Reaction mechanism duality in O(1D2) + CD4→ OD + CD3 identified from scattering distributions of rotationally state selected CD3

Abstract

The scattering distributions of rotationally state-selected CD₃ products in the O(¹D₂) reaction with deuterated methane at a collision energy of 5.6 kcal/mol were investigated. Markedly different features were found between the forward and backward scatterings of rovibrationally unexcited CD₃, which provides the experimental evidence of the dual reaction mechanisms, i.e., insertion and abstraction on the ground- and excited-state potential energy surfaces, respectively, in this benchmark system. The gradual emergence of forward-backward symmetry in the angular distributions of CD₃ in higher rotational states suggests that osculating complexes create rotationally hotter CD₃.