A Computational Study on Choline Benzoate and Choline Salicylate Ionic Liquids in the Pure State and After CO2 Adsorption

Choline-based ionic liquids show very adequate environmental, toxicological, and economical profiles for their application in many different technological areas. We report in this work a computational study on the properties of choline benzoate and choline salicylate ionic liquids, as representatives of this family of compounds, in the pure state and after CO2 adsorption. Quantum chemistry calculations using the density functional theory approach for ionic pairs and ions, CO2 pairs, were carried out, and the results analyzed using natural bond orbital and atoms in a molecule approaches. Classical molecular dynamics simulations of ionic liquids were done as a function of pressure, temperature, and CO2 concentration. Microscopic structuring and intermolecular forces are analyzed together with the dynamic behavior of the studied fluids.