Silyl derivatives of ferrocene with pending indenyl or fluorenyl substituents at silicon

The reactions of chlorosilyl-substituted ferrocenes with indenyl lithium and fluorenyl lithium have been used to synthesise new ferrocene derivatives in which 1-indenyl (ind) or 9-fluorenyl (flu) substituents are connected with the ferrocene sandwich through a silicon bridge. In addition to the monosubstituted indenyl-silyl- and fluorenyl-silyl-ferrocenes FcSiMe2(ind) (1a), FcSiMe2(flu) (1b), FcSiMe(Ph)(flu) (2b), FcSiMe(flu)2 (3b) and FcSiCl(flu)2 (4b), the 1,1′-disubstituted ferrocenes fc[SiMe2(ind)]2 (5a) and fc[SiMe2(flu)]2 (5b) as well as the 1-sila-[1]ferrocenophanes fc[SiMe(ind)] (6a) and fc[SiMe(flu)] (6b) were included in this study. The products were characterised in solution by 1H-, 13C- and 29Si-NMR spectroscopy and by mass spectrometry. The molecular structures of the di(fluorenyl)silyl ferrocenes 3b and 4b and of the 1-sila-[1]ferrocenophanes 6a and 6b were determined by single crystal X-ray crystallography.