Removal of metal ions from aqueous solutions using chelating task-specific ionic liquids

A new class of imidazolium salts with appended aminodiacetic acid moieties as di-tert-butyl esters has been synthesized. An improved synthetic route compared to that previously reported is described. These task specific ionic liquids have been used for the formation of metal chelates with Cu(II), Ni(II) and Co(II) in aqueous solutions. The hydrophobicity and solubility of these metal complexes has been fine-tuned by changing the properties of the imidazolium salts from which they are derived through the introduction of alkyl chains onto the imidazolium core.