Derivatized Calix[4]arenes as Selective Phase Transfer Extractants for Heavy Metal and Oxyion Salts

Abstract

Abstract Calix[4]arenes with 2-methylthioethoxy, 2-thiophenecarboxyethoxy, 2-N,N-dimethyl-dithiocarbamoylethoxy and 2-mercaptoethoxy groups on the lower rim, and with methanethiomethyl and N,N-dimethyldithiocarbamoylmethyl groups on the upper rim, have been used for the transfer of Sn(II), Hg(II), Ag(I), Pd(II), Au(III), Ni(II), Pt(II), MeHg(II), Pb(II) and Cd(II) from aqueous solution into chloroform. These compounds generally extract Hg(II), Ag(I), Au(III) and Pd(II), but not Ni(II), Pt(II), Pb(II) and Cd(II). A series of calix[4]arenes with amide and amine functionalities bound to the lower rim have been used as extractants for the anions HP4 2-, SeO4 2-, VO3 −, ReO4 −, CrO4 2- and MoO4 2-. The extraction data into chloroform from solutions having a pH of 0.85 and 7.0 generally show that the amines are better extractants than the amides, and that the former are most effective from acidic solutions.