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Title: Kinetics and product studies of the reaction ClO + BrO using flash photolysis-ultraviolet absorption

Journal Article · · Journal of Physical Chemistry; (USA)
DOI:https://doi.org/10.1021/j100349a017· OSTI ID:6735707
;  [1]
  1. 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), Vol. 93:12; ISSN 0022-3654
Country of Publication:
United States
Language:
English