Thermodynamics and activity coefficients at infinite dilution for organic compounds and water in the ionic liquid 1-butyl-3-methylimidazolium perchlorate

Activity coefficients at infinite dilution (gamma(infinity)(i)) and (gasliquid) partition coefficients (K-L) for organic compounds (alkanes, alkenes, alkyl benzenes, acetonitrile, acetone, tetrahydrofuran, ethyl acetate, 1,4-dioxane, chloromethanes, and alcohols) and water in the ionic liquid (IL) 1-butyl-3-methylimidazolium perchlorate ([BMIM][ClO4]) have been measured by the (gas-liquid) chromatographic method in the temperature range of (303.15353.15) K. Density, rho as a function of temperature for [BMIM][ClO4] at pressure p = 101.3 kPa were measured. The values of the partial molar excess enthalpies at infinite dilution ((H) over bar (E,infinity)(i)) were derived from the temperature dependence of the gamma(infinity)(i) values. The entropies (T-ref(S) over bar (E,infinity)(i)) and Gibbs free energies ((G) over bar (E,infinity)(i)) of organic solutes in [BMIM][ClO4] at a reference temperature T-ref = 298.15 K were also calculated from the gamma(infinity)(i) values. The Hildebrands solubility parameters of the IL [BMIM][ClO4] were also determined by the regular solution theory (RST) combined with Flory combinatorial equation. Selectivity (S-ij(infinity)) and capacity (k(j)(8)) 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 values for 1-buthyl-3-methylimidazolium-based ionic liquids (ILs) for the same separation problems. For three isomeric xylenes separation problems, selectivity at 323.15 K were also obtained from the gamma(infinity)(i) values. (C) 2017 Elsevier Ltd.