Influence of anion structure on the liquid–liquid equilibria of 1-(3-hydroxypropyl)pyridinium cation based ionic liquid–hydrocarbon binary systems

Binary liquid–liquid equilibria for 10 systems containing an ionic liquid (1-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)-amide and 1-(3-hydroxypropyl)pyridinium trifluorotris(perfluoroethyl)phosphate) with a hydrocarbon (n-hexane, n-heptane, cyclohexane, benzene, toluene) were measured by dynamic method. The influence of anion structure of 1-(3-hydroxypropyl)pyridinium cation based ionic liquids on solubility of aliphatic and aromatic hydrocarbons is discussed.

Research highlights
► Binary LLE for ionic liquids and hydrocarbons.
► Diagrams typical for systems with upper critical solution temperature (UCST).
► Aromatic hydrocarbons have better solubility than aliphatic hydrocarbons.
► The solubility of hydrocarbons is lower for ionic liquid with [NTf2]− anion than that for [FAP]−.