Extraction Behavior of Silver Ion with Open-Chain S,S′-α,ω-Alkanediyl O,O′-Bis[2-(ethylthio)ethyl]dithiocarbonates

The S,S′-α,ω-alkanediyl O,O′-bis[2-(ethylthio)ethyl]dithiocarbonates, which are easily accessible by synthesis, have been used in solvent extraction studies of precious metal ions. Taking S,S′-1,3-propanediyl O,O′-bis[2-(ethylthio)ethyl]dithiocarbonate (PbETEdTC) as the representative of this group, the compound appears to have promising efficiency for the extraction of silver from perchlorate media, where the silver ion forms a 1 : 1 extractable complex with PbETEdTC. A quantitative back-extraction process from the organic phase is possible with 5 M HCl. From extraction studies, PbETEdTC proved to be a good extractant for silver in a perchlorate medium. The important role played by structural modifications of the bis(dithiocarbonate) molecule is evidenced by the differences in the silver extractabilities and silver-ligand stoichiometries.