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Laser Flash Photolysis Studies of Radical-Radical Reaction Kinetics: The O((sup 3)P(sub J)) + BrO ReactionA novel dual laser flash photolysis-long path absorption-resonance fluorescence technique has been employed to study the kinetics of the important stratospheric reaction 0((sup 3)P(sub j)) + Br yields(k1) BrO((sup 2)P(sub J)) + O2 as a function of temperature (231-328 K) and pressure (25-150 Torr) in N2 buffer gas. The experimental approach preserves the principal advantages of the flash photolysis method, i.e., complete absence of surface reactions and a wide range of accessible pressures, but also employs techniques which are characteristic of the discharge flow method, namely chemical titration as a means for deducing the absolute concentration of a radical reactant and use of multiple detection axes. We find that k1 is independent of pressure, and that the temperature dependence of k1 is adequately described by the Arrhenius expression k1(T) = 1.91 x 10(exp -11)(230/J) cu cm/ molecule.s; the absolute accuracy of measured values for k1 is estimated to vary from +/- 20 percent at at T approximately 230 K to +/- 30 percent at T approximately 330 K. Our results demonstrate that the O((sup 3)P(sub j)) + BrO rate coefficient is significantly faster than previously 'guesstimated,' and suggest that the catalytic cycle with the O((sup 3)P(sub j)) + BrO reaction as its rate-limiting step is the dominant stratospheric BrO(x), odd-oxygen destruction cycle at altitudes above 24 km.
Document ID
Document Type
Reprint (Version printed in journal)
Thorn, R. P.
(Georgia Inst. of Tech. Atlanta, GA United States)
Cronkhite, J. M.
(Georgia Inst. of Tech. Atlanta, GA United States)
Nicovich, J. M.
(Georgia Inst. of Tech. Atlanta, GA United States)
Wine, P. H.
(Georgia Tech Research Inst. Atlanta, GA United States)
Date Acquired
August 17, 2013
Publication Date
April 9, 1997
Publication Information
Publication: Laboratory Investigations of Stratospheric Halogen Chemistry
ISSN: 0021-9606
Subject Category
Inorganic And Physical Chemistry
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.
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