OICC Press Iranian Journal of Catalysis 2345-4865 14 3 2024 09 17 Preparation, characterization, and antioxidant activity of novel metal (Mn (II), Ni (II), Pd (II), Pt (IV)) complexes: Application of Pd complex in Suzuki-Miyaura cross-coupling reaction 1 24 10.57647/j.ijc.2024.1403.33 EN Areeg M. Fadhel Al-Rusafa, Baghdad Education Directorate, Ministry of Education, Baghdad, Iraq Abbas Ali Salih Al-Hamdani Department of Chemistry, College of Science for Women, University of Baghdad, Baghdad, Iraq https://orcid.org/0009-0001-2257-3278 Journal Article 2024 09 17 A novel azo dye was synthesized by reacting the N2 + (diazonium) salt derived from 2,4,6- trihydroxyacetophenone with 3-aminophenol. The resulting dye was thoroughly characterized using various analytical techniques including micro elemental analysis, Fourier-transform-infrared spectroscopy, electronic spectra, 1H NMR and 13C NMR spectrum, liquid chromatography-mass spectrum, Thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC) for the ligand. Subsequently, the dye was employed to prepare a series of complexes by reacting it with Ni (II), Pt (IV), Pd (II), and Mn (II) ions. These complexes were also subjected to comprehensive characterization, and their geometric shapes were determined using techniques such as micro elemental analysis, Fourier-transform-infrared spectroscopy, electronic spectra, proton NMR spectrum, liquid chromatography-mass spectrum, DSC, magnetic moment, conductivity, and chloride content. The results indicated that the complexes exhibited an octahedral shape, except for the palladium complex which displayed a square planar shape. Notably, the palladium complex was found to be conductive, while the other complexes were non-conductive. The nickel complex exhibited a tetrahedral shape. Furthermore, the synthesized compounds were evaluated for their antioxidant activity, and the IC50 value was determined using Ascorbic acid as a standard substance and DPPH as a free radical. The results revealed that the azo dye (H4L) exhibited higher antioxidant activity compared to ascorbic acid, followed by the Pt-complex, Mn-complex, and Ni-complex. Additionally, the Pd-complex was investigated in a Suzuki-cross coupling reaction. Lastly, all of the metal complexes were optimized using DFT calculation. Research Highlights: Preparation of new Azo compound Characterization prepared compounds preparation Mn (II), Ni (II), Pd (II), Pt (IV)) Complexes Study the Antioxidant Activity of Novel Metal Complexes Study Application of Pd Complex in Suzuki-Miyaura Cross-Coupling Reaction