Extraction Behavior of Divalent Metal Cations with 2-Mercaptopyridine N-Oxide in Ionic Liquid Chelate Extraction

摘要

The possible use of 2-Mercaptopyridine N -oxide (HSPyO) as an extractant in ionic liquid chelate extraction was investigated with using several divalent metals (M~(2+), M = Cu, Ni, Zn, Cd and Mn). The extraction performance of HSPyO in the 1-buthyl-3-methyimidazolium bis(trifluoromethanesulfonyl)imide (C_(4)mimTf_(2)N) system was very similar to that in the chloroform system, except for Cd~(2+). Over wide pH range, Cu~(2+), Ni~(2+) and Zn~(2+) were extracted quantitatively into C_(4)mimTf_(2)N as neutral 1:2 complexes M(SPyO)_(2). Furthermore, the strange extraction behavior for Cd~(2+) into C_(4)mimTf_(2)N was found to originate in the competitive extraction of neutral Cd(SPyO)_(2) and anionic Cd(SPyO)_(3)~( – ).