Alkali metal oligoether carboxylates - A new class of ionic liquids

Article abstract of DOI:10.1002/chem.200801806

A new group of ionic liquids (IL) based on small inorganic cations and oligoether carboxylate anions were synthesized. The physicochemical properties of the salts were also investigated, and possible reasons for the formation of ionic liquids with alkali metal ions were proposed. It was found that complexation of the alkali metal cations by their combined oligoether- carboxylate counter-ion was sufficient to generate room-temperature liquid salts. It was also found that the use of simple tri- and tetraalkylammonium instead of alkali metal ions could also yielded ionic liquids at ambient temperature that appear to display additional desirable properties such as low viscosity. The result also showed that the combination of the 2,5,8,1 l-tetraoxatridecan-13-oate (TOTO) anion with biological cations such as choline could also lead to the development of even greener ILs.