AN INFRARED SPECTROSCOPIC STUDY ON HOFMANN-TYPE COMPLEXES OF DIMETHYL-SULFOXIDE

The infrared spectra of M(DMSO)(2)NI(CN)(4) (M=Mn, Co, Fe, Cu; DMSO=di methyl sulfoxide) and M(DMSO)(py)Ni(CN)(4), (M = Mn, Ni; py pyridine) complexes are reported. In all the complexes, the S=O stretch is shift ed to a lower frequency than in the free molecule, indicating coordina tion through oxygen. Several modes of the pyridine in the M(DMSO)(py) Ni(CN)(4) complexes have upward shifts in frequency compared to those in the free molecule, indicating that the molecule does not act as a g uest molecule in the M(DMS0)(2)Ni(CN)(4) host lattice, but is bonded d irectly to the metal (M) together with dimethyl sulfoxide.