Quaternary (liquid + liquid) equilibria for systems of imidazolium based ionic liquid + thiophene + pyridine + cyclohexane at 298.15 K: Experiments and quantum chemical predictions

► Quaternary (liquid + liquid) equilibria are measured for ionic liquids, cyclohexane, pyridine and thiophene. ► Extraction of thiophene and pyridine from cyclohexane using ionic liquids is investigated. ► Three different ionic liquids are investigated. ► The experimental data can be successfully correlated using NRTL and UNIQUAC models. ► The experimental data are in moderate agreement with a priori predictions made using the COSMO-SAC model.