147 research outputs found

    Infrared and Thermal Analysis of Vanadyl(II) Barbiturate Complex

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    An usual method for the preparation of vanadyl(II) barbiturate complex was performed under the chemical reaction of vanadyl(II) sulfate with barbituric acid (H2L) and formulated as: [VO(HL)2].2H2O. This new barbiturate complex was synthesis and characterized by elemental analysis, molar conductivity, magnetic measurements, infrared spectral method and simultaneous thermal analysis (TG/DTG) techniques. The molar conductance measurements proved that barbiturate vanadyl(II) complex is non-electrolytes. The infrared spectra of the barbituric and vanadyl(II) complex are used to identify the mode of coordination. Kinetic and thermodynamic parameters (E*, ΔH*, ΔS* and ΔG*) of H2L ligand and its complex are estimated according to the DTG curves.Â

    Spectroscopic, thermal analyses, XRD spectra and nematicidal activity study of some new N2O2 tetradentate Schiff base metal ions complexes

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    ABSTRACT. A series of metal complexes [Co(HL)2(H2O)2]Cl2.5H2O (A), [Cu(HL)2](CH3COO)2.2H2O (B), [Y(HL)2]Cl3.2H2O (C), [ZrO(HL)2H2O]Cl2.H2O (D), [La(HL)2(H2O)2]Cl3.5H2O (E) and [UO2(HL)2](CH3COO)2 (F) were prepared. The structures of the compounds in solid state were detected by micro analytical, Fourier transform IR, 1H NMR, UV-Vis, mass, X-ray diffraction spectra, molar conductivity, magnetic susceptibility measurements and TG/DTG analysis. The IR spectral data point out that the ligand behaves as tridentate in nature with Cu(II), Y(III), U(VI) and bidentate with Co(II), Zr(IV) and La(III) metal ions. The conductivity values showed that the complexes found as electrolytes and the XRD models of the complexes indicated crystalline nature. The thermodynamic parameters of compounds have been detected using Coats-Redfern and Horowitz-Metzeger methods at n = 1 and n ≠ 1 and values point out more ordered activated complex formation. The nematicidal efficacy of compounds was assessed.                     KEY WORDS: Schiff base, Spectroscopic analysis, Thermal analysis, XRD, Nematicidal   Bull. Chem. Soc. Ethiop. 2021, 35(2), 381-397. DOI: https://dx.doi.org/10.4314/bcse.v35i2.1

    Egypt beyond the crisis : medium-term challenges for sustained growth

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    The paper analyzes the impact of the recent global crisis in the context of the previous two decades'growth and capital flows. Growth decomposition exercises show that Egyptian growth is driven mostly by capital accumulation. To estimate the share of labor in national income, the analysis adjusts the national accounts statistics to include the compensation of self-employed and non-paid family workers. Still, the share of labor, about 30 percent, is significantly lower than previously estimated. The authors estimate the output costs of the current crisis by comparing the output trajectory that would have prevailed without the crisis with the observed and revised gross domestic product projections for the medium term. The fall in private investment was the main driver of the output cost. Even if private investment recovers its pre-crisis levels, there is a permanent loss in gross domestic product per capita of about 2 percent with respect to the scenario without the crisis. The paper shows how the shock to investment is magnified due to the capital-intensive nature of the Egyptian economy: if the economy had the traditionally-used share of labor in income (40 percent), the output loss would have been reduced by half.Economic Theory&Research,Debt Markets,Access to Finance,Emerging Markets,Banks&Banking Reform

    Synthesis and characterization of a tetranuclear Cu(II) coordination polymer containing pyridine-2,6-dicarboxylic acid and 4-amidinopyridine co-ligand

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    This research demonstrates the preparation of a new coordination polymer, {[Cu4(H2pydc)2(H1apy)(H2O)2DMF].DMF}n, (H2pydc = pyridine-2,6-dicarboxylic acid, H1apy = 4-amidinopyridine) under solvothermal condition by the self-assembly of pyridine-2,6-dicarboxylic acid, 4-midinopyridene and copper(II) acetate. The compound was characterized by elemental analysis and infrared spectroscopic technique. The analysis indicated that the 4-amidinopyridine coordinated to the copper ions through the terminal nitrogen in a monodentate fashion while the pyridine-2,6-dicarboxylic acids coordinated through the carboxylate oxygens in monodentate mode. Both the elemental analysis and the infrared spectroscopic data agreed with the proposed stoichiometry. This result represent the first report of a tetranuclear Cu(II) coordination polymer having coordinated 4-amidinopyridine as the nitrogen donor moiety in its structure

    Synthesis, structural characterization and biological activity of Cu(II), Co(II) and Ni(II) complexes derived from 2-(thiazol-2-ylimino)thiazolidin-4-one ligand

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    A novel series of metal complexes of 2-(thiazol-2-ylimino) thiazolidin-4-one ligand were prepared; the corresponding ligand was synthesized from reaction 2-Chloro-N-(thiazol-2-yl) acetamide with ammonium thiocyanate. The complexes are characterized by FTIR, UV-Vis, molar conductance and mass spectroscopy. The low molar conductance values indicate that the complexes are non-electrolytes.Spectroscopic studies confirmed that the ligand bonded to the metals through the sulphur atoms. Coordination number of copper and nickel complexes is four with square planar geometry, while the cobalt complex has octahedral geometry.In vitro antibacterial activity of ligand and its metal complexes was evaluated using well diffusion method and compared to the standard drug (tetracycline). The antibacterial activitywas examined against Escherichia coli, and pseudomonas aeruginosa, as gram negative bacteria and Staphylococcus aureus as gram positive bacteria. It was found that Nickel complex has the highest antibacterial activity among the synthesized compounds with Zone inhibition diameter in the range 25-29 mm

    A new simple route for synthesis of cadmium(II), zinc(II), cobalt(II), and manganese(II) carbonates using urea as a cheap precursor and theoretical investigation

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    ABSTRACT. The MnCO3.H2O, CoCO3.4H2O, ZnCO3, and CdCO3, respectively, were synthesized through a new precise, easy pathway for the reaction of MnI2, CoI2, ZnI2, or CdI2 aqueous solutions with a cheap precursor-urea for 10 h at ~ 70 oC. The IR spectra of reaction products designate the presence of characteristic bands of ionic carbonate, CO32– and absence of the individual bands of urea. The (CO3)2- ion is planar and therefore, it belongs to the D3h symmetry. It is expected to display four modes of vibrations. The stretching vibrations of the type; n(C-O) is observed in the range of (1376-1503) cm-1 while another stretching vibration n(C-O) is observed in the region 1060-1079 cm-1. The out of plane of vibration d(OCO) is observed in the range of (833-866) cm-1 while, the angle deformation bending vibration d(OCO) appear in the range of (708-732) cm-1. The infrared spectra of metal carbonate, show that, this product clearly has an uncoordinated water. The band related to the stretching vibration n(O-H) of uncoordinated H2O is observed as expected in the range of ~ 3000 cm-1. A general mechanism explaining the synthesis of carbonate compounds of cadmium(II), zinc(II), cobalt(II), and manganese(II), are described. Moreover, the DFT outcomes using B3LYP/LanL2DZ (basis set) agree with the experimental results.                 KEY WORDS: Carbonate, CoI2, Infrared spectra, Urea, DFT   Bull. Chem. Soc. Ethiop. 2022, 36(2), 363-372.                                                                DOI: https://dx.doi.org/10.4314/bcse.v36i2.10                                                     &nbsp

    A review of the anticancer properties of bee products and their molecular mechanisms: An overview on lung cancer

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    Lung cancer is one of the most common types of cancer in the world, and it represents a significant percentage of all diagnosed cancers. Despite better clinical outcomes associated with current drugs, lung cancer has a worse survival rate than any of the other commonly occurring malignancies. Evidence suggests that natural products offer promising potential for improving the current treatment approaches and/or developing novel treatment strategies. Bee products such as honey, propolis, and venom have been reported to exert anti-cancer effects on a variety of human cancer cell lines, thereby paving the way for a wide range of treatment possibilities. The current review focuses on the cytotoxic effects of bee bioactive compounds on all types of cancer, and the molecular pathways by which they might reduce tumor cell growth or trigger apoptosis of cancer cells, with particular reference to lung cancer. This strategy could potentially improve the efficacy of current remedies, reduce the doses of chemotherapy drugs, and decrease adverse effects of chemotherapy drugs. Furthermore, in vitro studies on anti-cancer properties of bee products are carefully reviewed. The results reveal that bee products have the potential to become effective treatment agents against many forms of cancer in the future

    Determination of Springback Values in Bending I-sections with Tresca Criteria

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    The springback ratio for bending I-section beams is introduced analytically in the present study. A complete analysis using the strength of materials approach is carried out with Tresca yielding criteria. Analytical methods are given in the form of equations for two cases according to the positions of the yield point along the height of the beam. The results represent the effect of different parameters affecting the springbackratio

    Synthesis and Characterization of Cu(I)-Folic Acid Complex A Theoretical and Experimental Study

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    Copper (I) complex containing folic acid ligand was prepared and characterized on the basis of metal analyses, UV-VIS, FTIR spectroscopies and magnetic susceptibility. The density functional theory (DFT) as molecular modeling calculations was used to determine the donor atoms of folic acid ligand which appear clearly at oxygen atoms binding to hydrogen. Detection of donation sights is supported by theoretical parameters such as geometry, mulliken population, mulliken charge and HOMO-LUMO gap obtained by DFT calculations
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