INFRARED-SPECTRA OF DIMETHYLSULFOXIDE COMPLEXES OF TRANSITION-METAL PERCHLORATES - BAND ASSIGNMENTS BY ISOTOPIC LABELING AND STRUCTURAL ASPECTS OF THE SPECTRA

The infrared spectra (1050-150 cm-1) of the complexes [M(dmso)6](ClO4)2 (dmso = dimethylsulphoxide; M = Mn, Co, Ni, Zn) [M(dmso)6](ClO4)3 (M = Sc, Fe, Ga) and [Cu(dmso)n](ClO4)2 (n = 4, 5, 6) are discussed. Assignments of ligand and metal-ligand vibrations are based on the band shifts induced by 18O-labelling of the oxygen donors, by deuteration of the methyl groups and by the effects of metal ion substitution. On the assumption of Oh site-symmetry for all the complexes except those of Cu(II), one ν(MO) band is expected and observed. The spectra of the 4-, 5- and 6-coordinate Cu(II) complexes are rationalized on the basis of D4h square-planar, C4v square-pyramidal and D4h tetragonal coordination, respectively. © 1979.