EXTRACTION BEHAVIOR OF SILVER ION WITH OPEN-CHAIN S,S'-ALPHA,OMEGA-ALKANEDIYL O,O'-BIS[2-(ETHYLTHIO)ETHYL]DITHIOCARBONATES

The S,S'-alpha,omega-alkanediyl O,O'-bis[2-(ethylthio)ethyl]dithiocarb onates, which are easily accessible by synthesis, have been used in so lvent extraction studies of precious metal ions. Taking S,S'-1,3-propa nediyl O,O'-bis[2-(ethylthio)ethyl]-dithiocarbonate (PbETEdTC) as the representative of this group, the compound appears to have promising e fficiency for the extraction of silver from perchlorate media, where t he silver ion forms a 1:1 extractable complex with PbETEdTC. A quantit ative back-extraction process from the organic phase is possible with 5 M HCl. From extraction studies, PbETEdTC proved to be a good extract ant for silver in a perchlorate medium. The important role played by s tructural modifications of the bis(dithiocarbonate) molecule is eviden ced by the differences in the silver extractabilities and silver-ligan d stoichiometries.