Cyclic transport of Fe3+ As H[FeCl4] and H[FeBr4] through a dibutyl ether-benzene membrane

Cyclic transport of Fe³⁺ as HFeX₄], where X is Cl or Br, across solvent-type liquid membranes has been demonstrated. HFeCl₄] was transported from HCl into HBr across a dibutyl ether—benzene mixture. In HBr the transported species reacted to HFeBr₄], which moved out to the HCl side against the concentration gradient of Fe³⁺. On the HCl side it was reconverted into HFeCl₄]. This continued till equilibrium was achieved. Likewise, Fe³⁺, present as HFeBr₄] in HBr, migrated from HBr into HCl and then back to HBr across the same membrane.