Extractive and sorption preconcentration of rhenium(VII) ions with the use of bis(diphenylphosphoryl)-substituted aza podand

Abstract

Interfacial distribution of trace amounts of ReO4− ions between aqueous solutions of mineral acids and solutions of diphosphoryl-substituted aza podand [Ph2P(O)CH2CH2OCH2CH2]2NBu (I) in dichloroethane was studied. The stoichiometry of extracted complexes was determined, the influence of HClO4, HNO3, HCl, and H2SO4 concentration in aqueous phase and the nature of organic solvent on the efficiency of transition of ReO4− ions into organic phase was considered. Aza podand I shows larger extraction ability toward Re(VII) than monophosphorylated amines. The possibility of selective extraction and preconcentration of ReO4− ions by a complex-forming sorbent obtained by the noncovalent binding of compound I on the surface of carbon nanotubes was shown.