Use of 8-sulfonamidoquinoline derivatives as chelate extraction reagents in ionic liquid extraction system.

Possible use of 8-sulfonamidoquinoline derivatives as chelate extraction reagents for solvent extraction of several divalent metal cations using an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]) as extraction phase was investigated as fundamental approach to develop novel extraction reagents for ionic liquid extraction system. The studied reagents were able to be used as extractants for the metal cations in the [bmim][PF(6)] extraction system. Furthermore, their extractability in the [bmim][PF(6)] system was superior to that in chloroform system. Most of the extracted species were (hydrated) neutral complexes, whereas, in use of the derivative having trifluoromethyl group, Cd(2+) was extracted as anionic complex accompanied with anion-exchange process.