ELECTROCHEMICAL PROPERTIES AND ELECTROPOLYMERIZATION OF POLY(PYRIDINE) RHODIUM(III) COMPLEXES

Electrochemical characterization in organic electrolytes of a series of [Rh(III)(L)2Cl2]+ complexes containing 2,2'-bipyridine derivatives as ligands L is described. The re-oxidation of their doubly reduced form [Rh(I)(L)2]+ leads, on the cyclic voltammetry time-scale, to either the starting material or [Rh(III)(L)2(S)2]3+ (S = solvent) according to the coordinating properties of the solvent. Films of the corresponding polypyrroles are easily prepared by oxidative electropolymerization of complexes containing ligands substituted with pyrrole groups. Slow release and re-coordination of ligands (Cl- or solvent molecules) in the polymeric films are responsible for a greater irreversibility of the Rh(III)/Rh(I) redox system for complexes in their film form.