A computational study of the reactions of atomic hydrogen with fluoromethanes: kinetics and product channels

Transition states for the H-abstraction, F-abstraction and substitution pathways of the reaction of H with fluoromethanes were characterized at the HF and MP2(FU) levels of theory with the 6–31G(d) basis set. The reaction barrier heights for these pathways were obtained from single point energy calculations using the Gaussian-2 and BAC-MP4 methods. These results were employed to calculate rate constants via transition state theory. The computed rate constants are in good accord with available experimental data, and are discussed in the context of the differing flame suppression chemistries of CH3F, CH2F2, CHF3 and CF4.