Ionic liquids - the combinatorial challenge

Ambient temperature ionic liquids possess a remarkable range of desirable intrinsic characteristics, namely, negligible vapour pressure, wide liquidus range, thermal stability, high ionic conductivity and a wide electrochemical window. Their exploitation as catalysts, selective material-extraction media, liquid crystals, electrochemical process media, and solvents is in its infancy, especially as clean technology candidates [1]. The archetypal systems for homogeneous catalytic exploration are 1-ethyl-3-methylimidazolium chloride — aluminium(III) chloride, [emim]Cl-AlCl3 and 1-butylpyridinium chloride — aluminium(III) chloride, [Bupy]Cl-AlCl3 [2]. However, other water and/or air-stable ionic liquids [3] have been reported as catalytically active [4].