Structures and binding energies of O2−·H2O and O2·H2O

Abstract

High-level ab initio calculations are employed to calculate the minimum energy structures for the O2−·H2O and O2·H2O complexes, with QCISD/aug-cc-pVTZ being the highest level used for the optimizations. Single-point RCCSD(T)/aug-cc-pVQZ calculations are then employed. The anion is found to have a very flat potential energy surface, with the molecule likely to be performing large-amplitude motion at the zero-point energy level. The neutral species is found to be of Cs symmetry and very weakly bound. The vertical and adiabatic electron affinities of the O2·H2O complex are calculated, with our best value for the adiabatic electron affinity being 1.22 ± 0.05 eV. Our best value for the binding energies, De, are 7116 cm−1 and 126 cm−1 for O2−·H2O and O2·H2O, respectively.