Thiol and dithioether derivatives of tripodal extraction reagents have been newly prepared and employed to investigate the extraction behavior of precious metals. Both sulfur-containing compounds did not exhibit a pH dependency for precious metal extraction. The thiol type derivative exhibited a high extraction ability for gold(III), silver and palladium(II), and a 1 : 3 (extractant : metal) stoichiometry for gold(III) and silver.The results showed that the thiol derivative exhibited little structural effect due to the strong functionality of thiol group. The dithioether derivative also extracted gold(III), silver and palladium(II), however the silver extraction is caused by the structural effect of the tripodal framework, while gold(III) and palladium(II) extraction is probably attributed to a partial structural effect. The tripodal derivative possesses a high extraction ability compared with the corresponding monopodal compound. Tripodal and monopodal derivatives showed 1 : 1 and 1 : 2 (extractant : metal) stoichiometry for silver. This means that the tripodal derivative exhibited the structural effect as a size effect, converging effect of the multi functionality, complementary effect. The coordination site of the tripodal derivative was confirmed by 1 H-NMR spectra before and after the silver loading. Stripping of the loaded silver from the tripodal derivative was also investigated. Finally, the stepwise separation of silver and palladium(II) was carried out and roughly achieved by using different eluents.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.