Tenfold Metalation of Ferrocene: Synthesis, Structures, and Metallophilic Interactions in FeC(10)(HgX)(10)

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O(2)CC(3)H(7))(2) in a facile one‐pot reaction in multi‐gram scale and high yields. The butyrate groups in FeC(10)(HgX)(10) (X=O(2)CC(3)H(7)) can be exchanged by treatment with trifluoro‐ or trichloroacetic acid (X=O(2)CCF(3), O(2)CCCl(3)). Substitution of the trifluoroacetate groups by halides (X=Cl, F) proceeds easily in aqueous THF. The completeness of metalation was confirmed by NMR and vibrational spectroscopy, mass spectrometry, as well as elemental analysis. Additionally, the first crystal structures of permetallated metallocenes are presented: FeC(10)(HgX)(10) (X=Cl, O(2)CCF(3), O(2)CCCl(3)).