Open AccessProduct analysis of the OH oxidation of isoprene and 1,3‐butadiene in the presence of NO
Author(s) -
Sprengnether Michele,
Demerjian Kenneth L.,
Donahue Neil M.,
Anderson James G.
Publication year - 2002
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jd000716
Subject(s) - isoprene , furan , alkene , chemistry , radical , 1,3 butadiene , photochemistry , infrared spectroscopy , spectroscopy , infrared , organic chemistry , catalysis , polymer , physics , quantum mechanics , optics , copolymer
The oxidation mechanisms of isoprene and butadiene initiated by OH in the presence of NO have been explored under “wall‐less” flowing conditions, with products observed a few seconds after reaction by infrared spectroscopy. Since only ∼1% of alkene is reacted, any secondary chemistry is negligible. The use of reaction modulation spectroscopy permits the accurate measurement of a percent change in high alkene concentration and of 10 13 molecules/cm 3 concentrations for products. Measured carbonyl species agree with previous studies, while alkyl nitrate yields are consistent with upper values reported in the literature. NO sensitivity studies performed exclude the possibility of competing chemistry. Isoprene is not observed to form 3‐methyl furan, indicating that this is not a prompt oxidation product. However, butadiene does form furan. In an auxiliary experiment, peroxy radicals in the second stage of butadiene oxidation are fully converted to peroxynitrates. Average cross sections for integrated peroxynitrate bands are determined from this experiment.