Comprehensive physicochemical evaluation of deep eutectic solvents: quantum-chemical calculations and electrochemical stability

Abstract

The focus of the investigation is physicochemical properties (electrical conductivity, electrochemical window) and theoretical study of stability of the formed deep eutectic solvents (DESs). Quantum-chemical calculations have been performed to predict the formation of solvents with higher stability. The reported results reveal a complete description of fluid’s characteristics which of the components is the most effective donor for creation hydrogen bond with hydrogen bond acceptor. Two DESs have been synthesized by using of choline chloride as hydrogen bond acceptors (HBAs) and Urea and Lactic acid as hydrogen bond donors (HBDs). Also, DES have been synthesized by using of Lactic acid as hydrogen bond acceptors (HBAs) and Sodium Acetate as hydrogen bond donors (HBDs). The electrical conductivity of deep eutectic solvents was measured and the width of electrochemical window was evaluated using cycling voltammetry depending on water content in the solvent (0–25%).