APPLICATION OF THE SPHERICAL HARMONIC MODEL TO THE (CO) VIBRATIONAL SPECTRA OF SOME FE(CO)4 AND M(CO)5 (M=CR, W) TRANSITION METAL CLUSTER CARBONYL SPECIES

When the Fe(CO)4 and M(CO)5 (M=Cr, W) groups are co-ordinated in C3v and C4v fashion, respectively, in transition metal carbonyl cluster species they contain two sets of non-symmetry related carbonyl groups. In the application of the spherical harmonic model (SHM) to the interpretation of the infrared spectra of these compounds it proves necessary first to treat these as for a normal, isolated, M(CO)4 or M(CO)5 group and then apply the SHM. This recognition gives insights into the general application of the SHM.