The infrared spectra of dimethylsulphoxide complexes of transition metal perchlorates: band assignments by isotopic labelling and structural aspects of the spectra

Abstract

The infrared spectra (1050-150 cm −1) of the complexes [M(dmso) 6](ClO 4) 2 (dmso = dimethylsulphoxide; M = Mn, Co, Ni, Zn) [M(dmso) 6](ClO 4) 3 (M = Sc, Fe, Ga) and [Cu(dmso) n ](ClO 4) 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 O h site-symmetry for all the complexes except those of Cu(II), one ν(MO) band is expected and observed. The spectra of the 4-, 5- and 6-coordinate Cu(II) complexes are rationalized on the basis of D 4 h square-planar, C 4 v square-pyramidal and D 4 h tetragonal coordination, respectively.