New mixed ligand saccharin complexes with o-phenylenediamine Schiff base and antioxidant investigations

Abstract

In this study, four new mixed-ligand saccharin complexes with 2-[[(2-Aminophenyl)imino]methyl]-6-methoxy phenol Schiff base and metal saccharinates (nickel, copper, zinc and cadmium) have been prepared and characterized with various methods including elemental analysis, FT-IR spectroscopy, UV-visible absorption spectroscopy, NMR spectroscopy, QTOF-LC/MS spectroscopy. All methods have confirmed the inclusion of the Schiff base obtained by condensation of o-phenylendiamine and o-vanillin into the metal saccharinates. Besides, DPPH scavenging activities and metal chelating abilities of all complexes have been determined and compared to well-known antioxidant standards (Butylated hydroxyanisole, Butylated hydroxytoluene and α-Tocopherol) along with starting metal saccharinates. According to the results, nickel complex has exhibited the best DPPH scavenging activity, while copper complex has the highest ferrous ion chelating ability.