Physicochemical Properties of the Binary Mixtures of CuII-Containing Chelate-Based Ionic Liquids with Linear Alcohols

Systematic measurements (densities, viscosities, conductivities) combined with small-angle X-ray scattering (SAXS) experiments were performed for binary mixtures of Cu-II-containing chelate-based ionic liquid (ChIL) with linear alcohols. The experimental results were explained by disruption of alcohols to ionic aggregation of the ChILs. Viscosity deviations (Delta eta) of four binary systems all show negative values, which is because the ion-dipole interactions between the alcohols and the imidazolium ring of the ChIL weakened the hydrogen bonding between cation and anion of ChIL, in turn leading to higher mobility of ions and the decreased viscosity. Excess molar volumes (V-E) of the binary mixtures for the ChIL with methanol/ethanol all exhibit V-shape deviation from that of ideal solution while S-shape from positive to negative values is observed with 1-propanol/1-butanol, which is because the short chain alcohols could enter into the interspace of the ChIL while it is difficult for long chain alcohols.