Synthesis and properties of homoannularly- and heteroannularly carbonyl-bridged binuclear ruthenocene derivatives

1-Carboxyl-1′,2′,3′,4′,5′-pentamethylruthenocene was heated with (CF3CO)2O overnight at 90 °C to give anti-8,9,10,11,12,20,21,22,23,24-decamethyl[1.1](2,18)(6,14)ruthenocenophan-1,13-dione in 52% yield, whose structure was determined by X-ray diffraction (XRD). Chlorocarbonylruthenocene was treated with anhydrous aluminum chloride in refluxing dichloroethane to give anti-[1.1](2,18)(6,14)ruthenocenophan-1,13-dione and [1,1](2,20)(6,14)ruthenocenophan-1,13-dione, although, with a tiny yield (3%). In the protonated species of two homoannularly bridged ruthenocenophanes the positive charge was partially delocalized. The structure of the protonated species was determined by XRD. [1,1](2,20)(6,14)Ruthenocenophan-1,13-dione was fluxional and the activation energy (ΔG≠=56.5 kJ mol−1) of the dynamic process was determined by the VT-method.