الفهرس | Only 14 pages are availabe for public view |
Abstract New Co(II, III), Ni(II) and Cu(II) complexes have been synthesized with Schiff base derived from condensation of N(4)antipyrinylthiosemicarbazide with salicyladehyde (H2L1) and 2- hydroxynaphthaldehyde (H2L2). The ligands and their metal complexes are characterized by experimental elemental analyses, conductivity measurements, FT-IR, UV-Vis, magnetic susceptibility, ESR spectral analysis, thermal thermogravimetric analyses and theoretical DFT studies. The TD-DFT calculation results have been used to expect and explain the experimental results. The infrared spectra show that the salicylaldehyde N(4)- antipyrinylthiosemicarbazone ligand (H2L1) behaves as tridentate ligand (ONS), either in the thione or thiolato form. Stereochemistries are proposed for the complexes on the basis of both spectral and magnetic properties. Along with the experimental spectral data of the starting ligand, its corresponding predicted ones were obtained using the state of art density functional theory (DFT) in gas and solvent phases. The obtained results showed a relatively good correlation between the calculated and experimental spectral data. Analytical and spectral data indicate that the 2-hydroxy-1- naphthaldehyde N(4)- antipyrinylthiosemicarbazone ligand (H2L2) behaves as tridentate ligand (ONS). The Uv-Vis, magnetic moments, ESR and DFT studies show that all copper(II) complexes have square planar geometry. However, the experimental and DFT studies showed that Cobalt(II) and Nickel(II) complexes exhibit tetrahedral geometry. The investigated Schiff thiosemicarbazones ligand and its complexes were tested for biological activity against Staphylococcus aureus and Escherichia coli representing Gram-positive and Gramnegative bacteria respectively. The data proved that the investigated compounds have in vitro antibacterial activity. The antibacterial studies of the prepared compounds screened against pathogenic bacteria indicates that copper(II) complexes have higher activi. |