布日期:2013-03-25
  • 通讯作者: 胡仁志, 陈旸 E-mail:hurz@mail.ustc.edu.cn; yangchen@ustc.edu.cn
  • 基金资助:

    国家自然科学基金(61108031, 21173205); 国家重点基础研究发展规划项目(973) (2010CB923302)及中国科学院知识创新工程(KJCX2-YW-N24)资助

Temperature Dependence of C2(X1Σg+) in Reactions with Unsaturated Hydrocarbons

HU Ren-Zhi1, XIE Pin-Hua1, ZHANG Qun2, SI Fu-Qi1, CHEN Yang2   

  1. 1 Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Science, Hefei 230031, P. R. China;
    2 Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
  • Received:2012-11-30 Revised:2013-01-30 Published:2013-03-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (61108031, 21173205), National Key Basic Research Program of China (973) (2010CB923302), and Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering, China (KJCX2-YW-N24).

摘要:

运用脉冲激光光解-激光诱导荧光(PLP-LIF)的方法在293-573 K的温度范围内测量了C2(X1Σg+)自由基与不饱和碳氢化合物(C2H4和C2H2)气相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(单位: cm3·molecule-1·s-1): k(C2H4)=(1.16±0.10)×10-10exp[(290.68±9.72)/T], k(C2H2)=(1.36±0.02)×10-10exp[(263.85±7.60)/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, 我们认为在293-573 K温度范围内C2(X1Σg+)自由基和不饱和碳氢化合物的反应遵循加成机理.

关键词: C2(X1Σg+)自由基, 激光诱导荧光, 速率常数, 温度效应

Abstract:

Bimolecular rate constants for the gas-phase reactions of C2(X1Σg+) with unsaturated hydrocarbons C2H4 and C2H2 were measured over the temperature range 293-573 K by pulsed laser photolysis/laserinduced fluorescence (PLP-LIF). The rate constants, in the unit of cm3·molecule-1·s-1, can be fitted by the normal Arrhenius expressions: k(C2H4)=(1.16±0.10)×10-10exp[(290.68±9.72)/T], and k(C2H2)=(1.36±0.02)×10-10exp[(263.85 ± 7.60)/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 conclude that the reactions of C2(X1Σg+) with these unsaturated hydrocarbons in the temperature range 293- 573 K proceed via an addition mechanism.

Key words: C2(X1Σg+) radical, Laser induced fluorescence, Rate constant, Temperature dependence

MSC2000: 

  • O643