Unimolecular reactions of protonated hydrogen peroxide: A quantum chemicalsurvey

The unimolecular chemistry of the system [HOOH]H+ has been investigated usi ng ab initio quantum chemical methods. In analogy with the isoelectronic sy stems-[H2NNH2]H+ and [HONH2]H+, in this paper subject to more detailed stud ies than previously-the lowest energy pathway for decomposition of protonat ed hydrogen peroxide is loss of an oxygen atom in its triplet electronic st ate, giving H3O+ as the ionic product. This process requires a crossover fr om the singlet to the triplet potential energy surface, and the minimum ene rgy crossing point was located. The proton affinity was also calculated and found to be in good accordance with one experimental determination.