Conductometric, refractometric and FT-IR spectroscopic study of [EMIm]NO3, [EMIm]CH3SO3, and [EMIm]OTs in N,N-dimethyl formamide, N,N-dimethyl acetamide and dimethyl sulphoxide

摘要

The molecular interactions existing in ionic liquid-organic solvent have been done, both qualitatively and quantitatively, by means of electrical conductance, molar refraction and FT-IR measurements. Conductometric studies of 1-ethyl-3-methylimidazolium nitrate, 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium tosylate in N,N-dimethyl formamide, N,N-dimethyl acetamide and dimethyl sulphoxide at 298.15 K reveals high molecular interaction between the solute and the solvent which is mainly contributed by ion-dipole interaction as manifested from the FT-IR measurements. The interaction is highest in case of 1-ethyl-3-methylimidazolium tosylate and dimethyl sulphoxide than others. The larger share of the conductance of imidazolium based ionic liquid in unlike solvents comes from anion than cation as evident from their individual ionic conductance values which is estimated from the suitable allotment of the limiting molar conductivity value of tetrabutylammonium tetraphenylborate as "reference electrolyte" method. The molecular polarizability also observed to be highest in case of dimethyl sulphoxide as visible from refractive index information. (C) 2014 Published by Elsevier B.V.