Is either direct photolysis or photocatalysed H-shift of peroxyl radicals a competitive pathway in the troposphere?

ABSTRACT: Peroxyl radicals (RO O . ) are key intermediates in atmospheric chemistry, with relatively long lifetimes compared to most other radical species. In this study, we use multireference quantum chemical methods to investigate whether photolysis can compete with well-established RO O . sink reactions. We assume that the photolysis channel is always RO O . + hν => RO + O(³P). Our results show that the maximal value of the cross-section for this channel is σ = 1.3 × 10^-18 cm² at 240 nm for five atmospherically representative peroxyl radicals: CH₃O O . , C(O)HCH₂O O . , CH₃CH₂O O . , HC(O)O O . and CH₃C(O)O O . . These values agree with experiments to within a factor of 2.

SUBMITTER: Valiev RR 

PROVIDER: S-EPMC7540759 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature