Influence of anion on thermophysical properties of ionic liquids with polar solvent

In this work, we have reported a series of ionic liquids (ILs) involving a common cation trimethyl ammonium, ([(CH3)3NH]+), with generally used anions (acetate, [CH3COO]−, sulfate, [HSO4]−, phosphate, [H2PO4]−). To address the molecular interactions between the relatively new class of solvents such as trimethylammonium acetate [(CH3)3NH+] [CH3COO–] (TMAA), trimethylammonium hydrogen sulfate [(CH3)3NH+][HSO4−] (TMAS), and trimethylammonium dihydrogen phosphate [(CH3)3NH+][H2PO4–] (TMAP), with the polar solvent, dimethylsulfoxide (DMSO), the density (ρ), speed of sound (u) and viscosity (η) values have been measured over complete concentration range and wide temperature range from 298.15 K to 313.15 K in steps of 5 K under ambient pressure. By using these experimental results, excess volumes (VE), isentropic compressibility deviations (Δκs) and viscosity deviations (Δη) were obtained for all these binary systems at all experimental temperatures. The results are correlated by the Redlich−Kister type function to derive the coefficients and estimate the standard error. Further, the results for observed anion dependent phenomena and temperature influence on measured and derived properties are also discussed.

► We have reported a series of ionic liquids (ILs) involving a common cation. ► The molecular interactions between ILs and DMSO. ► The results for observed anion dependent phenomena. ► Redlich–Kister polynomial was used to correlate the results. ► The intermolecular interactions were analyzed on the basis of properties.