F. A. Nour El-Dien

PREPARATION, CHEMICAL CHARACTERIZATION, AND ELECTRONIC SPECTRA OF 6-(2-PYRIDYLAZO)-3-ACETAMIDOPHENOL AND ITS METAL COMPLEXES

The stereochemistry of new iron(III), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) complexes of 6-(2-pyridylazo)-3-acetamidophenol (H2L) is studied on the basis of their analytical, spectroscopic, magnetic, thermal and conductance data. The dissociation constant of the ligand as well as the stability constants of its metal complexes have been determined spectrophotometrically. On the basis of the infrared spectra the coordination behaviour of the ligand to the metal ions is investigated. Magnetic susceptibility and solid reflectance spectral measurements are used to infer the structure. The prepared complexes are found to have the general formulae [M(HL)(H2O)x](A) · yH2O (M = Cu(II), Zn(II), Cd(II) and Fe(III); HL = 6-(2-pyridylazo)-3-acetamidophenolate; A = acetate in case of Cu(II) and Zn(II) or chloride in case of Cd(II) and Fe(III), x = 1–3 and y = 0–5) or [M(H2L)(H2O) x ]Cl2 · yH2O (M = Ni(II) and Co(II); H2L = 6-(2-pyridylazo)-3-acetamidophenol, x = 3 and y = 5–6).

Thermal Behaviour of Metal Complexes of 6-(2-Pyridylazo)-3-acetamidophenol

The present work aims chiefly to study the thermal behaviour of complex compounds with general formula: [M(HL)⋅xH2O](A)⋅yH2O (where HL=C13H11N4O2=6-(2-pyridylazo)-3-acetamidophenol (PAAP), M=Cu(II), Zn(II), Cd(II) and Fe(III) x=1, 3; y=2, 5) while A=CH3COO− (Ac), Cl2. The second formula is [M(H2L)⋅xH2O]Cl2⋅yH2O, (where H2L=C13H12N4O2 (PAAP), M=Ni(II), Co(II) x=3; y=4, 6). The compounds were identified by elemental analysis, FT-IR spectra and TG/DTG,DTA methods. It was found that during the thermal decomposition of complex compounds water molecules of crystallization are released in the first step. In the next step the pyrolysis of organic ligand takes place. Metal oxide remained as a solid product of the thermal decomposition. Mass spectroscopy has been used for the determination of the thermal decomposition on the intermediate products. It was found that the thermal stability of the studied compounds increases as the ionic radii decreases. The activation energy E, the entropy change ΔS*, the enthalpy ΔH* change and Gibbs free energy change ΔG* were calculated from TG curve.

Metal complexes of omeprazole. Preparation, spectroscopic and thermal characterization and biological activity

Metal complexes of omeprazole (OPZ) are prepared and characterized based on elemental analyses, IR, diffuse reflectance, magnetic moment, molar conductance and thermal analyses (TGA and DTA) techniques. From the elemental analyses, the complexes have the general formula [M(L)2]X n [where M = Cr(III) (X = Cl, n = 3), Ni(II) (X = ClO4, n = 2) and Zn(II) (X = Cl, n = 2)], and [M(L)2(H2O)2]X n · yH2O (where M = Fe(III) (X = Cl, n = 3, y = 0), Co(II) (X = Cl or ClO4, n = 2, y = 0–4) and Ni(II) (X = Cl, n = 2, y = 4) and [Cu(L)2]Cl2 · H2O. The molar conductance data reveal that all the metal chelates are 3 : 1 electrolytes (for Cr(III) and Fe(III) complexes) and 2 : 1 (for the remaining complexes). IR spectra show that OPZ coordinates to the metal ions as neutral bidentate with ON donor sites of the pyridine–N and sulphone-O. The magnetic and solid reflectance spectra indicate octahedral (FeCl3, CoCl2, CoClO4 and NiCl2), square planar [Cu(II)] and tetrahedral [Mn(II), Cr(III), NiClO4 and Zn(II)] structures. The thermal behavior of these chelates using thermogravimetric and differential thermal analyses (TGA and DTA) techniques indicate the hydrated complexes lose water of hydration followed immediately by decomposition of the anions and ligand molecules in the successive overlapping OPZ and its metal complexes are screened for antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus flavus and fungi (Candida albicans). The activity data show the metal complexes to be more potent/antibacterial than the parent OPZ ligand against one or more bacterial species.

Two Spectrophotometric Assays for Dopamine Derivatives in Pharmaceutical Products and in Biological Samples of Schizophrenic Patients Using Copper Tetramine Complex and Tri-iodide Reagent

Two simple, rapid, and sensitive spectrophotometric methods are proposed for the determination of levodopa (LD). The first method is based on coupling of 4-aminoantipyrine (4-AAP) with one of the dopamine derivatives (LD, CD) to give a new ligand that reacts with copper tetramine complex to give intensely colored chelates. The colored products are quantified spectrophotometrically at 525 and 520 nm for LD and CD, respectively. The optimization of the experimental conditions is described. The method has been used for the determination of

Structure-stability relationship of copper(II)-indol carboxylic acid derivative complexes from spectrophotometric, thermogravimetric and potentiometric studies

19.7

Thermal, Spectral and Antimicrobial Properties of New Zinc(II) Isobutyrate Compounds: Part I. Papaverine, Phenazone

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The study of new zinc(II) aliphatic carboxylate complex compounds by methods of thermal analysis

69.0

Structure identification of substituted phenol redox products by: thermogravimetric and differential thermal analysis

and

Spectrophotometric determination of peptic ulcer sulfur-containing drugs in bulk form and in tablets.

18.1

Synthesis and Thermal Behaviour of New Zinc Halogeno Complex Compounds with Phenazone and Nicotinamide

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