Activity coefficients at infinite dilution (gamma(infinity)(13)) for 34 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, acetone, and water in the ionic liquid 1-hexyl-3-methylimidazolium thiocyanate ([hmim][SCN]) were determined by gas liquid chromatography over temperature range from (298.15 to 368.15) K. The partial molar excess enthalpies at infinite dilution values (AM:) were calculated from the experimental gamma(infinity)(13) values, obtained over the temperature range. The selectivities for aliphatic/aromatic hydrocarbon separation problems were calculated from the gamma(infinity)(13) and compared to the literature values for other ionic liquids with a thiocyanate-based anion or a -C N group in an anion or a cation, N-methyl-2-pyrrolidinone (NMP) and sulfolane.