title: Synthesis, spectral characterization, molecular modeling and in vitro antibacterial activity of complexes designed from OO, NO and NN donor Schiff-base ligand [corrected].
abstract: A new chelating agent, N'-(4-methoxybenzylidene)-2-oxo-2-(phenylamino)acetohydrazide (H2OMPH) and its complexes with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Hg(II) and U(IV)O2(2+) ions have been prepared and characterized by conventional techniques. The spectral data indicated that the ligand coordinates as neutral bidentate with Cu(II), Mn(II), U(IV)O2(2+) and Hg(II), neutral tridentate with Ni(II), mononegative tridentate with Co(II) and binegative tetradentate with Zn(II) ions. On basis of magnetic and electronic spectral data an octahedral geometry for Mn(II), Co(II) and Ni(II) complexes and a square planar geometry for Cu(II) complex have been proposed and confirmed by applying geometry optimization and conformational analysis. The protonation constants of H2OMPH and the stepwise stability constants of its complexes are calculated at 298, 308 and 318 k as well as their thermodynamic parameters. Also, the Kinetic parameters (Ea, A, ΔH(*), ΔS(*) and ΔG(*)) were determined for each thermal degradation stage of some complexes using Coats-Redfern and Horowitz-Metzger methods. Moreover, the ligand and some complexes were screened for in vitro antibacterial activity against Staphylococcus epidermalies (St. epid); Streptococcus pyagenies (Strp. py.) as Gram +ve bacteria and Escherichia coli (E. coli); Klebsiella spp. (kleb. spp.) as Gram -ve bacteria using inhibition zone diameter.
authors: Department of Chemistry, Mansoura University, P.O. Box 70, Mansoura, Egypt. Electronic address: olaelgammal@yahoo.com.
authors: Ola A
authors: OA
authors: El-Gammal
authors: Department of Chemistry, Mansoura University, P.O. Box 70, Mansoura, Egypt.
authors: G
authors: G
authors: Abu El-Reash
authors: Department of Chemistry, Mansoura University, P.O. Box 70, Mansoura, Egypt.
authors: S F
authors: SF
authors: Ahmed
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D060328:Magnetic Phenomena; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry*; D020030:Nitric Oxide Donors / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D012545:Schiff Bases / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013818:Thermogravimetry
chemical_list: D000900:Anti-Bacterial Agents; D056831:Coordination Complexes; D008024:Ligands; D020030:Nitric Oxide Donors; D012545:Schiff Bases; D009569:Nitric Oxide; D010100:Oxygen
keywords: Antibacterial activity; Coats–Redfern; Horowitz–Metzger; Hydrazone derivatives; Molecular modeling; pH-metric titration