Solving the discrepancy between the direct and relative-rate determinations of unimolecular reaction kinetics of dimethyl-substituted Criegee intermediate (CH3)2COO using a new photolytic precursor

文献情報

出版日 2022-01-26

DOI 10.1039/D1CP02270A

インパクトファクター 3.676

著者

Jari Peltola, Prasenjit Seal, Niko Vuorio, Petri Heinonen, Arkke Eskola

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要旨

We have performed direct kinetic measurements of the thermal unimolecular reaction of (CH3)2COO in the temperature range 243–340 K and pressure range 5–350 Torr using time-resolved UV-absorption spectroscopy. We have utilized a new photolytic precursor, 2-bromo-2-iodopropane ((CH3)2CIBr), which photolysis at 213 nm in the presence of O2 produces acetone oxide, (CH3)2COO. The results show that the thermal unimolecular reaction is even more important main loss process of (CH3)2COO in the atmosphere than direct kinetic studies have suggested hitherto. The current experiments show that the unimolecular reaction rate of (CH3)2COO at 296 K and atmospheric pressure is 899 ± 42 s−1. Probably more importantly, current measurements bring the direct and relative-rate measurements of thermal unimolecular reaction kinetics of (CH3)2COO into quantitative agreement.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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