Ditopic, flexible hydrazone-based building blocks with pendant 2,2′:6′,2′′-terpyridine metal-binding domains

The synthesis and characterization of three new bis(2,2′:6′,2′′-terpyridine) (tpy) ligands containing different hydrazone spacers between the metal-binding domains are reported, and their ability to act as bridging ligands has been illustrated by the formation of [(tpy)Ru(μ-1)Ru(tpy)]4+ where 1 is 1,4-benzenedicarbaldehyde bis(2,2′:6′,2′′-terpyridin-4′-ylhydrazone) . The single crystal structure of [(tpy)Ru(μ-1)Ru(tpy)][PF6]4·8MeCN is described.