TEMPERATURE DEPENDENCIES OF THE REACTIONS OF CO3-(H2O)(0,1) AND O-3(-) WITH NO AND NO2

We have measured temperature dependencies of the rate constants for CO 3- and O-3(-) reacting with NO and NO2. In addition, the temperature d ependence of the CO3-(H2O) reaction with NO was determined, and a 196 K rate constant was measured for the reaction of CO3-(H2O) with NO2. T he reactions with NO all proceed by O- transfer to produce NO2-. The t emperature dependencies of the rate constants for the reactions of CO3 - and O-3(-) with NO are represented as 1.5X10(-7)T--1.64 and 4.4X10( -7)T--2.15 cm(3) s(-1), respectively, and agree very well with previo us measurements. The rate constant for the reaction of CO3-(H2O) with NO is 4.1X10(-5)T--2.72 cm(3) s(-1). Previous measurements of the rat e constants for CO3-, CO3-(H2O), and O-3(-) reacting with NO2 appear t o be in error; our measured rate constants for the first two reactions are represented as 2.6X10(-5)T--2.38 and 9.1X10(-9)*T--0.79 cm(3) s( -1), respectively. The rate constant for the reaction CO3-(H2O) with N O2 is 7.9X10(-11) cm(3) s(-1) at 196 K. The reactions of CO3- and CO3- (H2O) with NO2 proceed by O- transfer, producing NO3-. While the react ion of O-3(-) with NO2 proceeds mainly by charge transfer at room temp erature, 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. (C) 1995 American Institute of P hysics.