The successive complex formation of trivalent lanthanide ions with ionophore ETH4120 at the liquid/liquid interface

Transfer of lanthanide ions across the liquid/liquid interface facilitated by ionopore ETH4120 has been studied by using cyclic voltammetry (CV) and chronopotentiometry with cyclic linear current-scanning (CPCLCS) under the condition where the concentration of ETH4120 in nitrobenzene was much smaller than the concentration of lanthanide ions in aqueous solution. One cathodic current peak (transfer from aqueous to nitrobenzene phase) and two anodic current waves (transfer from nitrobenzene to aqueous phase) were observed. The cathodic wave due to the formation of 1:1 (metal:ligand) complex and anodic waves showed successive formation of 1:2 and 1:3 complexes in nitrobenzene solution. But there was no cathodic wave corresponding to wave anodic waves. The ion transfer mechanism has also been discussed