Rate coefficients for the reaction of iodine oxide with methyl peroxy radicals

Abstract

Pulsed laser photolysis radical generation is used to study the title reaction IO+CH3O2→products. Sensitive and selective laser-induced fluorescence detection of IO allows excess CH3O 2 conditions to be maintained throughout, ensuring minimal interference from other fast IO reactions. The rate coefficients, k 5(296 K)=(3.4±1.4)× 10-12 cm3 molecule-1 s-1, are obtained relative to a well-characterised reference value (k3 for IO+HO2). This result agrees well with a previous determination from this laboratory and demonstrates that the above reaction proceeds an order of magnitude slower than suggested in other recent experimental and theoretical studies. Implications for HOx production/O3 destruction within the marine boundary layer are briefly discussed. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.