The bimolecular hydrogen abstraction reactions of methane with atoms have become benchmark systems to test and extend our knowledge of polyatomic chemical reactivity. We review the state-of-the-art methodologies for reaction dynamics computations of X + methane [X = F, O(3P), Cl, Br] reactions, which consist of two key steps: (1) potential energy surface (PES) developments and (2) reaction dynamics computations on the PES using either classical or quantum methods. We briefly describe the permutationally invariant polynomial approach for step 1 and the quasiclassical trajectory method, focusing on the mode-specific polyatomic product analysis and the Gaussian binning (1GB) techniques, and reduced-dimensional quantum models for step 2. High-quality full-dimensional ab initio PESs and dynamical studies of the X + CH4 and CHD3 reactions are reviewed. The computed integral cross-sections, angular, vibrational, and rotational product distributions are compared with available experiments. Both experimental and theoretical findings shed light on the rules of mode-selective polyatomic reactivity.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry