Møller-Plesset perturbation theory calculations of the pKa values for a range of carboxylic acids

This work presents calculated values of the pKa for a series of carboxylic acids spanning a wide range of acidities, using quantum mechanical treatment of solute electronic structure in conjunction with a dielectric continuum model for solvation. The calculations are carried out using 3rd order Møller-Plesset perturbation theory. Solute-solvent interactions have been taken into account by employing the polarizable continuum model (PCM). The calculated pKa values are in significantly better agreement with experimental data for the majority of the acids studied than other recently published results. The mean absolute deviation of the calculated pKa values is 0.68 in pKa units, for the carboxylic acids considered.