Ionic liquids (!Ls) are organic salts that are liquids at temperatures below 373. 15 K. They have received considerable attention as alternatives to the traditional organic solvents. Due to the phenomenal growth of publications dealing with their interesting physical and chemical properties and possible applications they have been attracting intense interest in the scientific literature. In solution, the solvation and ionic association of ILs detennine the unique properties of these systems and also most of the applications of !Ls are closely related to these phenomena occurred in the IL solutions. In addition, a fundamental issue in the design of novel ionic liquids is the understanding of the nature/strength of cation-anion interactions and intermolecular forces in the bulk ionic fluid due to their intrinsic relation with most of their physicochemical properties, such as melting temperature, density, viscosity, surface tension, and vapor pressure [1-3).
