Product Vibrational State Distributions of F+CH₃OH Reaction on Full-Dimensional Accurate Potential Energy Surface

The hydrogen abstraction reaction of methanol with fluorine atoms can produce HF and CH _3 O or CH _2 OH radicals, which are important in the environment, combustion, radiation, and interstellar chemistry. In this work, the dynamics of this typical reaction is investigated by the quasi-classical trajectory method based on a recently developed globally accurate full-dimensional potential energy surface. Particularly, the vibrational state distributions of the polyatomic products CH _3 O and CH _2 OH are determined by using the normal mode analysis method. It is found that CH _3 O and CH _2 OH are dominantly populated in the ground state when the reactants are at the ground ro-vibrational state. The OH stretching mode, torsional mode, H _2 CO out-of-plane bending mode and their combination bands in the CH _2 OH product can be effectively excited once the OH stretching mode of the reactant CH _3 OH is excited to the first vibrationally excited state. Most of the available energy flows into the HF vibrational energy and the translational energy in both channels, while the radical products, CH _3 O or CH _2 OH, receive a small amount of energy, consistent with experiment, which is an indication of its spectator nature.