A study of the molecular interactions between ammonium-based ionic liquids and N,N-dimethylacetamide

Abstract In this work, we report the molecular interactions of different cation alkyl chain lengths with same anion of ammonium-based ionic liquids (ILs) such as tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with N , N -dimethylacetamide (DMA) through thermophysical properties with varying the compositions of ILs at different temperatures from 25 to 40 °C under atmospheric pressure. Experimental densities ( ρ ), ultrasonic sound velocities ( u ), viscosities ( η ) and refractive indices ( n D ) of binary mixtures of ILs with DMA are measured over the wide composition range. The excess molar volumes ( V E ), deviation in isentropic compressibilities ( Δκ s ), deviation in viscosities ( Δη ) and deviation in refractive indices ( Δn D ) are calculated from experimental values and are correlated by Redlich-Kister polynomial equations. Consequently, V E values show that negative for small cation alkyl chain length of ammonium-based ILs as compared to large cation alkyl chain length of ILs. We have observed the strength of intermolecular interactions such as hydrogen bonding, ion-ion pair interactions and induced dipole interactions between the ions of ammonium-based ILs with DMA from obtained data. Thermophysical properties, however, possessed by these binary systems are exceedingly promising and predictable that these systems will find applications in chemical industry.