Activity coefficients at infinite dilution gamma(infinity)(13) for 31 organic solutes (n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes, alcohols, and ketones) in the ionic liquid trihexyltetradecylphosphonium hexafluorophosphate [3C(6)C(14)P][PF6] were determined by gas-liquid chromatography at T = (313.15, 333.15, 353.15, and 363.15) K. From experimental values, the partial molar excess enthalpy values at infinite dilution, Delta H-1(E,infinity) together with the selectivity, S-ij(infinity), and the capacity, k(j)(infinity), (which are related to the separation of liquids) were calculated and compared to literature values for other ionic liquids, as well as industrial solvents. (C) 2012 Elsevier Ltd. All rights reserved.