THE CRYSTAL AND MOLECULAR-STRUCTURE OF (MU(5)-PENTAPHENYLCYCLOPENTADIENYL) (MU(5)-CYCLOPENTADIENYL)IRON(II), 1,2,3,4,5-PENTAPHENYLFERROCENE, [FE(C5PH5)(C5H5)]

The preparation and characterization of [Fe(C5Ph5)(C5H5)] by single-cr ystal X-ray diffraction are reported. The compound crystallizes from c hlorobenzene as a chlorobenzene solvate. The (C5H5) ring is planar to within 0.002 angstrom, whilst the C5 ring of the (C5Ph5) ligand is pla nar to within 0.004 angstrom. The Fe-(ring centroid) distances are bot h 1.652 angstrom. The phenyl substituents of the (C5Ph5) ring are cant ed relative to the cyclopentadienyl frame at angles between 44.3-degre es and 61.8-degrees. The structure of [Fe(C5Ph5)(C5H5)] is compared wi th the structures of ferrocene, 1,2,3,4,5-pentamethylferrocene and 1,2 ,3,4,5-penta(p-tolyl) ferrocene. The synthesis and characterization of [Fe(C5Ph5)(CO)2]2 is also reported. [Fe (C5Ph5)(CO)2]2 is assigned a trans configuration on the basis of its IR spectrum.