Basicity of metal carbonyl complexes

Interaction of eta-complexes of transition metals (Mn, Re, Cr, Mo, W) with mercury acetate and-trifluoroacetate (MA and MTFA) has been studied by means of IR-spectrometry. It is stated that eta5-cyclopentadienyl complexes of Mn and Re as well as eta6-benzene complexes of Cr, Mo and W react with MA and MTFA via an atom of the transition metal (centre of the highest basicity). Coordination throUgh a metal atom is followed by an increase in the frequencies and changes in the intensity of ν CO bands. It is supposed that adducts with coordination of Hg through a metal atom may appear to be intermediate compoOnds following mercurization of metal cyclopentadienyl compleXes to form a cyclic ligand