Laboratory kinetics of C2H radical reactions with ethane, propane and n-butane at T = 96-296 K: Implicatiions for Titan

Published

May 1, 2003

Author(s)

J E. Murphy, A B. Vakhtin, S R. Leone

Abstract

The kinetics of the reactions of C₂H radical with ethane (K₁), propane (k₂), and n-butane (k₃) are studied over the temperature range of T=96-296 K with a pulsed Laval nozzle apparatus that utilizes a pulsed laser photolysis/chemiluminescence technique. The C₂H decay profiles in the presence of both the alkane reactant and O₂ are monitored by the CH(A²Δ}) chemiluminescence tracer method. The results, together with available literature data, yield the following Arrhenius expressions: k₁(T) = (0.51 ± 0.06) x 10^-10 exp [(-76 ± 30) K/T] cm³ molecule^-1s^-1 (T = 96 K to 800 K), k₂(T) = (0.98 ± 0.32) x 10^-10 exp[(-71 + or-} 60) K/T] cm³ molecule^-1s^-1 (T = 96 K to 361 K), and k₃(T) = (1.23 ± 0.26) x 10^-10 cm³ molecule^-1s^-1 (T = 96 K to 297 K). At T = 296 K, k₁ is measured as a function of total pressure and has little or no pressure dependence. The results from this work support a direct hydrogen abstraction mechanism for the title reactions. Implications to the atmospheric chemistry of Titan are discussed.

Citation

Icarus

Volume

163

Issue

No. 1

Pub Type

Journals

Keywords

C₂H radical reactions, stratopheric mixing, Titan

Citation

Murphy, J. , Vakhtin, A. and Leone, S. (2003), Laboratory kinetics of C₂H radical reactions with ethane, propane and n-butane at T = 96-296 K: Implicatiions for Titan, Icarus (Accessed July 26, 2024)