Structure of Ionic Liquid−Benzene Mixtures

Abstract

Neutron diffraction has been used to investigate the structure of liquid mixtures of 1,3-dimethylimidazolium hexafluorophosphate with benzene. Two concentrations of benzene were investigated, namely, 33 mol % and 67 mol %, and show similar structures in each case. The presence of benzene significantly alters the ionic liquid structure, in particular, in the cation-cation interactions, in agreement with the single-crystal structure described recently (Holbrey, J. D.; Reichert, W. M.; Nieuwenhuyzen, M.; Sheppard, O.; Hardacre, C.; Rogers, R. D. Chem. Commun. 2003, 476). In each case, the data was analyzed using an empirical potential structure refinement process.

Aggregation of Imidazolium Ionic Liquids in Molecular Liquids Studied by Small-Angle Neutron Scattering and NMR

“…Results reveal that the heterogeneity of the mixture rises at xC6D6 = 0.7 because the mole fraction is close to the limit of the solubility. As shown in the previous investigations on mixtures of imidazolium-based ILs and benzene, [30][31][32][33] the benzene molecules interact with the imidazolium rings by the p-p interaction. In addition, the crystal structure of EMI + TFSA --benzene mixtures previously reported has shown some hydrogen bonds between the oxygen atoms of TFSA -and the hydrogens of benzene molecule.…”

“…30 Thus, benzene molecules will not be easily accepted into EMI + TFSAbeyond the molar ratio of IL to benzene 1:2, which corresponds to xC6D6 = 0.67.…”

Excess molar volumes and viscosity behaviour of binary mixtures of aniline/or N,N-dimethylaniline with imidazolium ionic liquids having triflate or bistriflamide anion

“…On the other hand, ionic liquids reveal very interesting fundamental features: i) they have specific structure represented by polar (ionic) and non-polar (aliphatic) domains [4], which is crucial for the aforementioned diverse solvent power and ii) they allow a variety of interactions in their mixtures: dispersion forces between aliphatic chains present in the mixtures of imidazolium ionic liquids with alcohols [15]; strong interactions such as ionic (Coulomb forces [16] and ion-dipole interactions [17]), hydrogen bonds [15,[18][19][20], and specific interactions with the aromatic compounds [21][22][23].…”

Solvation in aqueous binary mixtures: consequences of the hydrophobic character of the ionic liquids and the solvatochromic probes

“…This discussion is based on the nature of probe-IL interactions, including: weak hydrogen bonding between the CH 2 groups of the IL side chain and the p-electron system of the probe; 30 electrostatic interactions between the IL cation and the probe p-electron system, as indicated from the data of solubilization of aromatic compounds in ILs, 31 and neutron scattering studies on benzene-IL binary mixtures; 32 the interactions of the ions of the IL with each other and with water, as revealed by calorimetric studies of IL-water mixtures. 33 An example of point (a) above is the dependence of both j (IL-W/IL) and j (IL-W/W) for OcPMBr 2 on the hydrophobicity of the IL.…”