Efficient nuclease activity of dinuclear iron(III) complex with ligand having carboxamido nitrogen donors

A new dinucleating ligand N,N′-diphenyl-N,N′-di(pyridin-2-yl)oxalohydrazide (GampH2) has been synthesized and GampH2 gave rise to complex [Fe2(Gamp)(DMF)2Cl4], 1 with FeCl3 salt and 1 was isolated as shiny blue crystalline solid. The molecular structure of complex 1 was characterized by X-ray crystallography. In this dinuclear complex, Fe–Fe separation was found to be 5.49 Å and variable temperature magnetic moment was examined. Electrochemical investigation afforded a quasireversible redox couple with E1/2 value of 0.144 V vs Ag/AgCl. Complex 1 was efficient in DNA cleavage activity and enhancement of DNA cleavage was observed in the presence of 2-mercaptoethanol and hydrogen peroxide. Investigation of mechanism indicated possible involvement of hydroxyl radical in nuclease activity.