Palladium(II) extraction from concentrated chloride media: Reactions involving thioamide derivatives

ABSTRACT

This work focuses on the detailed study of the palladium(II) extraction reactions by N-methyl-N-phenyl-octanthioamide (MPHTA) and N-methyl-N-cyclohexyl-octanthioamide (MCHTA) in toluene, since their ability to efficiently and selectively recover Pd(II) from a wide range of HCl concentrations is already known. Equilibrium data are presented and discussed, and further complemented by information depicted from UV–visible and NMR spectra. The determined apparent molar volumes show that MPHTA is monomeric, and MCHTA exhibits a slight tendency to aggregate. The Pd(II) extraction reactions by MPHTA and MCHTA are equivalent until 4.5 M HCl, passing through the formation of inner-sphere complexes with the metal ion.

KEYWORDS:

• Hydrochloric acid
• liquid–liquid extraction reactions
• palladium(II)
• thioamide derivatives

Funding

The financial support for the work reported in this article has been kindly provided by “FCT – Fundação para a Ciência e a Tecnologia” (Lisbon, Portugal) under the project with the reference number UID/MULTI/00612/2013. The PhD grant offered to Osvaldo Ortet (SFRH/BD/78289/2011) is gratefully acknowledged.

Additional information

Funding

The financial support for the work reported in this article has been kindly provided by “FCT – Fundação para a Ciência e a Tecnologia” (Lisbon, Portugal) under the project with the reference number UID/MULTI/00612/2013. The PhD grant offered to Osvaldo Ortet (SFRH/BD/78289/2011) is gratefully acknowledged.