Homogeneous liquid-liquid extraction of metal ions with non-fluorinated bis(2-ethylhexyl)phosphate ionic liquids having a lower critical solution temperature in combination with water.

Ionic liquids with an ether-functionalised cation and the bis(2-ethylhexyl)phosphate anion show thermomorphic behaviour in water, with a lower critical solution temperature. These ionic liquids are useful for homogeneous liquid-liquid extraction of first-row (3d) transition metals.