Accurate ab initio calculations on the rate constants of the hydrogen abstraction reaction C2H3+H2→H+C2H4

Abstract The hydrogen abstraction reaction C 2 H 3 +H 2 →C 2 H 4 +H has been studied using direct ab initio dynamics method in the temperature range 298–3000 K. All of the information along the minimum energy path (MEP) was calculated at the MP4(SDQ)/6-311++G(d, p) level of theory. In order to obtain more reliable energies, energetic data along the MEP were further refined using the G2 scheme. The barrier heights for the forward and reverse reactions were obtained as 9.95 and 16.07 kcal mol −1 , respectively. Reaction rate constants and activation energies were calculated for the temperature range 298–3000 K using the improved canonical variation transition state theory incorporating a small-curvature tunneling correction. The results of theoretical reaction rate constants and the activation energies are in good agreement with experimental data over the measured temperature range of 298–947 K.

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