Synthesis and properties of multi-nuclear ruthenium (II) complexes of bis(2,2′ -bibenzimidazole)

Conjugated metallopolymers in which metal sites are in electronic communication through a conjugated organic backbone have been attracting growing interest. Bis(2,2′-bibenzimidazole) has been prepared as the conjugated backbone. The multinuclear Ru complexes were synthesized by the complexation of the conjugated bis(2,2′-bibenzimidazole) with Ru(bpy)2Cl2. The deprotonation form of the dinuclear Ru complexes may show enhanced electron transport ability between metal centers through the conjugated bibenzimidazole backbones. Deprotonation also allows the synthesis of tetranuclear Ru complexes. The preparations, spectroscopic and electrochemical properties of these multinuclear Ru complexes were investigated.