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

In this work thermochemistry of solvation of mono-, di-, tri- and tetra-substituted benzenes in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]) ionic liquid was studied. Enthalpies of solution at infinite dilution of 34 substituted benzenes in [BMIM][BF 4 ] 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][BF 4 ] were calculated. It was shown that enthalpies of solvation of substituted benzenes in [BMIM][BF 4 ] 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- (CH 3 ), tert -butyl- ( tert -C 4 H 9 ), bromo- (Br), iodo- (I), amino- (NH 2 ), methoxy- (OCH 3 ), dimethylamino- (N(CH 3 ) 2 ), methylcarboxylate- (COOCH 3 ) group contributions to the enthalpies of solvation in [BMIM][BF 4 ] were derived and compared with molecular solvents. Solvation enthalpies of substituted benzenes in [BMIM][BF 4 ] calculated through group contribution scheme were in good agreement with experimental data. [ABSTRACT FROM AUTHOR]