Synthesis and characterization of bis(nicotinamide) m-hydroxybenzoate complexes of Co(II), Ni(II), Cu(II), and Zn(II)

Mixed-ligand m-hydroxybenzoate complexes of Co(II), Ni(II), Cu(II), and Zn(II) with nicotinamide were synthesized and characterized by elemental analysis, FT-IR spectrometry, solid state UV-vis spectrometry, and magnetic susceptibility measurements. The thermal behavior of the complexes was studied by simultaneous TG-DTA methods in static air atmosphere. The infrared spectral characteristics of the complexes are discussed and the mass spectra data are recorded. The complexes contain two water molecules, two m-hydroxybenzoato (m-hba), and two nicotinamide (na) ligands per formula unit. In these complexes, the m-hydroxybenzoate and nicotinamide behave as a monodentate ligand through acidic oxygen and nitrogen of the pyridine ring. The decomposition pathways and the stability of the complexes are interpreted in terms of the structural data. The final decomposition products were found to be the respective metal oxides.