Reactions of hydrated electrons (H2O)n- with carbon dioxide and molecular oxygen:: Hydration of the CO2- and O2- ions

The gas-phase reactions of hydrated electrons with carbon dioxide and molecular oxygen were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Both CO2 and O-2 react efficiently with (H2O)(n)(-) because they possess low-lying empty pi* orbitals. The molecular CO2- and O-2(-) anions are concurrently solvated and stabilized by the water ligands prediction based on density functional theory calculations that O-2(-)(H2O)(n) clusters are thermodynamically favored with respect to CO2-(H2O)(n). Electron detachment from the product species is only observed for CO2-(H2O)(2), in agreement with the calculated electron affinities and solvation energies.