Synthesis and characterization of divalent transition metal complexes of Schiff bases derived from benzoin and 4-amino benzoic acid

Author(s): A.H.Manikshete, S.K.Sarsamkar

The Schiff base (4-(2-hydroxy-1,2-diphenylethylideneamino) benzoic acid) was prepared frombenzoin and 4-amino benzoic acid and the complexes of divalentmetals ofCo (II).Ni (II) and Cu (II)were synthesized. The ligand and metal complexeswere characterized by elemental analysis, ultraviolet-visible spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, mass spectroscopy and magnetic susceptibility measurement. The ligand (HL) was synthesized by condensation of benzoin (H) and 4-amino benzoic acid (L).The geometrical structures of synthesized complexes were identified. Magnetic susceptibility and electronic spectral study of the complexes showed the octahedral geometry. The antimicrobial activity of Schiff base and the metal complexes were studied. The resultswere comparedwith standard antibiotic. Surprisingly, the ligand (HL), the cobalt complex (HL-Co) and the nickel complex (HL-Ni) have shown to be more active against the fungi Candida albicans and Aspergillus niger. The cobalt complex is active against the microorganism Staphylococcus aureus. The Pseudomanas aeruginosa is resistant to the ligand and all the metal complexes.

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