Ruthenium (III) complexes derived from complexation of metal ion with azomethine linkage of chitosan biopolymer Schiff base ligand – Spectral, crystalline characterization and anti-oxidant activity

The chelation properties of chitosan primarily from its molecular structure and it has a high density of amino (-NH₂) and hydroxyl (-OH) groups. These groups can act as binding sites, enabling chitosan molecule to chelate with various metal ions through coordination bonds. Ruthenium metal complexes Ru[Chi4Hy3mbd(H2O)2].(Cl2)2, Ru[Chi2Hybd(H2O)2].(Cl2)2 and Ru[Chi2Hy3mbd(H2O)2].(Cl2)2 were synthesized by complexation reaction of chitosan Schiff base bidentate ligands. The synthesized metal complexes were characterized by 1H-NMR, ESR spectroscopy and the crystalline, morphological changes were examined. The in-vitro antioxidant property of these ruthenium (III) complexes has been discussed extensively. From antioxidant date, good free radical scavenging activities of these metal complexes were shown on DPPH and LPO free radicals.