Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (04): 683-688.doi: 10.3866/PKU.WHXB201302046


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).


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