Liang YN, Li J, Wang QD, Wang F, Li XY. Computational study of the reaction mechanism of the methylperoxy self-reaction.
J Phys Chem A 2011;
115:13534-41. [PMID:
22004094 DOI:
10.1021/jp2048508]
[Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To provide insight on the reaction mechanism of the methyperoxy (CH(3)O(2)•) self-reaction, stationary points on both the spin-singlet and the spin-triplet potential energy surfaces of 2(CH(3)O(2)•) have been searched at the B3LYP/6-311++G(2df,2p) level. The relative energies, enthalpies, and free energies of these stationary points are calculated using CCSD(T)/cc-pVTZ. Our theoretical results indicate that reactions on a spin-triplet potential energy surface are kinetically unfavorable due to high free energy barriers, while they are more complicated on the spin-singlet surface. CH(3)OOCH(3) + O(2)(1) can be produced directly from 2(CH(3)O(2)•), while in other channels, three spin-singlet chain-structure intermediates are first formed and subsequently dissociated to produce different products. Besides the dominant channels producing 2CH(3)O• + O(2) and CH(3)OH + CH(2)O + O(2) as determined before, the channels leading to CH(3)OOOH + CH(2)O and CH(3)O• + CH(2)O + HO(2)• are also energetically favorable in the self-reaction of CH(3)O(2)• especially at low temperature according to our results.
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