Investigation of the atmospheric oxidation pathways of bromoform and dibromomethane: Initiation via UV photolysis and hydrogen abstraction Academic Article

abstract

• A computational study of the oxidation of CH 2Br 2 and CHBr 3 initiated via both UV photolysis and abstraction of an H atom by OH/Cl radicals has been performed. We have calculated the energetics associated with the addition of O 2 to the substituted bromomethyl radicals and the subsequent addition of NO to the peroxy radicals to form energized peroxy nitrite molecules. The peroxy nitrite molecules are predicted to dissociate rapidly to form alkoxy radicals (CH 2BrO and CHBr 2O) and NO 2, and the kinetics of these reactions have been determined using Rice-Ramsperger-Kassel-Marcus/master equation calculations. We additionally find that the reaction of the peroxy radicals with HO 2 may directly lead to significant production of alkoxy radicals, a pathway that is unimportant in nonbrominated analogues. We predict that the alkoxy radicals will dissociate rapidly via C-Br bond cleavage. The atmospheric implications of these results will be discussed.

authors

• North, Simon

published proceedings

• JOURNAL OF PHYSICAL CHEMISTRY A

author list (cited authors)

• McGivern, W. S., Kim, H. J., Francisco, J. S., & North, S. W.

citation count

• 25

complete list of authors

• McGivern, WS||Kim, HJ||Francisco, JS||North, SW

publication date

• September 2004

publisher

• American Chemical Society (ACS)  Publisher

published in

• The Journal of Physical Chemistry A: Isolated Molecules, Clusters, Radicals, and Ions; Environmental Chemistry, Geochemistry, and Astrochemistry; Theory  Journal

keywords

• 34 Chemical Sciences
• 3406 Physical Chemistry
• 3407 Theoretical And Computational Chemistry

Digital Object Identifier (DOI)

• 10.1021/jp0311613

start page

• 7247

end page

• 7252

volume

• 108

issue

• 35

URL

• http://dx.doi.org/10.1021/jp0311613