Abstract
Preparation and characterization of new selenium(IV) folic acid (H2FO) complex is discussed. The coordinated behavior of the H2FO chelate and its Se(IV) complex structures have been described based on spectroscopic (infrared, Raman, electronic, H-1-NMR, and mass) analytical techniques. The H2FO acts as a chelate bi-dentate ligand with coordination involving the O atom of the two carboxylate groups. The H2FO ligand forms bi-ligand complex with general formula [Se(FO)(2)(H2O)(2)] where FO is bidentate ligand with bi-negatively charge. The infrared, Raman, electronic, H-1-NMR, and mass spectra measurement are used to identify the structure and to refer to the coordination place. Thermal analyses is used to detect the crystallization and coordinated water molecules while the decomposition of the FO ligand occur in the second sequent stage. Thermodynamic kinetic parameters as activation energy (E*), enthalpy of activation (Delta H*), entropy of activation (Delta S*) and free energy change of activation (Delta G*) are estimated using Coats and Redfern equation. The surface morphology and particle size of Se(IV) folate complex is examined using X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analyzer. Screening of antioxidant activities of selenium(IV) folate complex in-vitro is investigated. The antioxidant activity is studied by three methods (DPPH assay; beta-Carotene/linoleic acid a bleaching assay and ferric reducing power assay; the studied folate complex has a significant antioxidant activity compared to synthetic antioxidants like trolox and BHT.