Metal complexes that transport electrons across liquid membranes

Lipophilic metal complexes (displaying 1-electron redox activity) are used as carriers for the transport of electrons across bulk liq. membranes from an aq. reducing phase to an aq. oxidizing phase. The [FeIII,II(bpy)2]3=/2+ redox system (bpy = 4,4'-di-tert-butyl-2,2'-dipyridyl) transports electrons from both cationic and anionic aq. reducing agents to aq. Ce(IV) and counter-transports perchlorate ions in the opposite direction. Electron/chloride ion cross transport between aq. persulfate and aq. metal centered reducing agents, mediated by the membrane dissolved [NiII,IIILCl2]2+/3+ redox system (L = (N-cetylcyclam) takes place at a much higher rate. The overall transport rate in the 2 types of expts. controlled by that of the redox process occurring at the membrane/aq. reducing phase interface and is to be related to the type of mechanism (inner or outer sphere) by which the 2-phase electron transfer process takes place.