Activity coefficients at infinite dilution and physicochemical properties for organic solutes and water in the ionic liquid 4-(3-hydroxypropyl)-4-methylmorpholinium bis(trifluoromethylsulfonyl)-amide

Abstract

The activity coefficients at infinite dilution, γ13∞ and (gas+liquid) partition coefficients, KL for 61 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, butanal, nitrogen compounds and water in the ionic liquid 4-(3-hydroxy)-4-methylmorpholinium bis(trifluoromethylsulfonyl)-amide were determined by (gas+liquid) chromatography at the temperatures from (298.15 to 368.15)K. The partial molar excess Gibbs free energies ΔG1E,∞, enthalpies ΔH1E,∞ and entropies ΔS1E,∞ at infinite dilution were calculated from the experimental γ13∞ values obtained over the temperature range. The selectivities and capacities at infinite dilution for selected extraction problems (water/butanol, hexane/benzene, heptane/thiophene) were calculated from the γ13∞ and compared to the literature values for other ionic liquids based on bis(trifluoromethylsulfonyl)-amide anion. The values of KL were used to determine the linear free energy relationship (LFER) system constants as a function of temperature. The density and viscosity of the investigated ionic liquid at temperatures from (298.15 to 368.15)K as well as other physicochemical properties: temperature of fusion and glass transition temperature were also measured.