Ab initio study of intramolecular hydrogen transfer in formylperoxy radical

Ab initio calculations on the structures and energies of the intramolecular hydrogen transfer of formylperoxy radical (HC(O)OO) has been performed. There are two isomeric forms (Z and E) of this structure and a total of six possible paths for carrying out the intramolecular hydrogen transfer. The transition-state structures were analyzed and the energy barriers calculated at several high levels of calculations, including G2MP2. The products associated with different paths of intramolecular hydrogen transfer were also located, among which the product channel, HO2 + CO, was calculated to have the lowest energy barrier. This product channel was also frequently observed in the HCO + O2 experimental reaction. The calculated energy barrier was less than 34 kcal/mol (G2) and dependent on the isomeric form. The potential energy profile for all six possible paths was presented.