Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The solubilities of C2H4 and CO2 and the interactions of polar and nonpolar solutes with the novel ionic liquids (ILs) 1-butyronitrile-3-methylimidazolium bis(trifluoromethylsulfonyl) imidate (CpMIm[NTf2]), 1-butyronitrile- 2,3-dimethylimidazolium bis(trifluoromethylsulfonyl) imidate (CpMMIm[NTf2]), 1-butyronitrile-3-methylimidazolium dicyanamide (CpMIm[N(CN)2]), 1-butyronitrile-2,3-dimethylimidazolium dicyanamide (CpMMIm- [N(CN)2]), 1-butyl-3-methylimidazolium palmitate (BMIm[n-C16H33COO]), and 1-butyl-3-methylimidazolium stearate (BMIm[n-C18H35COO]) were studied by gas chromatography at infinite dilution at T ) (303.15, 313.15, 323.15, and 333.15) K. Henry s law constant kH of C2H4 and CO2 gas, infinite dilution activity coefficient cyen, molar enthalpies of solution centssolHyen, and partial molar excess enthalpies of solution centsHEyen and of Gibbs energies centsGEyen were determined for polar and nonpolar solutes in these novel ILs. Compared with the 1,3-dialkylimidazolium ILs, cyano functional group substitution on the alkyl chain results in a remarkable decrease of the interactions of hydrocarbons. BMIm[n-C16H31OO] and BMIm[n-C18H35OO] demonstrate strong solubilization for both polar and nonpolar solutes. Straight lines of ln Vg versus 1/T and ln cyen versus 1/T were obtained for the majority of solutes in the temperature range. BMIm[NTf2] and 1-octyl-3-methylimidazolium tetrafluoroborate (OMIm[BF4]) show much better solubility for thiophene and are better solvents for the separations of thiophene from hydrocarbons.