A novel approach to the elucidation of facilitated ion transfer mechanisms at the liquid/liquid interface

The modification of the water/organic interface with size-selective membranes is presented as a means to elucidate the mechanism of facilitated ion transfer processes. In particular, an interfacial or organic phase complexation reaction is observed for the transfer of Cu2+ ions facilitated by dibenzo-18-crown-6, whereas the complexation process for the 1,4,7,10-tetrathiacyclododecane facilitated transfer of the same ion is suggested to occur within the aqueous phase. The contrasting transfer mechanism is discussed in terms of the solution phase behaviour of the thio-ether ligand. (C) 2004 Elsevier B.V. All rights reserved.