Kinetics of the IO radical .2. Reaction of IO with BrO

The rate coefficient for the IO + BrO --> products (1) reaction was measured using pulsed laser photolysis with a discharge flow tube for radical production and pulsed laser-induced fluorescence and UV absorption for detection of IO and BrO radicals, respectively. Reaction 1 was studied under pseudo-first-order conditions in IO with an excess of BrO between 204 and 388 K at total pressures of 6-15 Torr. The Arrhenius expression obtained for non-iodine atom producing channels is k(la)(T) = (2.5 +/- 1.0) x 10(-11) exp[(260 +/- 100)/T] cm(3) molecule(-1) s(-1) independent of pressure. The rate coefficient for the reaction BrO + BrO --> products (2) and the UV absorption cross sections of BrO as a function of temperature were also determined as part of this study. The implications of these results to the loss rate of stratospheric ozone are discussed.