Effect of hydration on intermolecular interactions in tetrabutylammonium chloride based deep eutectic solvents

The high viscosity of deep eutectic solvents (DESs) restricts their applications in various fields, which can be overcome by the addition of water. The knowledge of the new interactions arising between the com-ponents of DES and water in their mixtures is important for the understanding of the changes in their liquid structures. Molecular dynamics simulations have been carried out on two hydrated DESs based on tetrabutylammonium chloride at three different concentrations, to gain atomic-level insights into the structural changes. Intermolecular interactions in the DESs are influenced by the addition of water due to the preferential solvation of anions. Water forms hydrogen bonds with DES components and has the most significant interaction with the anion, which is evident from the radial and spatial distribu-tion functions. Mean squared displacements and self-diffusion coefficients of the components of the DES increase with the hydration level due to the decrease in the interactions between the constituents of DES. The reduction in the intensity of the peak in structure factor also signifies the effect of water on long-range interactions.(c) 2022 Elsevier B.V. All rights reserved.