SYNTHESIS, SPECTRAL AND THERMAL STUDIES OF CO(II), NI(II), CU(II) ANDZN(II) COMPLEXES OF SCHIFF-BASES DERIVED FROM 2-AMINO-5-ARYL-1,3,4-THIADIAZOLE

Some transition metal complexes of the type ML2. nH(2)O [where M = Co( II), Ni(II) and Cu(II); n = 2 and when M = Zn, n = 0; L = anion of the Schiff bases derived from the condensation of 2-amino-5-phenyl-1,3,4- thiadiazole with 2-hydroxy-1-naphthaldehyde (HL1) or 2-hydroxyacetophe none (HL2) and derived from 2-amino-5-(2-methoxyphenyl)-1,3,4-thiadiaz ole and 2-hydroxybenzaldehyde (HL3) or 2-hydraxyacetophenone (HL4)] ha ve been synthesized and characterized by elemental analyses, molar con ductance, magnetic measurements, infrared and electronic spectral stud ies. The analytical data show 1:2 metal to ligand stoichiometry of the complexes. Magnetic moments, along with electronic spectral data, sug gest a distorted octahedral geometry for the Co, Ni and Cu complexes, whereas, a tetrahedral structure has been proposed for the Zn complexe s. The presence of water molecules in the Co(II), NI(II) and Cu(II) co mplexes is also indicated by the thermal studies.