The fine chemical industry has a major problem. When it makes a fine chemical, it produces large quantities of contaminated solvents. The recovery or disposal of this waste is expensive. The result is that industry is looking for cleaner technology.
Ionic liquids offer one solution.
They have no vapour pressure so volatile compounds can be removed by vacuum. They are outstandingly good solvents for a wide variety of compounds. They are relatively cheap and easy to prepare. Ionic solvents are not just an innocent medium for a reaction, but frequently modify the properties of reagents. Thus when HCl is dissolved in this ionic solvent, the Cl - is removed and the HCl becomes a much stronger acid, see G.P. Smith, A.S. Dworkin, R.M. Pagni, and S.P. Zingg, J. Am.