Modulation of internuclear communication in multinuclear Ruthenium(II) polypyridyl complexes

The synthesis and characterization of dinuclear ruthenium polypyridyl complexes based on the bridging ligands 1,3-bis-(5’-(pyridin-2’’-yl)-1’H-1’,2’,4’-triaz-3’-yl)-benzene, 1,4-bis-(5’-(pyridin-2’’-yl)-1’H-1’,2’,4’-triaz-3’-yl)-benzene, 2,5-bis-(5’-(pyridin-2’’yl)-1’H-1’,2’,4’-triaz-3’-yl)-thiophene, 2,5-bis-(5’-(pyrazin-2’’-yl)-1’H-1’,2’,4’-triaz3’-yl)-thiophene, and of their mononuclear analogues are reported. Electrochemical studies indicate that in these systems, the ground state interaction is found to be critically dependent on the nature of the bridging ligand and its protonation state with strong and weak interactions being observed for thienyl and phenyl linked complexes respectively.