Activity coefficients at infinite dilution (gamma(infinity)(i)) and gas-liquid partition coefficients (K-L) for organic solutes: n-alkanes, alkenes, alkyl benzenes, acetonitrile, acetone, tetrahydrofuran, ethyl acetate, and chloromethanes in the ionic liquid (IL) 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide GFIMMIMI[NTf2]) have been measured by the gas -liquid chromatographic method (GLC) in the temperature range of (313.15-353.15) K. The thermodynamic functions at infinite dilution as partial molar excess enthalpies at infinite dilution (H,E') were derived from the temperature dependence of the y, values. Gibbs energies ((G) over bar (E,infinity)(i)) and entropies (Tref (S) over bar (E,infinity)(i)) of organic solutes in [HMMIM][NTf2] at a reference temperature T-ref = 298.15 K were also calculated from the 7,7 values. The solubility parameters of the IL [HMMIM][NTf2] were determined by two methods. Selectivity (Sr) and capacity (V) at infinite dilution at 323.15 K have been determined for n -hexane (i)/benzene (j), cyclohexane (i)/benzene (j). The results were analyzed in comparison to literature data for alkylimidazolium-based ILs with [NTf2]. For three isomeric xylenes separation problems, selectivity at 323.15 K were also obtained from the 7,7 values. (C) 2016 Elsevier Ltd.