Reactions between microhydrated superoxide anions and formic acid

Abstract

Reactions between water clusters containing the superoxide anion, O₂˙⁻(H₂O)_n (n = 0–4), and formic acid, HCO₂H, were studied experimentally in vacuo and modelled using quantum chemical methods. Encounters between microhydrated superoxide and formic acid were found to result in a number of different reactions, including (a) proton transfer, (b) ligand exchange, (c) H₂-elimination (affording microhydrated CO₄˙⁻), and (d) dihydrogen transfer (affording H₂O₂ and microhydrated CO₂˙⁻). The effect of reactant-ion hydration on reaction rates was investigated and the involved reaction mechanisms were elucidated.