Measurements of activity coefficients at infinite dilution in solvent mixtures with thiocyanate-based ionic liquids using GLC technique.

The activity coefficients at infinite dilution, gamma13(infinity) for 34 solutes--alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, and ketones--in the ionic liquid 1-butyl-4-methylpyridinium thiocyanate, [BMPy][SCN], and in 1-butyl-1-methylpyrrolidinium thiocyanate, [BMPYR][SCN], were determined by gas-liquid chromatography at the temperature range from 298.15 to 368.15 K. The partial molar excess enthalpies at infinite dilution values, DeltaH1E,infinity, were calculated from the experimental gamma13(infinity) values obtained over the temperature range. The selectivities for the n-heptane/benzene, cyclohexane/benzene, and n-heptane/thiophene separation problems were calculated from the gamma13(infinity). Obtained values were compared to the literature values for the other ionic liquids, NMP, and sulfolane.