The Reactions of Sulfuric Acid with Biogenic Criegee Intermediates or Secondary Ozonides as a Possible Source of Nucleation Precursors
We have studied the reactions of sulfuric acid with stabilized Criegee Intermediates (sCIs) and secondary ozonides formed in the ozonolysis of biogenic mono- and sesquiterpenes. Activation energy calculations on model species show that the reaction between sulfuric acid and sCIs is almost barrierless. If the lifetime of biogenic sCIs in the atmosphere is sufficiently long for them to undergo bimolecular reactions, then the sCI plus sulfuric acid reaction could account some part of the organically assisted new-particle formation events observed in the atmosphere. If, on the other hand, unimolecular formation of secondary ozonides is the main sink reaction of sCIs, then the reactions between sulfuric acid and the secondary ozonides could be of atmospheric importance. For the secondary ozonide formed from a-pinene, we have found a strongly exothermic reaction which results in the formation of a sulfuric acid monoester plus a water molecule. However, this reaction may have high activation energy.
Keywords Nucleation, sulfuric acid, Criegee intermediate, secondary ozonide, quantum chemistry
KeywordsSulfuric Acid Bimolecular Reaction Standard Gibbs Free Energy Sulfuric Acid Ester Activation Energy Calculation
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