Synthesis and Structure of [Fe(η5-C9Me6)(η5-C5H4)SiMe2]: A Mixed-Ring [1]Ferrocenophane

A new bridged ligand incorporating the hexamethylindenyl moiety has been synthesized and used to prepare the corresponding ansa ferrocene, [Fe(η5-C9Me6)(η5-C5H4)SiMe2], 10, which is the first mixed-ring [1]ferrocenophane to be structurally characterized. Comparison of the crystal structure of 10 with those of [Fe(η5-C5H4)2SiMe2], 1, and rac-[Fe(η5-C9Me6)2SiMe2], 5a, shows many structural features, such as the ring tilt of 17°, to be intermediate between those of the two model compounds, while the average Si−C(ipso) bond length is much closer to that in 5a.