Synthesis and Structures of Triple-Decker Complexes with a Bridging Tetramethylcyclopentadienyl Ligand

New triple-decker complexes with bridging tetramethylcyclopentadienyl ligands were synthesized by the reaction of electrophilic metal fragments with octamethylferrocene, Cp-2'Fe (Cp' = C5Me4H). The reaction of coordinatively unsaturated ruthenium cations [(C5R5)Ru](+) (R = H, CH3) with Cp-2'Fe afforded purple-colored heterometallic triple-decker complexes [(C5R5)Ru(mu-Cp')-FeCp'](+) by direct electrophilic addition. Surprisingly, the analogous reaction with the coordinatively unsaturated manganese cation [Mn(CO)(3)](+) and Cp-2'Fe produced a blue homometallic triple-decker complex, [Cp'Fe(mu-Cp')FeCp'](+), by ring abstraction and subsequent addition of the newly generated cation [Cp'Fe] to an equivalent of Cp-2'Fe. Three air-stable triple-decker complexes, [Cp'Fe(mu-Cp')FeCp'](+) (2), [CpRu(mu-Cp')FeCp'](+) (3), and [Cp*Ru(mu-Cp')FeCp'](+)(4), have been characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction.