Electrosynthesis, physico-chemical and electrocatalytic properties of a novel electroactive Ru(0) material based on the (Ru(terpy)(CO)) frame (terpy=2,2′:6′,2′′-terpyridine)

International audienceThe preparation of an electroactive material based on a (Ru(terpy)(CO)) frame (terpy/2,2?:6?,2??-terpyridine) has been achievedby the two electron reduction of trans- or cis-[Ru(terpy)(CO)Cl2] complexes. During this electrochemical process, two chlorideligands are released and metal/metal bonds are formed. The highly coloured resulting compound containing Ru/Ru bonds caneither be coated as a film on an electrode surface in acetonitrile electrolyte or generated as a soluble product in DMSO electrolyte.The nature of this material does not depend on the stereochemistry of the starting complex and its characterization, either as a solidand in solution, has been investigated by an interplay between electroanalytical and spectroscopic techniques including 1H-NMR,UV/vis, MS and IR. It appears from the data that one of the possible structure of the material is an oligomeric [Ru(terpy)(CO)]nwith n/3. The trans- and cis-[Ru(terpy)(CO)Cl2] complexes and the related organometallic metal/metal based material displaycatalytic activity in the electroreduction of carbon dioxide in hydro-organic media. Interestingly, [Ru(terpy)(CO)]n modifiedelectrodes also display electrocatalytic activity in purely aqueous solutions