title: Correlation between ionic radii of metals and thermal decomposition of supramolecular structure of azodye complexes.
abstract: An interesting azodye heterocyclic ligand of copper(II), cobalt(II), nickel(II) and uranyl(II) complexes have been synthesized by the reaction of metal salts with 5-(2,3-dimethyl-1-phenylpyrazol-5-one azo)-2-thioxo-4-thiazolidinone (HL) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)H and (13)C NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structures of the ligand tautomers are optimized theoretically and the quantum chemical parameters are calculated. The IR spectra showed that the ligand (HL) act as monobasic tridentate/neutral bidentate through the (-N=N), enolic (C-O)(-) and/or oxygen keto moiety groups forming a five/six-membered structures. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The molar conductivities show that all the complexes are non-electrolytes. The ESR spectra indicate that the free electron is in dxy orbital. The calculated bonding parameter indicates that in-plane σ-bonding is more covalent than in-plane π-bonding. The coordination geometry is five/six-coordinated trigonal bipyramidal for complex (1) and octahedral for complexes (2-6). The value of covalency factor β1(2) and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. The synthesized ligand (HL) and its Cu(II) complexes (1, 2 and 4) are screened for their biological activity against bacterial and fungal species. The ligand (HL) showed antimicrobial activities against Escherichia coli. The ligand (HL) and its Cu(II) complexes (2 and 4) have very high antifungal activity against Penicillium italicum. The inhibitive action of ligand (HL), against the corrosion of C-steel in 2M HCl solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).
authors.affiliation: Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt. Electronic address: elsonbatisch@yahoo.com.
authors.forename: A Z
authors.initials: AZ
authors.lastname: El-Sonbati
authors.affiliation: Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt.
authors.forename: M A
authors.initials: MA
authors.lastname: Diab
authors.affiliation: Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt.
authors.forename: A A
authors.initials: AA
authors.lastname: El-Bindary
authors.affiliation: Engineering Chemistry Department, High Institute of Engineering & Technology, Damietta, Egypt.
authors.forename: A M
authors.initials: AM
authors.lastname: Eldesoky
authors.affiliation: Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt.
authors.forename: Sh M
authors.initials: ShM
authors.lastname: Morgan
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D004396:Coloring Agents / Q000737:chemistry* / Q000494:pharmacology; D058266:Dielectric Spectroscopy; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D005658:Fungi / Q000187:drug effects; D007477:Ions; D007700:Kinetics; D008024:Ligands; D060328:Magnetic Phenomena; D008670:Metals / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D066244:Proton Magnetic Resonance Spectroscopy; D011720:Pyrazoles / Q000737:chemistry; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013113:Spin Labels; D013237:Stereoisomerism; D013696:Temperature; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007477:Ions; D008024:Ligands; D008670:Metals; D011720:Pyrazoles; D013113:Spin Labels
keywords: Corrosion inhibition; EIS study; ESR study; Pyrazolone azodye; Supramolecular structure of complexes; Thermodynamic parameters