Thermodynamic data interpretation of the ion association process in mixed solvents

Inhibition of Catalytic Activity in Ionic Liquids: Implications for Catalyst Design and the Effect of Cosolvents

“…It was surprising to observe negative values for both enthalpy and entropy, but this is due to solvent effects. The integral thermodynamic characteristics, which were fitted with the Ives and Pryor equation, can be divided into two components, namely, a van't Hoff component, Δ r H T , which directly describes the bonds involved in the equilibrium, and a dielectric component, Δ r H ε , related to the solvent effects. , The determination of the van't Hoff component, previously reported for various ionic association equilibria in acetonitrile, was performed through the calculation of the dielectric contribution using Ebeling's equation . Accordingly, for the dissociation of [bmim]Cl in acetonitrile, using a dielectric contribution, Δ r H ε , of −16.6 kJ/mol at 298 K, the van't Hoff component, Δ r H T , was found to be equal to 15.4 kJ/mol, which is an estimation of the H-bond dissociation enthalpy.…”