Synthesis, Characterization and Antioxidant Studies of Chalcone Derived Schiff Bases and Its Copper (II) Metal Complexes

Chew, Angel Li Jia (2022) Synthesis, Characterization and Antioxidant Studies of Chalcone Derived Schiff Bases and Its Copper (II) Metal Complexes. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

In this project, two chalcone derived Schiff bases (which were abbreviated as MTTC and MT4Cl) were synthesized by reacting4-methyl-3-thiosemicarbazide with carbonyl compounds, that are, trans-chalcone and 4-chlorochalcone, respectively, via conventional condensation and molar ratio of 1 : 1. Besides that, the copper(II) metal complexes, which are abbreviated as [Cu(MTTC)2 and Cu(MT4Cl)2] were synthesized by using the synthesized Schiff bases with Cu(II) metal salt in a molar ratio of 2 : 1. The synthesized Schiff bases and its metal complexes were characterized with various methods, including, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectrophotometer (FT-IR), Conductivity Meter, Magnetic Sus-ceptibility Balance, Ultraviolet-Visible (UV-Vis) Spectrophotometer, 1H and 13C Nuclear Magnetic Resonance Spectrophotometer (NMR), Flame Atomic Absorption Spectroscopy (F-AAS), Mass Spectrometer (MS) and Single Crystal X-ray Diffraction (SXRD). From the re-sults, it was found that the Schiff bases exist in the thione tautomer in the solid and liquid states. The antioxidant study of the Ferric Reducing Ability of Plasma (FRAP) assay was conducted to compare the antioxidant activities of the synthesized Schiff bases and its Cu(II) complexes. The results had shown that bis(((Z,Z)-N’-((E)-3-(4-chlorophenyl)-1-phenylallylidene)-N-methylcarbamohydrazonoyl)thio)copper, Cu(MT4Cl)2 exhibits better antioxidant activity as compared to its parent Schiff bases and the rest of the compounds. The better antioxidant ac-tivity of Cu(MT4Cl)2 might be contributed by its substituent chlorine atom. However, it was still not a promising antioxidant as compared to ascorbic acid because ascorbic acid showed higher antioxidant activity.