The reaction of OH radical with the Criegee intermediate propanone oxide: Theoretical investigations

Abstract

The mechanism and kinetics of reaction of the Criegee intermediate (CH3)2CO(O) with OH radicals is investigated by theoretical methods. The stationary point on the potential energy surface of the reaction and their corresponding molecular properties are calculated by quantum-chemical methods. The significant product channel is found to be CH3COCH3 + HO2 (P1). The product CH3CO(O)CH2 + H2O (P3) is also predicted to be formed effectively at low temperatures. The reaction path (CH3)2CO(O) + OH → CH3COCH2 + 2 OH which is an auto-catalytic pathway for degradation of the Criegee intermediate has been of special interest. The rate constants for all important product channels including the latter auto-catalytic pathway are computed by statistical rate theories. It is found that the latter auto-catalytic process is not of importance in the kinetics of the title reaction.