Linked C7 Carbon-Rich Bridges: A New Dimension for Ruthenium Redox-Active Organometallics

The synthesis of the tetrametallic complexes trans -[(Cl(dppe) 2 Ru═C═C═C(CH 3 )CH═C(−C≡C−Ru(dppe) 2 Cl)( p -C 6 H 4 )) 2 ][OTf] 2 ( 7b; dppe = 1,2-bis(diphenylphosphino)ethane) composed of two linked bimetallic units bearing a W-shaped C 7 carbon-rich bridge was achieved by modification of the unsaturated ligand precursor. This complex represents a novel example of the connection of two organometallic redox-active molecular wires via a carbon-rich chain for access to larger redox-active multicomponent assemblies. UV−visible and cyclic voltammetry studies show that the properties of the building blocks are retained in the new adduct, providing two conduits of approximately 12 Å for electron transfer in either an oxidation or a reduction process.