Synthesis and characterization of nickel(II), cobalt(III) and iron(III) complexes of the Schiff base 1-(2,3-dihydroxybenzylidene)thiosemicarbazone

Ni(II), Co(III) and Fe(III) complexes of the Schiff base 1-(2,3-dihydroxybenzylidene)thiosemicarbazone (Hdhbtsc) have been prepared and characterized by elemental analysis, infrared spectra, thermal analysis, molar conductivity and magnetic measurements. The results indicate the formation of 1:2 metal to ligand complexes with empirical formulae [Ni(Hdhbtsc)(2)(Cl)(2)] and [M(dhbtsc)(2)(Cl)(H2O)], (Hdhbtsc = the Schiff base; dhbtsc = anionic form of the Schiff base; M = Fe3+ or Co3+). The three new complexes are six coordinate and octahedral, where the ligands behave as bidentate chelating agents in the neutral form with Ni2+ and in the uninegatively charged form with Fe3+ or Co