Rational eutectic solvent design by linking regular solution theory with QSAR modelling

Although eutectic solvents (ES), also widely termed as deep eutectic solvents (DES), have attracted significant interest in various chemical processes, the rational design of them remains challenging due to the difficulty in estimating eutectic formation. In this work, the regular solution theory (RST) and quantitative structure-activity relationship (QSAR) modelling are linked to the design of ES. The RST method meriting simplicity and solid physical basis is systematically examined for correlating the solid-liquid equilibria of 99 ES systems collected from literature. The QSAR model between the RST interaction parameters of these ES systems and the molecular descriptors of their constitutive components is developed through elaborate descriptor selection. With the final QSAR model based on 14 molecular descriptors, the eutectic temperature (T-e) and composition (x(e)) of ES systems can be accurately predicted with mean absolute deviations of 13.89 K and 0.0973, respectively. The eutectic formation of novel component combinations can be readily predicted, thereby allowing novel ES design. As an example, from the combinations of all involved components in the collected database, 186 novel ES systems are identified and 99 of them are estimated to present as liquid under room temperature. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, regular solution theory and quantitative structure-activity relationship modelling were used for the design of eutectic solvents. Through the development of a QSAR model based on the RST interaction parameters and molecular descriptors, the eutectic temperature and composition of eutectic solvent systems could be accurately predicted, allowing for the design of novel eutectic solvents.