Thermodynamic characterization of the liquid-liquid extraction of silver by acyclic dithia benzene derivatives

A study of the liquid-liquid extraction equilibria between aqueous Ag(I) and 1,3-bis[(ethylthio)methyl]benzene, 1,3-bis[(pentylthio)methyl]benzene and 1,3-bis[(octylthio)methyl]benzene in chloroform solution, is reported.The results have been expressed in terms of solvent extraction reactions between Ag(I) in aqueous solution and the ligands in the organic phase.A numerical analysis of the metal distribution data has determined the following reactions to be responsible for the extraction process in all cases:Ag++L(org)+NO-3→[LAg(NO3)](org)Ag++2L(org)+NO-3→[L2Ag(NO3)](org)From this analysis polynuclear species have also been found to be formed in the aqueous phase. Thus, trinuclear species [L3Ag3(NO3)3] were found to give the best interpretation of the experimental data. Copyright (C) 1998 Elsevier Science B.V.