Synthesis, characterization of thiosemicarabzone metal complexes and antioxidant activity in different in vitro model systems

The synthesis of bimetallic Cu(II), Co(II), Ni(II), Zn(II) and U(VI) complexes with general stoichiometry [H2L M(X2)(H2O)2] (where H2L=dideprotanated ligand and X=chloride/sulphate) were obtained by the ligand terepthaladehyde Bis(thiosemicarbazione) (H2L) has been discussed. The ligand and its binuclear complexes have been characterized by micro analysis (CHNS), 1H NMR, FT-IR, UV-vis, TG-DTA and conductance measurements. The thermal behavior of these complexes showed that the hydrated complexes loss water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The molar conductance measurements of the complexes in DMF correspond to the non-electrolytic nature of the complexes. Furthermore, the antioxidant activity of the ligand and its complexes were determined by hydroxyl radical scavenging, DPPH, NO, reducing power methods in vitro. The obtained IC50 value of the DPPH activity for the complex 2 (IC50 = 0.254 m) was shown to be better.