SYNTHESIS, CHARACTERIZATION, ANTIOXIDANT ACTIVITY EVALUATION OF 3d METALS COMPLEXES WITH N(4)-((3)-ETHYL BENZOATE) THIOSEMICARBAZONES OF 2-FORMYL(2-ACETYL, 2-BENZOIL)PYRIDINE

The paper presents the synthesis of new coordination compounds of Cu(II), Mn(II), Fe(III) Co(III), Ni(II) and Zn(II) with N(4)-((3)-ethyl benzoate)thiosemicarbazones of 2-formyl pyridine derivatives obtained through the condensation of N(4)-((m)-ethyl benzoate) thiosemicarbazide with 2-pyridinecarboxaldehyde, 2-acetylpyridine and 2-benzoylpyridine. The characterization of new compounds was done by 1H NMR, 13C NMR, IR spectroscopy, conductivity and elemental analysis. In addition, the structures of the ligands (HL1,3) were determined by single-crystal X-ray diffraction. The effect of these complexes on antioxidant activity were studied and compared with those of free ligands. The best result was found to be on coordination compound [Zn(L1)Cl], with IC50 = 11.45 µM, it is better than the free ligand HL1, IC50 = 13.15 µM and is better than the substance Trolox, IC50 = 15.86 µM (it is a pronounced antioxidant taken as a control substance)