Solvation thermochemistry of aromatic hydrocarbons and their halogen derivatives in imidazolium-based ionic liquids

Abstract

In this work solution enthalpies of aromatic compounds and their halogen derivatives in 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [BMIM][NTf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][TfO] were measured by solution calorimetry method. The solvation enthalpies of aromatic compounds and their halogen derivatives in ionic liquids were calculated. Based on experimentally measured solvation enthalpies and calculated non-specific solvation enthalpy the contribution of the solvophobic effect on the solvation enthalpy of dissolved molecules in ionic liquids was demonstrated to be negligible. The correlation between solvation enthalpies of the aromatic compounds and their halogen derivatives in ionic liquids and solute molecules polarizability parameter was found. Also, a comparison of relationships between solvation enthalpy and molar refractions in ionic liquids and molecular solvents was made.