The properties of clusters in the gas phase. IV. Complexes of H2O and HNOx clustering on NOx−

Thermodynamic quantities for the gas-phase clustering equilibria of NO2− and NO3− were determined with high-pressure mass spectrometry. Comparison of ΔG°n,n+1 values derived from our data shows good agreement with formerly reported values at 296 °K. New data for larger NO2− and NO3− hydrates as well as NO2−(HNO2) were obtained in this study. To aid in understanding the bonding and stability of the hydrates of nitrite and nitrate ions, CNDO/2 calculations were performed, and the results are discussed herein. A correlation between the aqueous phase total hydration enthalpy of a single ion and its gas-phase hydration enthalpy was obtained. Atmoshperic implications of the data are also briefly discussed.