Ternary (liquid + liquid) equilibria for 3 systems containing ionic liquids {(1-ethyl-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate, 1-(2-hydroxyethyl)-3-methylimidazolium trifluorotris(perfluoroethyl)phosphate, ethyl-dimethyl-(2-methoxyethyl)ammonium trifluorotris(perfluoroethyl) phosphate) + thiophene + heptane} have been determined at T = 298.15 K. The selectivity and solute distribution ratio were calculated for investigated systems and compared with literature values obtained for other systems containing ionic liquids with [FAP] anions and [emim](+) cations. In each system, high solubility of thiophene and low solubility of heptane in the ionic liquid are observed. The experimental results have been correlated using NRTL model. The influence of the structure of ionic liquid on phase equilibria, selectivity and solute distribution ratio is discussed. (C) 2014 Elsevier Ltd. All rights reserved.