Role of Hydrogen Migrations in Carbonyl Peroxy Radicals in the Atmosphere

Carbonyl peroxy radicals (RC(O)O₂) are the ubiquitous radical intermediates in the atmospheric oxidation of volatile organic compounds. In this work, theoretical studies are carried out to explore the role of the unimolecular H-migration in the carbonyl peroxy radicals by using quantum chemistry and kinetics calculations. The results showed that H-migration could be significant in the atmosphere at least in CH₃CH₂CH₂C(O)O₂ and (CH₃)₂CHCH₂C(O)O₂ with rates of ∽0.012 and ∽0.58 s^?1 at 298 K. Subsequent reactions of CH₃CHCH₂C(O)OOH would lead to the products with multi-functional groups, which might affect the aerosol formation process; while (CH₃)₂CCH₂C(O)OOH would transform to formaldehyde and acetone in a few steps. These processes would be important for the atmospheric modelling of volatileorganic compounds under low-NO_x conditions.