Upper limit for the rate coefficient for the reaction of OH with N2O5

Abstract

An upper limit for the rate coefficient for the reaction of

was measured to be 5.7×10⁻¹⁵ cm³ molecule⁻¹ s⁻¹ at 240 K. OH radicals were produced ia pulsed photolysis of a mixture of O₃ and H₂, ia the reaction of O(¹D) with H₂, in the presence of an excess of N₂O₅ with SF₆ as the bath gas. The temporal profiles of OH, which followed pseudo-first order kinetics, were monitored by laser induced fluorescence. Concentrations of N₂O₅ were determined by UV/visible absorption. Using this limit for k₁, the potential role of N₂O₅ loss and conversion to HNO₃ due to reaction (1) in the stratosphere is deduced to be negligible relative to known pathways.