Structure of the HOOO radical in liquid water: a theoretical study

The HOOO radical is supposed to play a role in ozone chemistry, both in the gas phase and aqueous media. We discuss the influence of the solvent on the electronic and geometrical structure of this radical using density functional and high-level ab initio calculations together with continuum, discrete, and discrete-continuum solvent models. Solute-solvent electrostatic interactions are shown to be fundamental, and lead to a noticeable stabilization of the radical, which should adopt a trans conformation in aqueous media. In fact, no energy minimum for the cis conformation is predicted in these conditions.