Synthesis and physicochemical properties of new tropine-based chiral dication ionic liquids

A new series of chiral dicationic ionic liquids (DILs) were successfully synthesized and characterized by IR and NMR. The density of the whole family of ILs was measured and related physical properties including thermal expansion coefficient, molecular volume, standard molar entropy, and crystal energy were estimated by theoretical methods. Moreover, the viscosity, conductivity of DILs and the binary mixtures of ionic liquid + water were determined. The data were correlated with Arrhenius equation and VogeL-Fulcher-Tamman (VFT) equation and the results were discussed subsequently. Furthermore, the molar conductivity, dissociation equilibrium constant and critical micelle concentration of DIL solution were deduced by experimental or theoretical methods. At last, the influences of the carbon chain of ILs and temperature on density, viscosity and conductivity were discussed.