2. Properties of ionic liquids and initial applications

2.1 Structure and physico-chemical properties of ionic liquids

Ionic liquids have exciting physico-chemical properties. In essence, ionic liquids are salts, i.e. polar compounds. They dissolve numerous organic and inorganic compounds, and readily stabilize charged or polar solutes. Their physico-chemical properties depend on the nature and size of the two ions. Ionic liquids with chloride, bromide or trifluoroacetate anions are miscible with water (hydrophilic), whereas when the anion is a hexafluorophosphate or a bis-(trifluoromethanesulfonyl)-imide ${\text{NTf}}_2^{-}$ , solubility in water is very limited (hydrophobic). Thus, the...