Synthesis and Binding Studies of a Novel Highly Selective Ag(I) Ligand

Abstract

Ligands bearing S-and N-donors are an important class of extractants with demonstrated efficiency and selectivity for Ag + extraction over metals with similar chemistries. However, the synthesis of some of these ligands can be complicated and low yielding. Here, we report the synthesis of a novel ligand -N-(2-((4vinylbenzyl)thio)ethyl)acetamide, over two simple steps and in a good yield. The extractant was observed to demonstrate excellent selectivity for Ag + , extracting only Ag + from an aqueous solution also containing Cu 2+ and Pb 2+ .Moderate extraction efficiencies of 36 % for Ag + and 0% each for Cu 2+ and Pb 2+ were observed. From mass spectrometry and proton NMR titration data, the extractant was found to form both the 1:1 and 1:2 (Ag + :ligand) complexes with Ag + indicating that ligand forms bent linear and tetrahedral coordination complexes with Ag + . Overall, the results indicate that the novel amide-based ligand is highly selective for Ag + removal from aqueous solutions containing Cu 2+ and Pb 2+ . These results indicate the ligand could be easily synthesized and applied for selective silver recovery from low grade ores.