Atmospheric chemistry of olefins: a product study of the ozone-alkene reaction with cyclohexane added to scavenge hydroxyl radical

Abstract

Carbonyl and carboxylic acid products of the ozone-olefin reaction, in which the hydroxyl radical is produced, have been identified and measured for eight alkenes in the presence of excess cyclohexane, i.e., ruder conditions that minimize subsequent reactions of OH with the alkenes and with their carbonyl product. The carbonyls expected to form directly, i.e., alkene+ozone→1,d,3-trioxolane adduct→two carbonyls+two Criegee biradicals, were observed as major product (e.g., formaldehyde and d-butanone from d-methyl-1-butene). Their yields ranged from 9±2% for 1,3-butadiene to 88±4% for 2,3-dimethyl-d-butene. For alkenes that lead to two Criegee biradicals, carbonyl yields were consistent with preferential formation of the more substituted biradical