Co-ordination chemistry of thiomorpholin-3-one and thiazolidine-2-thione. Complexes of some bivalent transition-metal sulphates and nitrates

Abstract

Several complexes containing the ligands (L) thimorpholin-3-one or thiazolidine-2-thione of general formula ML_nX_m are reported {M = Zn, Cd, Co, or Ni; X =[SO₄]^2–(m= 1) and [NO₃]^–(m= 2); n= 2, 4, or 6} The complexes have been characterized by chemical analyses, ligand-field spectra, magnetic-susceptibility measurements, molecular conductance, and vibrational spectra (conventional and far infrared). Assignments for the metal–ligand modes have also been made. By use or i.r. spectroscopy it is possible to distinguish whether the anions present are co-ordinated to the transition metal ion or are present as free ions. Spectroscopic parameters for the cobalt and nickel complexes are compared with similar chromophores containing sulphur, oxygen, and nitrogen donor atoms. The evidence suggests that the zinc and cadmium complexes are tetrahedral, whereas the cobalt(II) and nickel(II) complexes are tetrahedral or octahedral.