Kinetics and product studies of the reaction ClO + BrO using flash photolysis-ultraviolet absorption
- California Institute of Technology, Pasadena (USA)
The flash photolysis-ultraviolet absorption method has been used to study the BrO + ClO reaction over the pressure range 50-700 Torr and temperature range 220-400 K. The rate constant for the overall reaction is given by k{sub 1} = (6.1 {plus minus} 1.2) {times} 10{sup {minus}12} exp((240 {plus minus} 60)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} ({plus minus} 2{sigma} error limits). Branching ratios for the reaction channel forming OClO were determined at 220 and 209 K and found to be 0.68 {plus minus} 0.10 and 0.59 {plus minus} 0.10, respectively. Absolute UV absorption cross sections for ClO and BrO were determined as a function of temperature at the peaks of the 12-0 and 7-0 bands. In order to more fully understand the reaction mechanism used in the BrO + ClO study, the reactions Br + Cl{sub 2}O {yields} ClO + BrCl and Cl{sub 2}O + hv {yields} products were examined. The Arrhenius expression for the Br + Cl{sub 2}O reaction was found to be k{sub 3} = (2.1 {plus minus} 1.8) {times} 10{sup {minus}11} exp(-(520 {plus minus} 260)/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} ({plus minus}2{sigma}) over the temperature range 220-298 K. The quantum yield for the production of atomic oxygen from broad-band Cl{sub 2}O photolysis ({lambda} > 180 nm) was found to be 0.25 {plus minus} 0.05.
- OSTI ID:
- 6735707
- 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
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540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ATMOSPHERIC CHEMISTRY
BROMINE COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE COMPOUNDS
DATA
DATA ANALYSIS
DECOMPOSITION
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
INFORMATION
KINETICS
LAYERS
LOW PRESSURE
MEASURING INSTRUMENTS
MEASURING METHODS
MEDIUM TEMPERATURE
NUMERICAL DATA
OXYBROMIDES
OXYCHLORIDES
OXYGEN COMPOUNDS
OXYHALIDES
OZONE LAYER
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
REACTION KINETICS