M. khoshalhan - Department of Chemistry,University of Mohaghegh Ardabili, Ardabil, Iran
H. Shekaari - Department of Physical Chemistry,University of Tabriz, Tabriz Iran
A. Bezaatpour - Department of Chemistry,University of Mohaghegh Ardabili, Ardabil, Iran

In this work, we present our results on density measurements of 1- alkyl -3- methylimidazolium bromide ([RMIm]Br R = propyl(C3), pentyl(C5), hexyl(C6))+ N4-Type-Schiff base + acetonitrile ternary mixtures at atmospheric pressure. The standard partial molar volumes the studied mixtures have been calculated using these experimental data and used to interpretation of various solute-solvent interactions occurring between components of solution. The experimental density, d, values as function of ionic liquid concentration, m, for mixtures, [RMIm]Br + N4-Type-Schiff base + acetonitrile ternary mixtures at T = 298.15K. The apparent molar volumes, V of [RMIm]Br were calculated from the densities of the solutions using the following equation: (فرمول در متن اصلی مقاله) where m is molality of [RMIm]Br in N4-Type-Schiff base+ acetonitrile solutions, d and d are densities of the solutions and pure solvent, respectively, M is molar mass of [RMIm]Br. The standard partial molar volumes of the [RMIm]Br,V 0  were calculated by the least-squares method through the fitting of the following equation [3] (فرمول در متن اصلی مقاله) The results show that the values of V0 for [RMIm]Br increase with increasing alkyl chain length of ionic liquids. These results suggest that addition chain length of ionic liquids in MeCN solutions implies that more stronger interaction between solute-solvent (MeCN and [RMIm]Br) and leads to more release of solvent molecules to the bulk.