Ionic Liquids and Dense Carbon Dioxide: A Beneficial Biphasic System for Catalysis

Increasing ecological concerns alongside with economical considerations have triggered research into greener catalytic applications for quite some time. The potential number of ILs is tremendous, and thus testing all the properties of all ILs would be a preposterous task to complete. A more useful approach is to develop models to understand ILs and anticipate the correct experiments to perform. Many models are under development, and the dilemma is often the balance between the simplicity and the accuracy of the model. Due to their structural diversity, ILs have many possibilities for specific interactions on a molecular level, including Coulomb interactions and hydrogen bonds. Using ILs as solvents for chemical reactions leads to the same challenges concerning product recovery as encountered in classical solvent applications. Extractions with water work only for hydrophilic products, and under the condition that the IL is not miscible with water.