Study of the H+ and OH− Hydrated Ions by the CNDO/2 Method

Abstract

The ions obtained by hydration of H⁺ and OH⁻, e.g., H₃O⁺, H₅O₂, H₇O₃, H₉O₄⁺, H₃O₂⁻, H₅O₃⁻, and H₇O₄⁻ have been studied theoretically using the CNDO/2 method. The results indicate chain structures are generally preferred albiet weakly over cyclic structures by the total energy criterion and in the case of positive ions over proton centered structures. Binding energies are found to be in reasonable agreement with experimental data. Charge distributions and individual bond energy effects have been examined in detail and are generally consistent with the notion that protons serve as bridging centers for delocalization which remain strongly positive throughout both series to shield the fragment oxygens from each other.