Synthesis, characterization, thermal behavior and antimicrobial activity of 3-methyl benzoate complexes of transition metal with hydrazine

Abstract

Reaction of the ligands, 3-methyl benzoic acid (mbH) and  hydrazine with transition metal ions form the complexes of formulae, [M(N₂H₄)₂(mb)₂].H₂O  where M = Co(II) and Zn(II) at pH = 5-6, [M(N₂H₄)_n(mb)₂].xH₂O where M = Ni(II), n = 2, x = 0 at pH = 5 and M = Cd, n = 1, x = 1  at pH = 6. The same acid also forms metal carboxylates with zinc and copper of formula, [Zn(mb)₂H₂O].H₂O at pH = 6 and [Cu(mb)₂].H₂O at  pH = 5, respectively. The IR spectra of the complexes show that hydrazine is present as bridging bidentate ligand and the carboxylic acid as monodentate bridging carboxylate anion. The electronic spectra, magnetic moments and ESR spectral data suggest the coordination number. Thermal studies show that cobalt, zinc and nickel complexes containing hydrazine, and carboxylates of copper, zinc on their thermal decomposition form the corresponding metal oxides in nano size in the temperature range 755-815 °C. The  antibacterial and antifungal activity show that both activities of the complexes are higher than that of the acid and among the complexes, cadmium compound shows more antimicrobial activity towards bacteria and fungi.

KEY WORDS: Hydrazinium complexes, 3-Methyl benzoic acid, Thermal analysis, IR, Electronic spectra, Biological activity

Bull. Chem. Soc. Ethiop. 2016, 30(2), 241-252. 

DOI: http://dx.doi.org/10.4314/bcse.v30i2.8