Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 1-(2-methoxyethyl)-1-methylpiperidinium trifluorotris(perfluoroethyl)phosphate

This work is continuation of our systematic study of activity coefficients at infinite dilution, γ∞ of different organic solutes and water in the ionic liquids. New data of γ∞ were determined for 62 solutes, including alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, 1-nitropropane, butanal, acetonitrile, and water in the ionic liquid 1-(2-methoxyethyl)-1-methylpiperidinium trifluorotris(perfluoroethyl)phosphate by inverse gas chromatography at the temperature range from (318.15 to 368.15) K. The basic thermodynamic functions, namely partial molar excess Gibbs free energies, ΔG1E,∞, enthalpies, ΔH1E,∞ and entropies, ΔS1E,∞ at infinite dilution were calculated from the experimental γ∞ values obtained over the temperature range. Additionally the gas–liquid partition coefficients, KL were determined. Results are compared to previously investigated ionic liquids with the same cations or anions. Values of the selectivity and capacity at infinite dilution for heptane/benzene, heptane/thiophene, and heptane/methanol extraction problems were calculated from experimental γ∞ values to verify the possibility of investigated ionic liquid as an entrainer in liquid–liquid extraction.

► IGC was used to determine γ∞ and KL for 62 solutes in the ionic liquid [COC2mPIP][FAP].
► Partial molar excess Gibbs free energies ΔG1E∞, enthalpies ΔH1E∞, and entropies ΔS1E∞ were calculated.
► Selectivities and capacities for selected separation problems were calculated.
► LFER system constants as a function of T for [COC2mPIP][FAP] were calculated.