Synthesis, spectroscopic characterization and antioxidant activity of Cu2+ and Co2+ dipicolinic acid complexes

The present work analyses two coordination compounds with the ligand dipicolinic acid (DPA) and the metallic phases of Cu 2+ and Co 2+ . The methodology employed was direct synthesis, using the transition metal in its elemental state and dimethyl sulfoxide (DMSO) as the oxidizing agent, with reaction times of 0.5 and 2 hours at room temperature and at 330 K, respectively, yielding ∼80 %. The formation of the coordination compounds was confirmed using a range of analytical techniques, including X-ray diffraction, UV-Vis, IR, 1 H NMR, and ESR spectroscopy. Additionally, the free electron-scavenging assay with DPPH indicates that the compounds could compete with artificial antioxidant agents, as evidenced by their IC 50 of 3 and 6 mM.