Relative pK a of some anilinium derivatives in methanol, acetonitrile, and tetrahydrofurane solvents

In this study, the relative pK(a) values of nine anilinium derivatives in methanol (MeOH), acetonitrile (AN), and tetrahydrofurane (THF) solutions were successfully calculated with mean absolute deviations of 0.63, 0.68, and 0.75 pK(a) units, respectively. To this aim, their gas-phase basicities were computed using the CBS-QB3 composite method. Also, conductor-like polarizable continuum model (CPCM) with UAHF, UAKS and UA0 cavities and SM8 solvation models at HF/6-31+G(d) level of theory were applied for the calculation of the solvation Gibbs free energies. The obtained results indicate that there is reliable correlation between the experimental and computed pK(a) values in the studied solutions. Therefore, to extend the pK(a) database for anilines, correlation equations were used to predict the pK(a) values in the investigated solvents.