Isoprene NO3 Oxidation Products from the RO2 + HO2 Pathway.

Autor:	Schwantes RH; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Teng AP; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Nguyen TB; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Coggon MM; Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Crounse JD; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., St Clair JM; Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center , Greenbelt, Maryland 20771, United States.; Joint Center for Earth Systems Technology, University of Maryland Baltimore County , Baltimore, Maryland 21250, United States., Zhang X; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Schilling KA; Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Seinfeld JH; Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.; Division of Engineering and Applied Science, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States., Wennberg PO; Division of Geological and Planetary Sciences, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.; Division of Engineering and Applied Science, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.
Jazyk:	angličtina
Zdroj:	The journal of physical chemistry. A [J Phys Chem A] 2015 Oct 08; Vol. 119 (40), pp. 10158-71. Date of Electronic Publication: 2015 Sep 24.
DOI:	10.1021/acs.jpca.5b06355
Abstrakt:	We describe the products of the reaction of the hydroperoxy radical (HO(2)) with the alkylperoxy radical formed following addition of the nitrate radical (NO(3)) and O(2) to isoprene. NO(3) adds preferentially to the C(1) position of isoprene (>6 times more favorably than addition to C(4)), followed by the addition of O(2) to produce a suite of nitrooxy alkylperoxy radicals (RO(2)). At an RO(2) lifetime of ∼30 s, δ-nitrooxy and β-nitrooxy alkylperoxy radicals are present in similar amounts. Gas-phase product yields from the RO(2) + HO(2) pathway are identified as 0.75-0.78 isoprene nitrooxy hydroperoxide (INP), 0.22 methyl vinyl ketone (MVK) + formaldehyde (CH(2)O) + hydroxyl radical (OH) + nitrogen dioxide (NO(2)), and 0-0.03 methacrolein (MACR) + CH(2)O + OH + NO(2). We further examined the photochemistry of INP and identified propanone nitrate (PROPNN) and isoprene nitrooxy hydroxyepoxide (INHE) as the main products. INHE undergoes similar heterogeneous chemistry as isoprene dihydroxy epoxide (IEPOX), likely contributing to atmospheric secondary organic aerosol formation.
Databáze:	MEDLINE
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