Theoretical study of physicochemical properties of selected ammonium salt-based deep eutectic solvents

Binary deep eutectic solvents (DESs) were computationally (in-silico) designed by combining three quaternary ammonium salts, namely tetramethylammonium chloride (TMAC), choline chlorine (ChCl) and betaine as hydrogen-bond acceptors (HBAs) with sorbitol, glycerol, urea, ethylene glycol, glucose, acetic-acid, caffeic acid and 1,2-butanediol as hydrogen-bond donors (HBDs). The chosen components are among the most that were reported in the literature. Preparation of DESs with high stability relies on the interaction mechanisms between the HBAs and HBDs within the DES. In this work, interaction energies were calculated by means of COnductor-like Screening MOdel for Real Solvents (COSMO-RS) theory, which was also used to calculate σ–profiles and σ–potentials. The charge density, Fukui indices, reactivity and combination mechanisms were predicted using Dmol3 module (Materials Studio) for each component and the resulting DESs. COSMOthermX functions were used in calculating the physicochemical properties of the designed DESs. Comparison of the calculated properties is expected to provide satisfactory information about the stability and performance of the chosen deep eutectic solvents. In general, there was a relatively good agreement between the predicted values of physicochemical properties and those reported in the literature.