Ab initio potential energy surface for the reaction of O(3P) with CH2F

The potential energy surface (PES) for the reaction of an oxygen atom with a fluorinated methyl radical has been studied using the G2MP2 level of theory. The calculations reveal an association–elimination mechanism. The addition reaction of O(3P) to CH2F produces an energy-rich intermediate OCH2F∗ which subsequently decomposes irreversibly. Five production channels of OCH2F∗ are found: H+CHFO, HF+HCO, CHFOH, F+CH2O and H2+FCO. CHFOH can decompose through six production channels: H+CHFO, HF+HCO, H+HCOF, H2+FCO, F+HCOH and OH+CHF. Based on the present ab initio PES, the kinetic characteristics of the O(3P)+CH2F reaction are estimated. The energy-specific rate constants for the unimolecular decomposition of OCH2F are calculated by RRKM theory. H+CHFO are predicted to be the major products.