Bioactive N and O donor atom of bidentate Schiff base ligands from Chitosan biopolymer and its Ruthenium(III) complexes: An enhanced Antioxidant activities
The Chemical modification of chitosan was performed by the addition of cross linking agents like aromatic aldehydes which have been resulted the formation of stable bidentate Schiff base ligands. The nitrogen atom of azomethine and oxygen atom of deprotonated hydroxy/methoxy group (N and O donor atoms) in bidentate ligands are the reactive sites for the complexation with transition metal ion. The ruthenium(III) complexes, namely [Ru(CS-4Hdmb)], [Ru(CS-Hdb)], and [Ru(CS-2Hdmb)] have been derived by complexation reaction of ruthenium ion with bidentate ligands. The ruthenium(III) complexes were characterized by ESR spectroscopy and powder-XRD, SEM-EDX. The sequential morphological changes were observed in SEM images of chitosan, Schiff base and metal complexes respectively. The antioxidant property of ruthenium (III) complexes has been discussed elaborately. An excellent free radical scavenging activities of synthesized metal complexes were shown on DPPH, and LPO radicals.