Application of the spherical harmonic model to the nu(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 C-3v and C-4v fashion, respectively, in transition metal carbonyl cluster speci es they contain two sets of non-symmetry related carbonyl groups. In the ap plication of the spherical harmonic model (SHM) to the interpretation of th e infrared spectra of these compounds it proves necessary first to treat th ese as for a normal, isolated. M(CO)(4) or M(CO)(5) group and then apply th e SHM. This recognition gives insights into the general application of the SHM.