Theoretical characterization of the reaction of hydroperoxy with formaldehyde

The reaction of HO 2 +formaldehyde is characterized at both the semiempirical and ab initio levels. It is shown that semiempirical methods do not furnish the information necessary to rationalize the kinetics of the formation of OOCH 2 OH. The mechanism of this reaction is rationalized at both the MP4/6-31G ** and BAC MP4/6-31G ** levels. The critical transition state for this reaction involves the simultaneous addition of the terminal oxygen atom of HO 2 to the carbon of the CO bond and transfer of a proton from OOH to the oxygen of this same bond. It is shown that the previously proposed mechanism involving the intermediate formation of the HOOCH 2 O radical is incorrect