Protonation of Ferrocene: A Low-Temperature X-ray Diffraction Study of [Cp2FeH](PF6) Reveals an Iron-Bound Hydrido Ligand

Ferrocene, Cp2Fe, is quantitatively protonated in a mixture of liquid HF/PF5 to yield [Cp2FeH](PF6), which was characterized by H-1/(CNMR)-C-13 and Fe-57 Mossbauer spectroscopy as well as single-crystal X-ray diffraction analysis. X-ray diffraction analysis at 100K revealed a disordered, iron-coordinated hydrido ligand, which was unambiguously located by aspherical atom refinement at 100K, and by analyzing the non-disordered crystal structure at 30K, revealing a non-agostic structure.