GAS-PHASE REACTIONS OF CLONO2 WITH CL-(D2O)(N=0-3) AND NO2-

The reactions of ClONO2 with the Cl-(D2O)(n less than or equal to 3) a nd NO2- ions were studied in a flow-tube apparatus at several temperat ures in the range 170-298 K and at a helium buffer gas pressure of 0.2 8 Torr. Rate constants for these reactions were determined, establishi ng that all these ions react quite efficiently with ClONO2. The produc t ions observed in reaction sequences are reported, and reaction mecha nisms are proposed to account for the findings. In the case of Cl- and NO2- the main product ion is NO3-, while the hydrates Cl-(D2O)(n less than or equal to 1-3) lead to production of the hydrated species, NO3 -(D2O)(m less than or equal to n-1). The main features of the observed secondary reactions can be described in terms of adduct formation and ligand switching. Limits on the bond energy of (NO3ClNO3)-, 14.6 kcal /mol less than or equal to D(NO3--ClONO2) less than or equal to 26 kca l/mol, were determined. Finally, implications of these studies to atmo spheric chemistry are discussed.