Solvation Enthalpies and Gibbs Energies of the Proton and Electron - Influence of Solvation Models

A comprehensive examination of the solvation enthalpies and Gibbs energies of the proton and electron in twenty solvents of different polarities was carried. Eleven quantum mechanical methods were applied in conjunction with the 6-311++G(d,p) basis set and C-PCM solvation model. It was found that different methods produce consistent values for the solvation enthalpy and Gibbs energy of the proton in all solvents, while the corresponding values for the electron are mutually notably different. The fact that the Minnesota functionals often produced inconsistent solvation enthalpy and Gibbs energy values of the electron indicates their unreliable performance without the corresponding SMD solvation model, whereas other studied methods only slightly depend on solvation models. A comparison of the results of the present investigation to those obtained by employing SMD reveals that C-PCM produces slightly more negative (less positive) solvation enthalpies and Gibbs energies of the electron, and less negative values for the proton. These results are also in accord with the literature data where the IEF-PCM solvation model was used.