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.