Structure‐Determining CH…︁OSi Hydrogen Bonds in Cobaltocenium Fluoride Nonasil

Fixed in the SiO 2 cage at temperatures below 485 K , the [CoCp 2 ] + ion in the cobaltocenium fluoride nonasil 1 exhibits no rotational disorder. This unusual structural feature for clathrasils is attributed to strong CH…OSi interactions, among them hydrogen bonds with a H…O distance of 2.31 Å.\documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$$[{\rm CoCp_2}]^+{\rm F^{-}[SiO_2]_{22}}\quad{\bf 1}$$\end{document}