COII, NIII AND CDII COMPLEXES DERIVED FROM MIXED AZO-LINKED SCHIFF-BASE LIGANDS: FORMATION, CHARACTERISATION, THERMAL ANALYSIS AND BIOLOGICAL STUDY.

The study includes preparation and characterisation of mixed azo-linked Schiff-base ligands and their complexes. The starting material was isolated from the mixing of 2-amino pyridine diazonium salt with 2-amino-phenole and 4-amino-3-hydroxy-1-naphthalene sulfonic acid respectively in 1:1 mole ratio in water. In this work, the formation of azo-linked Schiff-base ligands are reported. Ligands of the azo-linked Schiff-base was achieved by the reaction of starting material with 4-(dimethylamino) benzaldehyde) (HL¹ and HL²). The complexes were prepared by mixing the azo-linked Schiff-base ligands with the metal salts; Co^II, Ni^II and Cd^II in a 1:1:1 mole ratio. Ligands and complexes were characterised by analytical and spectroscopic analyses including; microanalysis, chloride content, thermal analysis, magnetic susceptibility for complexes, conductance, FTIR, UV-Vis and ¹H-NMR spectroscopy. Physico-chemical techniques indicated complexes demonstrated six coordinate structures in the solid and solution sate. Biological activity of the ligands and their metal complexes were screened for their antimicrobial activity against four bacterial species (Escherichia coli and Enterobacter (G-)), (Bacillus stubtilis and Staphylococcus aureus (G+)). [ABSTRACT FROM AUTHOR]