CALIXARENES DERIVATIZED WITH SULFUR-CONTAINING FUNCTIONALITIES AS SELECTIVE EXTRACTANTS FOR HEAVY AND PRECIOUS-METAL IONS

The calix[4]arenes tyl-25,26,27,28-(2-methylthioethoxy)calix[4]arene, 25,26,27,28-(2-methylthioethoxy)calix[4]arene; and ,27,28-(2-(2-thioph enecarboxy)ethoxy)calix[4]arene have been prepared. The structure of 2 5,26,27,28-(2-methylthioethoxy)calix [4] arene has been verified by X- ray crystallography, The crystals with the empirical formula C40H48O4S 4 are monoclinic C2/c with a = 20.428(2) Angstrom, b = 10.581(1) Angst rom, c = 20.445(2) Angstrom, beta = 118.461(5)degrees, Z = 4. These ca lix[4]arenes are effective extractants for transferring heavy metal io ns from aqueous solution into chloroform. The extraction of Sn(II), Hg (II), Ag(I), pd(II), Au(III), MeHg(II), Pb(II) and Cd(II) into chlorof orm with these calix[4]arenes is compared with that performed with 2-N ,N-dimethyldithiocarbamoylethoxy)calix[4]arene, 2-N,N-dimethyIdithioca rbamoylethoxy)calix[4]arene, and butyl-25,26,27,28-(2-mercaptoethoxy)c alix[4]arene.