Edwin C. Constable, Peter Harverson and Catherine E.Housecroft
In situ synthesis of the oxygen-linked dinucleating compound bis{4′-(2,2′∶6′,2″-terpyridinyl)} ether I by the reaction of ruthenium(II)-coordinated 4′-chloro-2,2′∶6′,2″-terpyridine ligands with 4′-hydroxy-2,2′∶6′,2″-terpyridine allowed the preparation of the mono- and di-nuclear complex ligands [(terpy)Ru(I)][PF6]2 and [(terpy)Ru(I)Ru(I)][PF6]2 in which I has one coordinated and one non-coordinated metal-binding domain. Subsequent reaction of these complex ligands with labile iron(II) or cobalt(II) salts allowed the preparation of the heterotri- and heteropenta-nuclear complexes [{(terpy)Ru(I)}2M][PF6]6 and [{(terpy)Ru(I)Ru(I)}2M][PF6]10 (M = Co or Fe). Spectroscopic and electrochemical studies on these novel topologically linear species are described.