INTRODUCTION

Ionic liquids (ILs) are a new class of materials with excellent physico-chemical and biological properties. They are composed entirely of ions and are liquids at ambient or far below ambient temperatures, a property required for many different solvents and materials. Deep eutectic solvents (DESs) contain large, nonsymmetric ions that have low lattice energy and hence low melting points. They are usually obtained by the complexation of a quaternary ammonium salt with a metal salt or hydrogen bond donor (HBD). Both ILs and DESs have emerged as potentially attractive “green” recyclable alternative to environmentally harmful organic solvents. They have been used as solvents or materials or both in different applications due to their unique properties.

There are millions of ILs and DES solvents/materials that can be designed and prepared by interchanging from thousands of cationic and anionic constituents. However, screening the potential ILs or DES for specific application needs the thorough knowledge of their chemistry, thermochemical and thermophysical properties. In recent years, Conductor-like Screening Model for Real Solvents (COSMO-RS) has emerged as a potential tool for the effective prediction of thermodynamics properties without any experimental investigations. In fact, it offers a novel computational pathway extending from quantum chemistry to fluid phase thermodynamics, enabling the use of modern quantum chemistry predictive tools. COSMO-RS speculates the activity coefficient at infinite dilution values of the associated species to estimate the capacity and selectivity of ILs and DES for solubility studies