Thermodynamics of the acid dissociation of tertiary aliphatic ammonium ions in 60% w/w methanol–water solution and of the quinuclidinium ion in water

Abstract

Values of ΔG^⊖, ΔH^⊖, ΔS^⊖, and ΔC_p^⊖ are reported for the acid dissociation of the quinuclidinum ion in water and of the following ions in 60% w/w methanol–water solution: trimethyl-, triethyl-, tri-n-propyl-, and tri-n-butylammonium and quinuclidinium. An e.m.f. method was used. The results indicate that hydrophobic solvation is important and that in the mixed solvent there is evidence for selective solvation of the ammonium ions by water.