Theoretical study of the H-abstraction reaction of the CH3O radical with formaldehyde

The purpose of the present Letter is to investigate the mechanism of the bimolecular abstraction reaction of the methoxy radical (CH3O) with formaldehyde and to compute gas-phase thermal rate constants using conventional transition state theory including tunneling corrections. The potential information needed to calculate the rate constants is obtained from ab initio electronic structure calculations. We report the ab initio UHF, MP2, MP4, CASSCF, CASPT2 and MRCI results obtained by using ANO basis sets as well as HF-DFT (B3LYP) results obtained by using the 6-311++G** basis set. The theoretical rate constants obtained from the MRSDCI potential are in good agreement with the experimental values.