Functionalized phosphonium based ionic liquids: properties and application in metal extraction

Abstract

The extraction of Cu(II), Zn(II), Co(II), Ni(II) and Pb(II) from model aqueous solutions using phosphonium based ionic liquids as sole extraction agents has been explored. The hydrophobic trioctyl(4-vinylbenzyl) phosphonium chloride, [P_888(4-VB)]Cl, allows almost complete removal of Pb(II), Cu(II), Zn(II) without addition of HCl, while the extraction of Co(II) and Ni(II) was almost null. An efficient extraction (ca. 100%) of Pb(II), Cu(II) and Zn(II) was obtained using [P_888(4-VB)][NO₂].