REACTIONS OF O2H- AND ITS HYDRATES WITH CH3CN, CO2 AND SO2

Gas-phase hydrated anions O2H-(H2O)n = 0-2 are produced by a simple discharge ionization method, and their reactivities are studied in a fast flow reactor at room temperature. Rate constants for the reactions of O2H- and its hydrates with CH3CN, SO2 and CO2 are measured, and reaction mechanisms are proposed to account for the findings. In the case of CH3CN, dominant reaction channels for O2H- are proton transfer to form CH2CN- and a more complicated mechanism to form CN-; association and switching evidently may occur for reactions with O2H-(H2O)n = 1,2. For SO2 and CO2, the major reaction pathways are switching reactions leading to the formation of HCO3-(H2O)n, HSO3-(H2O)n and HSO4-(H2O)n. The effect of solvation, and some possible applications to atmospheric chemistry are also discussed.