Temperature dependencies of the reactions of CO−3(H2O)0,1 and O−3 with NO and NO2

Abstract

We have measured temperature dependencies of the rate constants for CO−3 and O−3 reacting with NO and NO2. In addition, the temperature dependence of the CO−3(H2O) reaction with NO was determined, and a 196 K rate constant was measured for the reaction of CO−3(H2O) with NO2. The reactions with NO all proceed by O− transfer to produce NO−2. The temperature dependencies of the rate constants for the reactions of CO−3 and O−3 with NO are represented as 1.5×10−7*T−1.64 and 4.4×10−7*T−2.15 cm3 s−1, respectively, and agree very well with previous measurements. The rate constant for the reaction of CO−3(H2O) with NO is 4.1×10−5*T−2.72 cm3 s−1. Previous measurements of the rate constants for CO−3, CO−3(H2O), and O−3 reacting with NO2 appear to be in error; our measured rate constants for the first two reactions are represented as 2.6×10−5*T−2.38 and 9.1×10−9*T−0.79 cm3 s−1, respectively. The rate constant for the reaction CO−3(H2O) with NO2 is 7.9×10−11 cm3 s−1 at 196 K. The reactions of CO−3 and CO−3(H2O) with NO2 proceed by O− transfer, producing NO−3. While the reaction of O−3 with NO2 proceeds mainly by charge transfer at room temperature, about half the reactivity at 200 K is due to charge transfer with the remainder arising from O− transfer. Atmospheric implications of the present results are discussed.