Synthesis and structural characterization of a sterically encumbered ferrocenecarboxamido diphosphine and its platinum(II) complex

{[Bis(2-(diphenylphosphino)ethyl)amino]carbonyl}ferrocene (3), a bulky ferrocenecarboxamido-diphosphine, was prepared in a good yield by the reaction of pentafluorophenyl ferrocenecarboxylate (2) with bis[2-(diphenylphosphino)ethyl]amine. The NMR data (1H VT NMR study in particular) indicated a limited molecular mobility of amide 3 that presumably results from a hindered rotation around the amide C–N bond leading to a non-equivalency of the substituents attached to the amide nitrogen. Compound 3 was further converted to the corresponding diphosphine disulfide 4 and reacted with [PtCl2(cod)] (cod = η2:η2-cycloocta-1,5-diene) to give the symmetric, ligand-bridged diplatinum complex [(μ-3)PtCl2]2 (5) having cis square-planar geometry around the Pt(II) centers. The molecular structures of 4 and 5 were determined by single-crystal X-ray diffraction analysis.