Skip to content
Journal article

Peroxy radical chemistry and OH radical production during the NO3-initiated oxidation of isoprene

Kwan A, H. C, Ng N, Kjaergaard H, Seinfeld J, Wennberg P...(+6 more)

Atmos. Chem. Phys., vol. 12 (2012) pp. 7499-7515

  • 2

    Readers

    Mendeley users who have this article in their library.
  • N/A

    Citations

    Citations of this article.
  • N/A

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

Peroxy radical reactions (RO2 + RO2 ) from the NO3 -initiated oxidation
of isoprene are studied with both gas chromatography and a chemical
ionization mass spectrometry technique that allows for more specific
speciation of products than in previous studies of this system. We
find high nitrate yields (∼ 80 %), consistent with other studies.
We further see evidence of significant hydroxyl radical (OH)formation
in this system, which we propose comes from RO2 + HO2 reactions with
a yield of ∼ 38–58 %. An additional OH source is the second generation
oxidation of the nitrooxyhydroperoxide, which produces OH and a dinitrooxyepoxide
with a yield of ∼ 35 %. The branching ratio of the radical propagating,
carbonyl- and alcohol-forming, and organic peroxide-forming channels
of the RO2 + RO2 reaction are found to be ∼ 18–38 %, ∼ 59–77 %, and
∼ 3–4 %, respectively. HO2 formation in this system is lower than
has been previously assumed. Addition of RO2 to isoprene is suggested
as a possible route to the formation of several isoprene C10 -organic
peroxide compounds (ROOR). The nitrooxy, allylic, and C5 peroxy radicals
present in this system exhibit different behavior than the limited
suite of peroxy radicals that have been studied to date.

Cite this document

Choose a citation style from the tabs below