Properties of Pure 1-Butyl-2,3-dimethylimidazolium Tetrafluoroborate Ionic Liquid and Its Binary Mixtures with Dimethyl Sulfoxide and Acetonitrile

Abstract

This work presents density and dynamic viscosity data for the pure ionic liquid, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [Bmmim] [BF 4 ], and its binary mixtures with the highly polar solvents dimethylsulfoxide (DMSO) and acetonitrile (ACN), over the entire range of composition and temperatures from (298.15 to 353.15) K at atmospheric pressure. The properties have been represented with temperature by specific equations, both for pure [Bmmim] [BF 4 ] and its binary mixtures. Therefore, an empirical linear equation was used for density variation and for viscosity, the Vogel−Fucher−Tammann (VFT) equation. From the density data the excess molar volume, V E , apparent molar volume, V ϕi , and partial molar volume, V̅ mi , as well as thermal expansion coefficient, α p , have been evaluated. Moreover, the excess molar volume was fitted to the Redlich− Kister polynomial equation, and its variation with composition has been qualitatively discussed in terms of interaction and structural factors. ■ INTRODUCTIONIonic liquids (ILs) are a class of substances extensively studied by the scientific community because of their interesting properties such as a negligible vapor pressure, low melting point, suitable viscosity, high conductivity, wide electrochemical windows, and high stability, which makes them suitable for a diversity of applications, especially as solvents. 1−4 These solvents are called "green" because of their low vapor pressure and nonflammability.One of the most studied ILs are 1,3-alkyl-substituted imidazolium-based, whose properties can be modified by changing cation/anion combinations. Some of these properties can also be changed by replacing the hydrogen atom at position 2 of the imidazole ring with alkyl substituents. 5−7 The trialkylsubstituted imidazolium-based ILs are considered by some researcher groups to be promising material for electrochemical applications, 8−11 inorganic synthesis, 12 or enzymatic catalysis. 13 Our interest for the trialkyl-substituted imidazolium-based ILs is on the one hand to study the physicochemical properties of solvent systems with ILs that can be used as new media in the synthesis of different metal oxide nanostructures; in this sense we have already studied three 1-alkyl-3-methylimidazolium tetrafluoroborate ILs. 19,20 On the other hand the binary mixtures of such trialkyl-substituted imidazolium-based ILs with organic solvents are interesting from the fundamental research point of view for understanding the relation between structure and mixture properties, especially by comparing them with corresponding dialkyl-substituted mixtures.Therefore, in this paper we extended our studies on physicochemical properties of dialkyl-substituted 19,20 to trialkyl-substituted imidazolium ILs systems, with the same organic solvents, dimethylsulfoxide (DMSO) and acetonitrile (ACN). Also, it was interesting to comparatively discuss the volumetric behavior of these systems and to analyze the influence of cation nature or solvent type on the reported properties.The studies on th...

Interaction of 1-Butyl-3-methylimidazolium Trifluoromethanesulfonate with Ethyl Acetate/1-Butanol: Thermophysical Properties

“…Ionic liquids (ILs) have been demonstrated to be potential successful replacements for conventional solvents for catalysis and synthesis [1,2] because of their unique physical and chemical properties, including non-volatility, thermal stability, negligible vapor pressure, reusability, and wide electrochemical windows [3]. The ILs can also control miscibility [4,5].…”

“…Macedo et al [10] reported the densities, speeds of sound and refractive indices for [BMIM][CF 3 SO 3 ]-water binary mixtures over the whole composition range, at T = (288. 15-308.15) K and atmospheric pressure.…”

“…Patek et al [11] reported the densities of the pure [BMIM][CF 3 SO 3 ] in the range of (268-356) K. Ge et al [12] reported the densities and viscosities of binary mixtures of [BMIM][CF 3 SO 3 ] with water over the entire mole fraction range from (303.15 to 343.15) K at atmospheric pressure. Romani et al [13] reported the excess enthalpy and density data for binary mixtures of [BMIM][CF 3 SO 3 ] with water in the temperature range (293. 15-318.15) K. Martinez-Andreu et al [14] reported the densities and speeds of sound of binary mixtures of [BMIM][CF 3 SO 3 ] with water at p = (101 ± 2) kPa and T = (278.…”

“…Romani et al [13] reported the excess enthalpy and density data for binary mixtures of [BMIM][CF 3 SO 3 ] with water in the temperature range (293. 15-318.15) K. Martinez-Andreu et al [14] reported the densities and speeds of sound of binary mixtures of [BMIM][CF 3 SO 3 ] with water at p = (101 ± 2) kPa and T = (278. 15-338.15) K, covering the whole range of concentration.…”

“…15-338.15) K, covering the whole range of concentration. A thorough literature survey reveals that no study on thermophysical properties has been reported for mixtures of [BMIM][CF 3 SO 3 ] with organic solvents.…”