Title: | Direct Observation of Aliphatic Peroxy Radical Autoxidation and Water Effects: An Experimental and Theoretical Study |
Address: | "IRCELYON, CNRS, Universite Claude Bernard Lyon 1, 2 avenue Albert Einstein, 69626, Villeurbanne, France. Forschungszentrum Julich GmbH, 52425, Julich, Germany" |
ISSN/ISBN: | 1521-3773 (Electronic) 1433-7851 (Linking) |
Abstract: | "The autoxidation of organic peroxy radicals (RO(2) ) into hydroperoxy-alkyl radicals (QOOH), then hydroperoxy-peroxy radicals (HOOQO(2) ) is now considered to be important in the Earth's atmosphere. To avoid mechanistic uncertainties these reactions are best studied by monitoring the radicals. But for the volatile and aliphatic RO(2) radicals playing key roles in the atmosphere this has long been an instrumental challenge. This work reports the first study of the autoxidation of aliphatic RO(2) radicals and is based on monitoring RO(2) and HOOQO(2) radicals. The rate coefficients, k(iso) (s(-1) ), were determined both experimentally and theoretically using MC-TST kinetic theory based on CCSD(T)//M06-2X quantum chemical methodologies. The results were in excellent agreement and confirmed that the first H-migration is strongly rate-limiting in the oxidation of non-oxygenated volatile organic compounds (VOCs). At higher relative humidity (2-30 %) water complexes were evidenced for HOOQO(2) radicals, which could be an important fate for HOO-substituted RO(2) radicals in the atmosphere" |
Keywords: | atmospheric chemistry autoxidation mass spectrometry peroxy radicals water complexation; |
Notes: | "PubMed-not-MEDLINENoziere, Barbara Vereecken, Luc eng NSF-ATM0232057/National Science Foundation/ Review Germany 2019/07/31 Angew Chem Int Ed Engl. 2019 Sep 23; 58(39):13976-13982. doi: 10.1002/anie.201907981. Epub 2019 Aug 21" |