Browsing by Author "Ogunlaja, Adeniyi S."

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    Kinetics and mechanism of ruthenium(iii)-catalyzed oxidation of glycine by cerium(iv) ions in acidic medium
    (Bangladesh Chemical Society, 2017-06-29) Owalude, Samson O.; Odebunmi, Ezekiel O.; Tella, Adedibu C.; Bamigboye, Christiana A.; Adebayo, Ayinde; Ogunlaja, Adeniyi S.
    Kinetics of oxidation of glycine in acidic solution of cerium(IV) ions in presence of ruthenium(III) ions were studied. The reactions were found to be first-order with respect to [glycine], [Ru(III)] and [Ce(IV)]. The rate is proportional to [H+] while the rates was decreased with increasing [Ce(IV)], [HSO4-] and ionic strength of the medium. The observed kinetic data and the spectroscopic evidence lead to the conclusion that HCHO, (NH3+),-COOH, [RuCl2(H2O)4]+ and Ce(SO4)2 were the reactive species of glycine, Ru(III) chloride and cerium(IV) ions, respectively. Based on the kinetic data, the mechanism of the reaction for the catalytic path was proposed. It was found that Ru(III) chloride forms an intermediate complex, which subsequently reacts with the active form of Ce(IV) to yield the product with regeneration of Ru(III). Activation parameters were evaluated and provided further support to the proposed mechanism.
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    Synthesis, crystal structure and desulfurization properties of zig-zag 1D coordination polymer of copper(II) containing 4-methoxybenzoic acid ligand.
    (Taylor and Francis, UK., 2018-06-28) Tella, Adedibu C.; Owalude, Samson O.; Olatunji, Sunday J.; Oloyede, Solomon O.; Ogunlaja, Adeniyi S.; Bourne, Susan A.
    Combustion of fuels containing organosulfur compounds has resulted in the emission of sulfur oxides (SOx) into the atmosphere, therefore, causing serious environmental and health hazards. Herein, slightly distorted octahedral zig-zag 1D coordination polymer of copper(II) [Cu(4-mba)2(H2O)3] was synthesized by reacting copper sulfate pentahydrate with a carboxylate-containing ligand (H-4mba = 4-methoxybenzoic acid) and employed for sulfur compound uptake. The ligand coordinates to the copper(II) atom via two pairs of deprotonated ligating atoms (carboxylate oxygens) and two water molecules. Structural characterization also reveals that interplay of O–H···O, N–H···O, C-H···O and C–H···π interactions between lattice and coordinated water and ligands significantly contribute to the crystal packing leading to the formation and strengthening of three-dimensional supramolecular assembly. The complex, [Cu(4-mba)2(H2O)3], show potential for desulfurization of fuel with an observed adsorption capacity of 9.6 mg/g at 32°C for 6 h. DFT calculations further revealed a transfer of electron sulfur-containing compounds and the complex, [Cu(4-mba)2(H2O)3], thus leading to a stronger pi–pi interaction.
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    Synthesis, crystal structures and luminescence properties of new multi-component co-crystals of isostructural Co(II) and Zn(II) complexes
    (Elsevier B.V., 2017-12-27) Tella, Adedibu C.; Owalude, Samson O.; Omotoso, Mary F.; Olatunji, Sunday J.; Ogunlaja, Adeniyi S.; Alimi, Lukman O.; Popoola, Olugbenga K.; Bourne, Susan A.
    Two novel isostructural compounds containing multi-component co-crystals [M(C6H4NO2)2(-H2O)2](C9H6O6)2 (M = Co (1), Zn (2), C6H4NO2 = Picolinic acid, C9H6O6 = Trimesic acid) have been synthesized. The compounds were characterized by elemental analysis, FT-IR, UVeVisible and 1H NMR spectroscopies as well as thermal and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that 1 and 2 are isostructural. Compound 1 crystallizes in triclinic space group (P-1, with a = 5.154(10) Å, b = 11.125(2) Å, c = 14.113(3) Å, a = 91.01(3)o, b = 100.54(3)o, and g = 102.71(3)o). In a similar fashion, compound 2 crystallizes in triclinic space group (P-1, with a = 5.1735(3) Å, b = 11.0930(10) Å, c = 14.1554(8) Å, a = 91.70(3)o, b = 100.26(3)o, g = 102.90(3)o). The metal (II) cation presents distorted MN2O4 octahedral geometry with H2O molecules coordinated to the metal in equatorial position while the picolinic acid molecules are axially coordinated through the pyridine N atom. The two trimesic acid molecules are not part of the first coordination sphere. Compounds 1 and 2 constitute an example of a class of coordination compound of multicomponent crystals having trimesic acid outside the coordination sphere where it is neither protonated or deprotonated. The two compounds were investigated for luminiscence properties.