The Microscopic Free Energies of Solvation for K + , Rb + and Cs + in Mixed Methanol (MeOH)-Dimethylformamide (DMFA) Solvents at 298.15 K

The microscopic charging (∆ Gt charging), ion-dipole (∆ Gt ion-dipole) and ion-induced dipole (∆ Gt ion- induced dipole) free energies of transfer for some ions from methanol to mixed methanol (MeOH)-dimethylformamide (DMFA) solvents were calculated. These ions are potassium, rubidium and cesium. These theoretical free energies were compared with that of experimental values and the difference excess free energies of solvation were discussed. I t was ob- served that the excess free energies for all ions are positive and follow the following order: ∆ GT (excess) K + > ∆ GT (excess) Rb + > ∆ GT (excess) Cs + . Indicating more solvation behaviour by increasing the percentage of DMFA in the mixed solvents due to more attraction of these ions in the range rich in DMFA