Synthesis, characterization, and properties of binuclear ruthenium complexes with dendritic side chains on their bridges

Three binuclear ruthenium complexes with dendritic side chains, 1,4-[RuCl(CO)(PMe3)3CHCH]2C6H2-2,5-(Gn)2 with Gn = G0 (1), G1 (2), and G2 (3), have been synthesized by the reactions of the corresponding diethynylaryls with the ruthenium hydride complex [RuHCl(CO)(PPh3)3] and subsequent ligand exchange with PMe3. The complexes have been characterized by elemental analysis, NMR, and UV–Vis spectrophotometry. The structure of complex 1 has been determined by X-ray crystallography. Their electrochemical properties have been investigated. Electrochemical studies in solution may imply that the two metal centers in complexes 1–3 have good electronic communications between each other. However, the electron communication is not effectively enhanced with increasing generation of the dendrons in solution.