Probing molecular interactions of ionic liquid in industrially important solvents by means of conductometric and spectroscopic approach

Qualitative and quantitative analysis of molecular interaction prevailing in ionic liquid-organic solvent media, probed by electrical conductances and FT-IR measurements have been reported. Conductometric studies of 1-ethyl-3-methylimidazolium bromide [EMIm]Br in acetonitrile (AN), methanol (MeOH), N,N-dimethyl formamide (DMF), N,N-dimethyl acetamide (DMA) and dimethyl sulphoxide (DMSO) at 298.15 K reveals high molecular interaction contributed mainly by ion–dipole interaction as evident from the FT-IR measurements. The extent of interaction is expressed in terms of the association constant (KA) and shows the ion–dipole interaction to be a function of viscosity. The interaction obtained is highest in case of DMSO in comparison to the other solvents. The greater share of the conductance of [EMIm]Br in different solvents comes from the Br− ion than the [EMIm]+ ion as evident from their ionic conductance values which is estimated from the appropriate division of the limiting molar conductivity value of tetrabutylammonium tetraphenylborate [Bu4NBPh4] as the “reference electrolyte” method.