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A series of solutions composed of air- and water-stable hydrophobic ionic liquids (ILs) [Etpy][Tf2N], [Bupy][Tf2N], [Pepy][Tf2N], [EtM4py][Tf2N], and [BuM4py][Tf2N] were prepared. The electrical conductivity of the solutions was investigated at T= 298.15 K, respectively. Then the electrical conductivity of solutions of [Bupy][Tf2N] and [Hepy][Tf2N] in acetonitrile/propylene carbonate were investigated at temperature range from (283.15 to 313.15) K. The correlation of concentration and electrical conductivity was fitted according to the empirical Casteel–Amis (CA) equation. The maximum electrical conductivity was extrapolated by the fitted result. The influence of the successive methylene (−CH2−) group and the organic solvent to the electrical conductivity was discussed. The temperature dependence of the electrical conductivity of the solutions, ILs [Bupy][Tf2N] and [Hepy][Tf2N] in acetonitrile/propylene carbonate, was fitted by the empirical Vogel–Fulcher–Tamman (VFT) equation at a volume ratio of 50 %. [ABSTRACT FROM AUTHOR]

Solution densities and conductivities for solutions of [Cnmim]Br (n= 8, 10, 12) ionic liquids (ILs) in ethylene glycol, N,N-dimethylformamide, and dimethylsulfoxide have been determined at 298.15 K as a function of ionic liquid concentration. The apparent molar volumes, standard partial molar volumes, molar conductivities, and the limiting molar conductivities of the ILs have been derived from the experimental data. On the basis of the values of the standard partial molar volume and the limiting molar conductivity of the Br−anion available in the literature, the standard partial molar volumes and the limiting molar conductivities for the cations have also been reported in the three organic solvents. These data help to examine the effect of alkyl chain length of the cations and properties of the solvents. It was shown that the standard partial molar volumes of the ILs and their cations increased, but the limiting molar conductivities decreased linearly with the increase of the alkyl chain length. The fluidity of the solvents played an important role in the conductivity properties. [ABSTRACT FROM AUTHOR]