Conductometric investigation of ion-solvent interactions of an ionic liquid {[emim]CH3SO3} in pure n-alkanols

Qualitative and quantitative analyses of molecular interaction prevailing in ionic liquid and organic solvent media, probed by electrical conductance have been reported. Conductometric studies of an ionic liquid {1-ethyl-3-methylimidazolium methanesulfonate [emim]CH3SO3} in n-propanol, n-butanol, and n-pentanol at 298.15 K reveal high molecular interaction contributed mainly by ion-dipole interaction. Association constants (KA), limiting molar conductance (Λ0), and the distance of closest approach of ions (R) for ion-pair formation have been analyzed using Fuoss conductance equation (1978). The molar conductivities observed were explained by the formation of ion-pairs (M+ + X¯ → MX). The Walden product is obtained and discussed. Molar refraction (RM) has been calculated using the Lorentz-Lorenz equation. The results show more association of the ions in n-pentanol than in n-propanol and results have been interpreted in terms of ion-solvent and solvent-solvent interaction. The extent of interaction has also been expressed in terms of the association constant (KA) and shows the ion-dipole interaction to be a function of viscosity.