Chemistry of polynuclear compounds. Part IX. Infrared spectra of some mercury–metal carbonyl complexes

Abstract

The far infrared spectra of a series of complexes containing a mercury–transition metal bond have been determined. The mercury–metal stretching frequencies have been assigned. It is apparent that, in many of the complexes, a considerable mixing of the various vibrations within the molecule occurs. For complexes containing the binuclear-mercury–metal grouping, the intensity of the metal–mercury vibrations mainly arises from coupling with the mercury–halogen vibration. The infrared spectra in the metal–carbonyl stretching region are discussed in terms of the Cotton–Kraihanzel model. The force constants indicate that π-bonding may occur between the metals in the complexes XHg–Mn(CO)₅(X = Cl, Br, or I) and R₃Sn–Mn(CO)₅(where R = Ph or Cl).