Study on Anharmonic Effect of the Unimolecular Reaction of CH₂(D₂)FO

Study on the unimolecular reaction for CH₂FO and CD₂FO is carried out. The structures, energy barriers and zero point energy of the three channels in the title unimolecular reactions are computed with the MP2/6- 311++G(3df, 3pd) method. RRKM theory is used to calculate the rate constants of canonical case at temperature range of 500-5000 K and microcanonical system at total energy of 19.05-71.68 kcal/mol. The results indicate that the anharmonic effect and isotope effect are very small for the three channels, and the anharmonic rate constants, around 10''9 -10''11 s''-1 , are close to the experimental prediction reasonably