Group additivity approach for determination of solvation enthalpies of aromatic compounds in 1-butyl-3-methylimidazolium tetrafluoroborate based on solution calorimetry data

Abstract

© 2017 Elsevier B.V.In this work thermochemistry of solvation of mono-, di-, tri- and tetra-substituted benzenes in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) ionic liquid was studied. Enthalpies of solution at infinite dilution of 34 substituted benzenes in [BMIM][BF4] were measured at 298.15 K using solution calorimetry technique. Based on the experimental and literature data enthalpies of solvation of 36 substituted benzenes in [BMIM][BF4] were calculated. It was shown that enthalpies of solvation of substituted benzenes in [BMIM][BF4] are independent on the mutual position of subtituents and dipole moment of molecules. Group contribution scheme for prediction of enthalpies of solvation of substituted benzenes was applied. Values of methyl- (CH3), tert-butyl- (tert-C4H9), bromo- (Br), iodo- (I), amino- (NH2), methoxy- (OCH3), dimethylamino- (N(CH3)2), methylcarboxylate- (COOCH3) group contributions to the enthalpies of solvation in [BMIM][BF4] were derived and compared with molecular solvents. Solvation enthalpies of substituted benzenes in [BMIM][BF4] calculated through group contribution scheme were in good agreement with experimental data.