RuII Complexes of Bis(1,10‐phenanthrolin‐2‐yl)diazines

A series of three bis‐tridentate bridging ligands has been prepared in which two 1,10‐phenanthroline units have been symmetrically appended to a central pyridazine, pyrimidine, or pyrazine ring. These ligands have been treated with [Ru(tpy‐d11)Cl3] to afford both mono‐ and dinuclear complexes whose photo‐ and electrochemical properties have been evaluated (tpy = 2,2′:6′,2′′‐terpyridine). A structural comparison is made between [(tpy)Ru(3)Ru(tpy)](PF6)4 and a previously reported complex involving 2,2′‐bipyridines in place of phenanthrolines on the bridging ligand and surprisingly little difference is found. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)