Improved synthesis and X-ray crystal structure of pentafluorophenylcobalt tricarbonyl triphenylphosphine

An improved synthesis of the cobalt(I) aryl complex C6F5Co(CO)3PPh3 has been developed. Reaction of [Co(CO)4]− anion with pentafluorobenzoyl chloride yields C6F5Co(CO)4, which reacts with PPh3 at 0 °C to give the title compound. This compound has been characterized by IR, NMR (1H, 19F, and 31P), elemental analysis, and X-ray crystallography. The structure shows the expected trigonal bipyramidal geometry about the cobalt atom, with the three coordinated carbonyls lying in the trigonal plane and the PPh3 and C6F5 ligands occupying the axial positions.