Determination of the absolute solvation free energy and enthalpy of the proton in solutions

The absolute solvation energies (free energy and enthalpy) of the proton in solution is of great importance for biological and chemical processes in that solution. The absolute solvation free energy of the proton is used to compute the pk(a) (acids proton dissociation constant) of organic compounds. Furthermore, these absolute solvation energies are used in the development of continuum solvation models and force fields. They are also used to determine the absolute solvation energies of other ions. Despite their importance, the absolute solvation energies of the proton cannot be determined experimentally. In the last century, several methodological approaches have been proposed to determine the absolute solvation energies of the proton in solution. In this review, we present recent and important methodologies used in the last two decades to evaluate the absolute solvation energies of the proton in solutions. In addition, we reviewed and discussed the absolute solvation energies of the proton in water, methanol, ammonia, acetonitrile, dimethylsulfoxide (DMSO), ethanol and other solvents reported in the literature in the last two decades. Finally, featured directions and methodologies which could be very promising are presented and discussed as perspectives. (C) 2020 Elsevier B.V. All rights reserved.