The dynamics of reactions of O(3P) atoms with allene and methylacetylene

The reactions of O(³P) atoms with allene and methylacetylene: O+CH₂=C=CH₂

CO+C₂H₄,ΔH₁⁰ = ?119.4 kcal/mole, O+CH₃-C

CH

CO+C₂H₄,ΔH₂⁰ = ?117.8 kcal/mole were studied at 293 K with a CO laser resonant absorption and a discharge-flow GC-sampling method. The CO formed in reaction (1) was found to have a vibrational temperature of 5100 ± 100 K, compared with 2400 ± 200 K in (2). The good agreement between the observed CO vibrational distributions and those predicted by simple statistical models indicates that the reaction energies were completely randomized.The present results also showed unambiguously that CH₃CH, instead of C₂H₄, was produced initially in reaction (2).