KINETICS OF THE IO RADICAL .2. REACTION OF IO WITH BRO

The rate coefficient for the IO + BrO --> products (1) reaction was me asured using pulsed laser photolysis with a discharge flow tube for ra dical production and pulsed laser-induced fluorescence and UV absorpti on for detection of IO and BrO radicals, respectively. Reaction 1 was studied under pseudo-first-order conditions in IO with an excess of Br O 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 o zone are discussed.