Synthesis, spectroscopy and biological investigations of manganese(III) Schiff base complexes derived from heterocyclic β-diketone with various primary amine and 2,2′-bipyridyl

Article abstract of DOI:10.1016/j.saa.2011.03.008

The mixed ligand mononuclear complex [Mn(bipy)(HPMFP)(OAc)]ClO₄ was synthesized by reaction of Mn(OAc)₃·2H₂O with HPMFP and 2,2′-bipyridyl. The corresponding Schiff base complexes were prepared by condensation of [Mn(bipy)(HPMFP)(OAc)]ClO₄ with ethylenediamine, ethanolamine and glycine (where HPMFP = 1-phenyl-3methyl-4- formyl-2-pyrazolin-5one, bipy = 2,2′-bipyridyl). All the compounds have been characterized by elemental analysis, magnetic susceptibility, conductometry measurements and ¹H and ¹³C NMR, FT-IR, mass spectrometry. Electronic spectral and magnetic susceptibility measurements indicate square pyramidal geometry around manganese(III) ion. The thermal stabilities, activation energy E^*, entropy change ΔS ^*, enthalpy change ΔH^* and heat capacity of thermal degradation for these complexes were determined by TGA and DSC. The in vitro antibacterial and antifungal activity of four coordination compounds and ligand HPMFP were investigated. In vitro activates of Bacillus subtillis (MTCC-619), Staphylococcus aureus (MTCC-96), Escherichia coli (MTCC-722) and Klebsiella pneumonia (MTCC-109) bacteria and the fungus Candida albicans (ATCC-90028) were determined. All the compounds showed good antimicrobial activity. The antimicrobial activities increased as formation of Schiff base.