Kinetics and mechanism of the Glyoxal HO2 reaction: Conversion of HO2 to OH by carbonyls

Abstract

The kinetics of the glyoxal + HO2 reaction have been investigated using computational chemistry and statistical reaction rate theory techniques, with consideration of a novel pathway that results in the conversion of HO2 to OH. Glyoxal is shown to react with HO2 to form an α-hydroxyperoxy radical with additional α-carbonyl functionality. Intramolecular H atom abstraction from the carbonyl moiety proceeds with a relatively low barrier, facilitating decomposition to OH + CO + HC(O)OH (formic acid). Time-dependent master equation simulations demonstrate that direct reaction to form OH is relatively slow at ambient temperature. The major reaction product is predicted to be collisionally deactiva..