Dimer of Diruthenium Compound Bridged by 1,1′-Diethynylferrocene: Ferrocene as a Weak Mediator for Electronic Coupling

The reaction between Ru2(ap)4Cl (ap = 2-anilinopyridinate) and lithiated 1,1′-diethynylferrocene resulted in the expected product 1,1′-[Ru2(ap)4(CC)]2Fc (1) and 1-(Me3SiCC),1′-[Ru2(ap)4(CC)]Fc (2) as a byproduct. X-ray diffraction study of compound 1 revealed an anti arrangement of two Ru2(ap)4(σ-CC) fragments around the Fc unit. Cyclic and differential pulse volatmmetric (CV and DPV) measurements indicated that two Ru2 termini in 1 are weakly coupled in the reduced form. Also reported is the MO analysis of coupling mechanism based on the extended Hückel calculation of 1.