A neutron diffraction study of the crystal structure of ferrocene

The structure of ferrocene has been refined with singlecrystal neutron diffraction data measured at temperatures of 173 and 298 K [Fe(^5-C5H5)2, C10H10Fe, space group PI J a, Z = 2]. The positions of all H atoms have been varied in the refinements. The cyclopentadienyl ligands are found to be significantly non-planar, with the H atoms displaced toward the Fe atom, in agreement with the results of earlier electron diffraction studies [