I have synthesized metal complexes of Schiff bases and some of the complexes experienced higher activity than its ligands but some others showed lower activity than Schiff bases. Why this sort of contradiction happened in our case?
Method is DPPH assay
Dear Anjali Krishna G many thanks for sharing this very interesting chemical question with the RG community. I assume that there is no such general trend that the antioxidant activity of metal Shiff base complexes is higher than that of the Schiff base ligands themselves. It is, however, difficult to give you a qualified answer without knowing any details about the specific ligands and metals which you used. There could be functional groups present in the ligands which have a reducing (antioxidant) effect. More likely, however, is that the observed effect depends largely on the employed metals. For example, divalent iron (Fe2+) is a reducing agent (antioxidant).
Good luck with your research and best wishes, Frank Edelmann
You can't make a general conclusion based on several experiments using a single antioxidant protocol. Commonly, transition metals are pro-oxidants.
Kawakib Abdulaziz Have you ever heard about plagiarism?
PS The post of Kawakib Abdulazia has been deleted by RG administration.
Generalized statement can not be provided in this case. It all depends on the capability of the system to scavenge the free radicals. The exact mechanism to justify why some metal complexes have better anti-oxidant behavior when compared to that of the ligands is not yet known.
