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| Titel |
Photolysis and OH reactivity of a Proxy for Isoprene-derived Hydroperoxyenals |
| VerfasserIn |
G. M. Wolfe, J. D. Crounse, J. Parrish, J. M. St. Clair, T. Yoon, P. O. Wennberg, F. N. Keutsch |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058795
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| Zusammenfassung |
| In isoprene-dominated regions, classical chemical mechanisms routinely under-predict the
observed abundance and partitioning of hydrogen oxide radicals (HOx = OH +
HO2). Recently-proposed mechanisms for the regeneration of HOx during isoprene
oxidation have demonstrated promise in chemical models; however, many of these
theorized reactions remain untested in the laboratory. One such chemical scheme,
commonly known as the Leuven mechanism, permits efficient OH recycling in low-NO
environments via isomerization and decomposition of first-generation isoprene
hydroxyperoxyl radicals. The hydroperoxyenal (HPALD) products of this chemistry are
proposed to play a crucial role, as their photolysis and subsequent degradation may
provide a heretofore unrecognized primary source of OH and HO2 radicals. Using a
custom-synthesized proxy molecule, we have conducted a series of laboratory chamber
studies to characterize the unique chemistry of these putative HPALD compounds.
Specific experiments were designed to assess 1) the photolysis quantum yield, 2) the
photolysis OH yield, and 3) the rate and branching of reaction with OH. Key results will
be compared with predictions for the isoprene-derived HPALD and placed in the
context of our current understanding of OH recycling in high VOC environments. |
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