Thermodynamics and activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 1-butyl-1-methylpyrrolidinium tetracyanoborate

Abstract

The activity coefficients at infinite dilution, γ 13 ∞ , for 45 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water, in the ionic liquid 1-butyl-1-methylpyrrolidinium tetracyanoborate, [BMPYR][TCB], were determined by gas–liquid chromatography at temperatures from 318.15 K to 368.15 K. The values of the partial molar excess Gibbs free energy Δ G 1 E, ∞ , enthalpy Δ H 1 E, ∞ , and entropy Δ S 1 E, ∞ at infinite dilution were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The gas–liquid partition coefficients, K L were calculated for all solutes and the Abraham solvation parameter model was discussed. The values of the selectivity for different separation problems were calculated from γ 13 ∞ and compared to literature values for N-methyl-2-pyrrolidinone (NMP), sulfolane, 1-ethyl-3-methylimidazolium tetracyanoborate, [EMIM][TCB], 1-decyl-3-methylimidazolium tetracyanoborate, [DMIM][TCB], and similar ionic liquids. The densities of [BMPYR][TCB] in temperatures range from 318.15 K to 368.15 K, the temperature of fusion and the enthalpy of fusion were measured.