Experimental and theoretical study of the physicochemical properties of the novel imidazole-based eutectic solvent

Novel solvents and their applications are experiencing an increasing interest by the scientific community. Imidazole has been utilized as a major component in many successful ionic liquids. However, very limited studies were reported for using it as a hydrogen bond acceptor in the synthesis of eutectic solvents. In this work, a novel eutectic solvent composed of Imidazole and Monoethanolamine (MEA) is synthesized at different molar ratios. The basic physicochemical properties such as melting point, density, viscosity, and refractive index were measured at different temperatures and modeled as a function of molar composition and temperature. FTIR and H-1 NMR analyses were conducted and, the nature and strength of the molecular interaction between the two solvent molecules were investigated by conducting combined molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The study revealed the electrostatic H-bonding nature of interaction with strength related to their bond distances. The binding energy between the two DES ingredients is proportional to the amount of MEA in the DES due to increasing the H-bonding interactions between Imidazole and MEA molecules. These findings suggest that DES might be used in a variety of chemical and industrial applications.