Preparation and structures of 1′-(diphenylphosphino)ferrocenecarboxaldehyde and {1′-(diphenylphosphino)ferrocenyl}methanol

Ferrocenophane-ring opening in (ferrocene-1,1′-diyl)phenylphosphine with phenyl lithium followed by reaction with N,N-dimethylformamide affords 1′-(diphenylphosphino)ferrocenecarboxaldehyde (1) in good yield. Aldehyde 1 and 1′-(diphenylphosphino)ferrocenecarboxylic acid are nearly quantitatively reduced to {1′-(diphenylphosphino)ferrocenyl}methanol (2). Compounds 1 and 2 have been characterized by IR, NMR and electron-impact mass spectroscopy and their structures determined by single-crystal X-ray diffraction. The molecular structures of 1 and 2 in the solid state do not differ significantly. However, whereas the packing of aldehyde 1 is essentially molecular, alcohol 2 forms supramolecular structures via extensive hydrogen O–H⋯O bonding.