Interpretation of the ν(CO) vibrational spectra of cluster compounds: tetrahedral anions [Fe2Ir2(CO)12]2−, [HFe2Ir2(CO)12]− and [FeIr3(CO)12]−

The analysis of the ν(CO) infrared and Raman spectra of the title compounds demonstrates the feasibility of using reliable force constant data from a model species in the interpretation of the vibrational spectra of another. This parameter transferability, similar to that used in the Extended Huckel method, should lead to a progress in understanding the vibrational CO spectra of more complex, low symmetry metal carbonyl cluster compounds.