bis-Hydrazine metal and mixed metal m-nitrobenzoates: Synthesis, spectral, thermal and X-ray diffraction studies

Abstract

bis-Hydrazine metal(II) m-nitrobenzoates, [M(m-NO2C6H4COO)2(N2H4)2], where M = Co, Ni, Zn or Cd have been prepared by the stoichiometric reaction between the aqueous solution of respective metal nitrate hydrate with aqueous solution containing a mixture of m-nitrobenzoic acid and hydrazine hydrate in appropriate ratio. These complexes have been characterised by analytical, spectral, thermal and X-ray powder diffraction studies. The IR spectra indicate the bridging bidentate nature of hydrazine moieties and monodentate nature of carboxylate ions. All these complexes except zinc complex undergo one step decomposition to yield respective metal oxide as the final product. However, the zinc complex undergoes dehydrazination in the first step followed by ligand pyrolysis to give ZnO as the final residue. X-ray powder diffraction patterns indicate that the complexes are isomorphous. The mixed metal complexes, [M1/3Co2/3(m-NO2C6H4COO)2(N2H4)2] have also been prepared using aqueous solution containing a mixture of metal nitrate hydrates and cobalt nitrate hexahydrate in 1:2 ratio instead of metal nitrate hydrate. These complexes on thermal degradation yield respective metal cobaltites as the final product. The formations of these cobaltites were confirmed by chemical analysis, IR spectra and X-ray powder diffraction studies.