Title: | Watching a hydroperoxyalkyl radical (*QOOH) dissociate |
Author(s): | Hansen AS; Bhagde T; Moore KB; Moberg DR; Jasper AW; Georgievskii Y; Vansco MF; Klippenstein SJ; Lester MI; |
Address: | "Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA. Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA. Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA. sjk@anl.gov milester@sas.upenn.edu. Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA. sjk@anl.gov milester@sas.upenn.edu" |
ISSN/ISBN: | 1095-9203 (Electronic) 0036-8075 (Linking) |
Abstract: | "A prototypical hydroperoxyalkyl radical (*QOOH) intermediate, transiently formed in the oxidation of volatile organic compounds, was directly observed through its infrared fingerprint and energy-dependent unimolecular decay to hydroxyl radical and cyclic ether products. Direct time-domain measurements of *QOOH unimolecular dissociation rates over a wide range of energies were found to be in accord with those predicted theoretically using state-of-the-art electronic structure characterizations of the transition state barrier region. Unimolecular decay was enhanced by substantial heavy-atom tunneling involving O-O elongation and C-C-O angle contraction along the reaction pathway. Master equation modeling yielded a fully a priori prediction of the pressure-dependent thermal unimolecular dissociation rates for the *QOOH intermediate-again increased by heavy-atom tunneling-which are required for global models of atmospheric and combustion chemistry" |
Notes: | "PubMed-not-MEDLINEHansen, Anne S Bhagde, Trisha Moore, Kevin B 3rd Moberg, Daniel R Jasper, Ahren W Georgievskii, Yuri Vansco, Michael F Klippenstein, Stephen J Lester, Marsha I eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2021/08/07 Science. 2021 Aug 6; 373(6555):679-682. doi: 10.1126/science.abj0412" |