Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (10): 2619-2624.doi: 10.3866/PKU.WHXB20100938

• CHEMICAL KINETICS AND MOLECULE DYNAMICS • Previous Articles     Next Articles

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).

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