Complexing Ability of Some 2-Spirothiazolid-4-one Derivatives

The complexes of some 2-spirothiazolid-4-one derivatives have been prepared with Cu(II), N i(II), Co(II) and Cd(II) salts. The complexes all have a metal to ligand ratios of 1:1 or 1:2 and are all believed to have tetrahedral structures with chelating ligands. Their structures are suggested on the basis of analysis, X-ray diffraction techniques, spectral (UV-VIS, IR, XH NM R), and thermal decomposition as well as conductivity measurements. The ligands are co­ ordinated to the metal ions as monovalent bidentate ligands through the OCO groups. Elec­ trical conductivity studies indicated that these complexes have activation energies in the range of semi-conducting materials. It is observed that some of the complexes are more potent as bacteriostatic agents than the free ligands.