The reaction of AgBF4 and [Rh(COD)Cl]2 (COD=1,5‐cyclooctadiene) in presence of [NEt4][C5(CF3)5] afforded the fluorocarbon soluble complex [Rh(COD)(C5(CF3)5)] by salt metathesis. This complex represents the first example for a successful coordination of the weakly basic [C5(CF3)5]− ligand, since its first synthesis in 1980. In addition to [Rh(COD)(C5(CF3)5)] also the byproduct [Rh(COD)(C5(CF3)4H)] was isolated and fully characterized. Accompanying DFT studies showed that the interaction energy of the [C5(CF3)5]− ligand towards the 12‐electron fragment [Rh(COD)]+ is ≈70 kcal mol−1 lower in comparison to [C5(CH3)5]− due to reduced electrostatic interactions and weaker π‐donor properties of the ligand. The quantitative but reversible substitution of the [C5(CF3)5]− ligand by toluene, converting it into a weakly coordinating anion, experimentally proved the extraordinary weak bonding interaction.

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O2CC3H7)2 in a facile one‐pot reaction in multi‐gram scale and high yields. The butyrate groups in FeC10(HgX)10 (X=O2CC3H7) can be exchanged by treatment with trifluoro‐ or trichloroacetic acid (X=O2CCF3, O2CCCl3). 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: FeC10(HgX)10 (X=Cl, O2CCF3, O2CCCl3).

Several cationic rhodium(I) complexes [Rh(COD)L2][C5(CF3)5] have been synthesized through substitution of the weakly bound [C5(CF3)5]– ligand from [Rh(COD)(C5(CF3)5)], further emphasizing its unique reactivity. Besides acetonitrile, pyridine derivatives with varying degrees...

Die Reaktion zwischen AgBF 4 und [Rh-(COD)Cl] 2 (COD = 1,5-Cyclooctadien) in Gegenwart von [NEt 4 ][C 5 (CF 3 ) 5 ] ergab den perfluorcarbonlöslichen Komplex [Rh(COD)(C 5 (CF 3 ) 5 )] durch Salzmetathese. Dieser Komplex stellt das erste Beispiel für eine erfolgreiche Koordination des schwach basischen [C 5 (CF 3 ) 5 ] À -Liganden, seit dessen Erstsynthese im Jahr 1980 dar. Zusätzlich zu [Rh(COD)(C 5 (CF 3 ) 5 )] wurde das Nebenprodukt [Rh(COD)(C 5 (CF 3 ) 4 H)] isoliert und vollständig charakterisiert. Begleitende DFT-Rechnungen zeigen, dass die Interaktionsenergie des [C 5 (CF 3 ) 5 ] À -Liganden gegenüber dem 12-Elektronen [Rh(COD)] + -Fragment aufgrund verringerter elektrostatischer Interaktionen und einer schwächeren π-Donorfähigkeit um � 70 kcal mol À 1 im Vergleich zu [C 5 (CH 3 ) 5 ] À erniedrigt ist. Die quantitative, jedoch reversible Substitution des [C 5 (CF 3 ) 5 ] À -Liganden durch Toluol, die ihn in ein schwach koordinierendes Anion überführt, demonstriert experimentell die außergewöhnlich schwache Bindungssituation.

The incorporation of fluorinated substituents in cyclopentadienyl anions leads to distinct changes in the properties of the corresponding metal complexes, e.g., with regards to electrochemical properties or metal–ligand bonding energies. This review summarizes the synthetic challenges of the preparation and coordination of fluorinated cyclopentadienyl anions.1 Introduction2 Fluorinated Cyclopentadienyls3 Cyclopentadienyls with One CF3 Group4 Cyclopentadienyls with Four CF3 Groups5 Cyclopentadienyls with Five CF3 Groups6 Cyclopentadienyls with ‘Fluorous Ponytails’7 Cyclopentadienyls with C6F5 Groups8 Trends in Interaction Energies9 Conclusion

We report the preparation and structural characterization of the first persilylated metallocene via metalation of decabromoferrocene. Whereas Grignard conditions turned to be insufficient due to steric and electronic effects of the silyl groups causing a decreased nucleophilicity of the metalated intermediates, stepwise lithium-halogen exchange yields complex mixtures of polysilylated compounds FeC10DMSnH10−n (n = 10, 9, 8) including the targeted decasilylated ferrocene. Those mixtures were successfully separated allowing a systematic study on silylation effects on ferrocene by XRD, CV, NMR and UV/vis spectroscopy supported by DFT calculations. The findings were used to develop a high-yielding and preparative simple way to generate a perfunctionalized and overcrowded ferrocene, FeC10DMS8Me2.

We report the preparation and structural characterization of the first persilylated metallocene via metalation of decabromoferrocene. Whereas Grignard conditions turned to be insufficient due to steric and electronic effects of...