Activity Coefficients at Infinite Dilution of Polar Solutes in 1-Butyl-3-methylimidazolium Tetrafluoroborate Using Gas−Liquid Chromatography

Abstract

Activity coefficients at infinite dilution of 17 polar solutes included linear and branched C1 to C5 alcohols, chlorinated methane, acetone, acetonitrile, ethyl acetate, 1,4-dioxane, and cyclohexanone in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate were determined by gas chromatography using the ionic liquid as the stationary phase. The measurements were carried out at temperatures between (303.15 and 343.15) K. From the temperature dependence of the limiting activity coefficients, partial molar excess enthalpies at infinite dilution of the organic solutes in the ionic liquid have been derived.

Utility of ionic liquids in analytical separations

“…Activity coefficients for aldehydes and esters are lower than alkenes and alkanes in agreement with previous studies of other ILs [20,21]. Other polar solutes [22] such as alkyl-alcohols, -ethers, and chloromethanes were also tested showing higher solubility, as compared to alkanes, due to attractive interactions with the IL ions. Analytical characterization of IL stationary phases for standard GC separations of solutes is described in the next section.…”

Activity Coefficients at Infinite Dilution of Organic Solutes in 1-Ethyl-3-methylimidazolium Tetrafluoroborate Using Gas−Liquid Chromatography

“…[1][2][3][4][5][6][7] Heintz et al [8][9][10][11][12][13][14][15][16] and Letcher et al [17][18][19][20][21][22][23][24][25] measured γ i ∞ of various solutes in a number of ILs.…”

Volumetric Properties of the Ionic Liquid, 1-Butyl-3-methylimidazolium Tetrafluoroborate, in Organic Solvents at T = 298.15K

“…It is one of the most commonly used ionic liquids for which some physicochemical properties with other organic solvents have been studied. Its volumetric properties, viscosity and speed of sound in water [10][11][12][13], vapor-liquid equilibria in binary and ternary mixtures [14], liquid-liquid equilibria [15][16][17], vapor pressures of binary [BMIm] [BF 4 ] + water mixture [18], activity coefficients at infinite dilution with some organic solvents [19,20], mutual solubilities of this ionic liquid in organic solvents [21,22], volumetric and viscosity study in organic solvents [23], excess thermodynamic functions of [BMIm] [BF 4 ]+H 2 O systems at 298.15 K [24], aggregation behavior in aqueous solutions [25], thermophysical properties in organic solvents [26,27], and dipolarity/polarizability and hydrogen-bond donating (HBD) acidity of aqueous [BMIm][BF 4 ] [28] have been reported.…”