The gas‐phase ozonolysis reaction of methylbutenol: A mechanistic study

AbstractThe gas‐phase ozonolysis reaction of methylbutenol through the Criegee mechanism is investigated. The initial reaction leads to a primary ozonide (POZ) formation with barriers in the range of 10–28 kJ mol−1. The formation of 2‐hydroxy‐2‐methyl‐propanal (HMP) and formaldehyde‐oxide is more favorable, by 10 kJ mol−1, than the syn‐CI and formaldehyde. The unimolecular dissociation of the more stable syn‐CI via 1,5‐H transfer into an epoxide is more favored than the epoxide and 3O2 formation. The ester channel led to the formation of the acetone and formic acid favorably from the anti‐CI. The hydration of the anti‐CI with H2O and (H2O)2 is significantly barrierless with a higher plausibility to the latter, and thus they may lead to the formation of peroxides and ultimately OH radicals, as well as airborne particulate matter. Reaction of anti‐CI with water dimers enhances its atmospheric reactivity by a factor of 28 in reference to water monomers.