Kinetics and product studies of the reaction ClO + BrO using discharge-flow mass spectrometry

Journal Article · Thu Jun 15 04:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100349a016· OSTI ID:6751491

Friedl, R R; Sander, S P ^[1]

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1. California Institute of Technology, Pasadena (USA)

The kinetics and product branching ratios of the BrO + ClO reaction have been characterized at 1 Torr of total pressure over the temperature range 220-400 K with the technique of discharge-flow mass spectrometry. The measured overall reaction rate coefficient is k{sub 1} = (4.70 {plus minus} 0.50) {times} 10{sup {minus}12} exp((320 {plus minus} 40)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. Three product channels, identified as Br + ClOO (1a), Br + OClO (1b), and BrCl + O{sub 2} (lc) have been quantified: k{sub 1a} = (2.9 {plus minus} 1.0) {times} 10{sup {minus}12} exp((217 {plus minus} 50)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}; k{sub 1b} = (1.6 {plus minus} 0.4) {times} 10{sup {minus}12} exp((426 {plus minus} 50)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}; k{sub 1c} = (5.8 {plus minus} 2.0) {times} 10{sup {minus}13} exp((168 {plus minus} 50)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. On the basis of these results, it is argued that the reaction mechanism for ClO + BrO, like those of halogen monoxide self-reactions, involves metastable intermediate formation. In addition, emphasis is placed on the significant impact of these results on current models of stratospheric ozone depletion, which neglect channel 1c and the temperature dependence of k{sub 1}.

• OSTI ID: 6751491
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:12; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ATMOSPHERIC CHEMISTRY
BRANCHING RATIO
BROMINE COMPOUNDS
CHEMISTRY
CHLORINE COMPOUNDS
DATA
DATA ANALYSIS
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
INFORMATION
KINETICS
LAYERS
LOW PRESSURE
MEASURING INSTRUMENTS
MEASURING METHODS
MEDIUM TEMPERATURE
NUMERICAL DATA
OXYBROMIDES
OXYCHLORIDES
OXYGEN COMPOUNDS
OXYHALIDES
OZONE LAYER
REACTION KINETICS