Redox Driven Intramolecular Anion Translocation Between a Metal Centre and a H bond Donating Compartment

Abstract: Dicationic ligands incorporating two 2,2’-bipyridine units and two imidazolium moieties, [1]2+ and [2]2+, form stable chelate complexes with CuII and CuI in acetonitrile solution. Each CuII complex binds two X ions according to two stepwise equilibria, the first involving the CuII centre and the second involving the bis-imidazolium compartment. CuI complexes are able to host only one NO3 ion in the bis-imidazolium cavity, while other anions induce demetallation. Thus, in the presence of one equivalent of NO3, the CuII/CuI redox change makes the anion translocate quickly and reversibly from one binding site to the other within the [CuII,I(1)]4+/3+ system, as demonstrated by cyclic voltammetry and controlled-potential electrolysis experiments.