Browsing by Author "Tella, Adedibu C."
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Item Facile synthesis and vapochromic studies of Co(II) complexes bearing NO and OO donor ligands(Elsevier B.V., 2016-01-25) Tella, Adedibu C.; Owalude, Samson O.; Alimi, Lukman O.; Oladipo, Adetola C.; Olatunji, Sunday J.; Adeyemi, Olalere G.Two Co(II) complexes containing malonic and isonicotinic acids have been prepared by manual grinding of stoichiometric amounts of the starting materials. Elemental analysis (CHN), IR, UV-vis spectroscopic techniques,TGA-DTG investigation and X-ray powder diffraction analysis were used to characterize the two compounds. Isonicotinic acid coordinated to the metal via the pyridine ring nitrogen and one oxygen atom of the carboxylic group while malonic acid coordinated via both oxygen atoms of the carboxylate groups indicating bidentate coordination mode in the two compounds. The compounds were exposed to some volatile organic compounds (VOCs) containing nitrogen or oxygen donor atoms in the solid state and their vapochromic behaviours studied using colour changes, FT-IR and solid state UVvis spectroscopies. Heating the samples exposed to the VOCs for a few minutes at 100 °C regenerates the original material without degradation, even after several heating cycles.Item A green route approach to the synthesis of Ni(II) and Zn(II) templated metal–organic frameworks(Springer Science+Business Media New York, 2014-02-08) Tella, Adedibu C.; Owalude, Samson O.A new synthetic route involving mixing of solid reactants followed by heating has been developed for the preparation of two templated metal–organic frameworks (MOFs). [Ni(NO3)2(bipy)2](pyrene)2 (1) was obtained by mixing together Ni(NO3)2_6H2O, 4,4-bipyridine and pyrene followed by heating at 85 _C for 4 h, while [Zn2(fumarate)2(bipy)] (2) was synthesized by mixing together Zn(O2CCH3)2_2H2O, fumaric acid and 4,4-bipyridine followed by heating at 160 _C for 16 h. The materials were characterized by elemental analysis, FT-IR spectroscopy and X-ray powder diffraction analysis (XRPD). Comparison of XRPD patterns of the materials with patterns simulated from the single crystal X-ray diffraction data, obtained from Cambridge Structural database, allowed identification of the products. Conversion of solid reactants to MOFs occurs spontaneously even when reactants are not mechanically stressed. Overall, the study suggests that MOFs can be synthesized in solid state simply by mixing together appropriate reactants without co-mill (ball-mill). Compared with traditional synthetic techniques such as solvothermal, ball-milling and solution based, this method is environmentally friendly and highly efficient in the manufacture of these MOFs on a large scale.Item Hexakis(benzonitrile)ruthenium(II) bis[tetrafluoroborate(1-)]: a precursor to ruthenium organometallic compounds(Springer, 2015-11-14) Owalude, Samson O.; Odebunmi, Ezekiel O.; Eke, Uche B.; Tella, Adedibu C.; Rheingold, Arnold L.; Jackson, Randy; Suib, Steven L.The new compound, [Ru(NCC6H5)6][BF4]2, has been synthesized by reaction of the polymeric species [{RuCl2(COD)}x] (COD = 1,5-cyclooctadiene) with benzonitrile under reflux and characterized by elemental analysis, IR, NMR spectroscopic analyses, and single crystal X-ray diffraction. The Ru(II) atom is coordinated by six N atoms from six benzonitrile ligands in distorted octahedralc oordination geometry. The compound was crystallized in the monoclinic space group P21/c with unit-cell dimensions a = 10.7536(11) A ° , b = 18.6582(18) A °, c = 20.311(2) A ° , b = 91.864(2) , V = 4073.2(7) A ° 3 and final R of 0.0429.Item 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.Item Removal of hexavalent chromium from aqueous solutions by adsorption on modified groundnut hull(Elsevier B.V., 2016-11-10) Owalude, Samson O.; Tella, Adedibu C.There is an emerging serious threat to the environment from indiscriminate release of heavy metals into the wastewaters and soil from human industrial practices. In this study therefore, the uptake of hexavalent chromium, being among the major pollutants from our industries, by modified and unmodified groundnut hull was investigated. The effects of different conditions of contact time, adsorbate concentration, solution pH, and temperature on sorption process were studied. The adsorbent materials were characterized by Fourier Transform Infrared Spectroscopy (FT-IR). Analysis of the surface morphology by Scanning Electron Microscopy (SEM) revealed a change in morphology upon chromium adsorption. The adsorption process of Cr(VI) ions onto both the unmodified groundnut hull (UGS) and the modified groundnut hull (MGS) is in good agreement with the Langmuir adsorption isotherm and follows the pseudo-second-order kinetic model. According to the equilibrium studies, chromium(VI) ions are better adsorbed by modified groundnut hull.Item Solid-state synthesis of isostructural tetrachlorometallate salts of amodiaquine: crystal structure of [CdCl4][C20H24ClN3O](Springer, 2015-11-18) Tella, Adedibu C.; Owalude, Samson O.; Simon, Nzikahyel; Arise, Rotimi O.Tetrachlorometallate salts [AMDH2+][CoCl4]2- 1a and [AMDH2+][CdCl4]2- 2a (AMDH2+ = amodiaquine dication) were obtained by ball milling of amodiaquine with inorganic salts CoCl2.6H2O and CdCl2.6H2O, respectively, in the absence of solvent. Solution-based synthesis of [AMDH2+][CoCl4]2- 1b and [AMDH2+][CdCl4]2- 2b were also carried out by reaction of amodiaquine with the corresponding metal salts under reflux in methanol for 1 h. The analytical and spectroscopic data (IR, UV–Vis and NMR spectra) obtained for the compounds prepared via the two different routes are identical. The XPRD pattern of 1a closely matched the simulated pattern obtained from its reported single-crystal data. Single crystals of 2b suitable for X-ray structural analysis were obtained. The X-ray structure of 2b revealed an ionic compound with formula unit comprising of one protonated dicationic amodiaquine molecule and at etrachlorocadmate(II) anion. The crystals are triclinic with space group P-1 and unit dimensions a = 9.3272(8) A °, b = 11.1418(9) A ° , c = 12.482(10) A ° , V = 1191.89 A ° 3, and Z = 2. The amodiaquine molecule is protonated both at the quinoline and quinuclidine nitrogen atom. Antimalarial efficacy of 1a on Plasmodium berghei-infected mice were investigated, and the results revealed an enhanced activity of the compound by significantly (p\0.05) improving the suppression of parasitemia in established infection when compared with the controls.Item Solvent-free mechanochemical synthesis and X-ray studies of Cu(II) and Ni(II) complexes of 5-(3,4,5-Trimethoxybenzyl)pyrimidine-2,4-diamine (Trimethoprim) in a ball-mill(Elsevier B.V., 2016-02-10) Tella, Adedibu C.; Eke, Uche B.; Owalude, Samson O.Solvent-free synthesis of [Cu(CH3COO)2(TMP)2](1) and [Ni(CH3COO)2(TMP)2](2) by ball milling of Cu(CH3COO)2.H2O and Ni(CH3COO)2.4H2O with Trimethoprim in the absence of solvent is described. Conventional synthesis of 1. CH3OH and 2.CH3OH was carried out by the reaction of metal acetate salt and Trimethoprim using the solution-based method (reflux in CH3OH for 2 h) for comparison purposes. The mechanochemical products were characterized by comparison of melting points, conductivity values, spectral data, XRPD patterns with those of free ligand and solution based conventional synthesis products. X-ray diffraction patterns of the complex were similar to the simulated pattern of the complex obtained from single crystal structure suggesting the formation of identical compounds as obtained in solvent medium. The process presented here is operationally simple, environmentally benign and affords excellent yields without the need for solvents or external heating. Clearly, it can present a higher efficiency in terms of materials, energy and time compared to classical solution phase synthesis.Item The Synthesis and Structure of Hexakis(dimethylphenylphosphonite)ruthenium(II) bis[tetraphenylborate(–1)](WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2014-02-12) Owalude, Samson O.; Odebunmi, Ezekiel O.; Eke, Uche B.; Tella, Adedibu C.; Rheingold, Arnold L.; Suib, Steven L.Treatment of the hydrazine salt [Ru(COD)(H2NNH2)4][BPh4]2 with excess of P(OMe)2Ph in acetone gave a homoleptic complex trans-[Ru{P(OMe)2Ph}6][BPh4]2, which was characterized by IR, 31P{1H}, 13C{1H}, and 1H NMR spectroscopy, elemental analysis, and X-ray crystallography. The ruthenium in the complex has distorted octahedral coordination arrangement and bonded to all the six P(OMe)2Ph molecules through the phosphorus atoms.Item Synthesis of copper–isonicotinate metal–organic frameworks simply by mixing solid reactants and investigation of their adsorptive properties for the removal of the fluorescein dye(Royal Society of Chemistry, UK, 2014-06-23) Tella, Adedibu C.; Owalude, Samson O.; Ojekanmi, Christianah A.; Oluwafemi, Oluwatobi S.The formation of [Cu(INA)2] (INA = isonicotinate) metal–organic frameworks (MOFs) by a highly efficient and environmentally benign method simply by mixing and heating solid reactants without milling has been investigated. The materials were characterized using elemental analysis, FT-IR spectroscopy and powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Comparison of PXRD patterns of the materials with patterns simulated from single crystal X-ray diffraction data allowed identification of the products. The adsorption properties of [Cu(INA)2] were studied using the fluorescein dye (FS). The adsorption data followed both Langmuir and Freundlich equations but was best suited to the Langmuir model. The adsorption data were also correlated with the Temkin and Dubinin–Radushkevich adsorption model and the results showed that the adsorption process is physical. These results indicate that the adsorption of FS on [Cu(INA)2] is partly due to electrostatic interaction between fluorescein and the adsorbent. Compared with the traditional synthetic techniques, this method for the synthesis of MOFs was found to be highly efficient, environmentally benign and useful for the large-scale production.Item Synthesis of new ruthenium(II) complexes derived from labile nitrile ligands: an alternative route to the preparation of transdichlorotetrakis(diphenylphosphine)ruthenium(II)(Taylor and Francis, UK., 2017-03-19) Owalude, Samson O.; Tella, Adedibu C.; Odebunmi, Ezekiel O.; Eke, Uche B.; Golen, James E.; Rheingold, Arnold L.; Mahlaka, Thabo Joel; Meijboom, ReinoutNew ruthenium(II) complexes containing labile nitrile ligands have been prepared by treatment of either the polymer [{RuCl2(COD)}x] (COD = cycloocta-1,5-diene) (1) or its derivative [RuCl2(COD)(NCCH3)2]·NCCH3 (2) with the appropriate nitrile ligands in refluxing acetonitrile under argon. A new route to synthesis of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II) (7) was also reported. A redetermination of the structure of 7 was undertaken and X-ray crystallographic data revealed that the complex crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.7016(9) Å, b = 13.0847(10) Å, c = 14.1498(10) Å, α = 101.46(3)°, V = 2080.6(3) Å3, Z = 2 and R = 0.0309. Its polymorph 7′ was also obtained. The crystal structure of 4 was also determined. This complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.0510(3) Å, b = 11.0984(13) Å, c = 13.0450(16) Å, α = 90°, V = 3886.5(8) Å3, Z = 8 and R = 0.0282.Item Synthesis of zinc-carboxylate metal-organic frameworks for the removal of emerging drug contaminant (amodiaquine) from aqueous solution(Elsevier B.V., 2018-06-27) Tella, Adedibu C.; Owalude, Samson O.; Olatunji, Sunday J.; Adimula, Vincent O.; Elaigwu, Sunday E.; Alimi, Lukman O.; Ajibade, Peter A.; Oluwafemi, Oluwatobi S.We herein report the removal of amodiaquine, an emerging drug contaminant from aqueous solution using [Zn2(fum)2(bpy)] and [Zn4O(bdc)3] (fum = fumaric acid; bpy = 4,4-bipyridine; bdc = benzene-1,4-dicarboxylate) metal–organic frameworks (MOFs) as adsorbents. The adsorbents were characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, and powder X-ray diffraction (PXRD). Adsorption process for both adsorbents were found to follow the pseudo-first-order kinetics, and the adsorption equilibrium data fitted best into the Freundlich isotherm with the R2 values of 0.973 and 0.993 obtained for [Zn2(fum)2(bpy)] and [Zn4O(bdc)3] respectively. The maximum adsorption capacities foramodiaquine in this study were found to be 0.478 and 47.62 mg/g on the [Zn2(fum)2(bpy)] and [Zn4O(bdc)3] MOFs respectively, and were obtained at pH of 4.3 for both adsorbents. FT-IR spectroscopy analysis of the MOFs after the adsorption process showed the presence of the drug. The results of the study showed that the prepared MOFs could be used for the removal of amodiaquine from wastewater.Item Synthesis, characterization, crystal structure and antimicrobial studies of a novel Cu(II) complex based on itaconic acid and nicotinamide(Elsevier B.V., 2016-07-12) Tella, Adedibu C.; Owalude, Samson O.; Ajibade, Peter A.; Simon, Nzikahyel; Olatunji, Sunday J.; Abdelbaky, Mohammed S.M.; Garcia-Granda, SantiagoA novel complex was synthesized from Cu(II), nicotinamide and itaconic acid and is formulated as [Cu(C5H4O4)2(C6H6N2O)2(H2O)2$2(H2O)] (1). The compound was characterized by elemental analysis, FTIR spectroscopy, UV-Vis and single crystal X-ray diffraction. The complex crystallizes in the triclinic P-1 space group, with a = 7.5111(2) Å, b = 9.8529(3) Å, c = 10.5118(4) Å, a = 116.244(3), b = 90.291(3)o, g = 103.335(3)o, V = 673.81(4) Å3, Z = 1.The octahedral geometry around the copper(II) ion is of the form CuN2O4 consisting of two molecules of nicotinamide acting as monodentate ligand through the nitrogen atoms, two molecules itaconate ligand and two coordinated water molecules each coordinating through the oxygen atoms. The structure of 1 showed infinite chains build up linking the molecules together via strong O-H....O and N - H....O intermolecular hydrogen bonds generating a two dimensional network sheet along c axis. The antimicrobial study of the synthesized complex 1 was investigated and showed higher antibacterial activity against all the organisms comparing with Copper(II) nicotinamide 2 and Copper(II) itaconate 3.Item 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.Item 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.Item Synthesis, thermal properties, and biological study of metal(II) nicotinamide complexes containing fumarate dianion and fumaric acid: Crystal structure of [Ni(H2O)4(nia)2](fum)·(H2fum)(Taylor and Francis, UK., 2017-02-28) Tella, Adedibu C.; Owalude, Samson O.; Mehlana, Gift; Olatunji, Sunday J.; Adetitun, David O.; Kolawole, Mathew O.; Simon, Nzikahyel; Alimi, Lukman O.New divalent transition metal nicotinamide (nia) complexes containing fumarate (fum) dianion and fumaric acid (H2fum), [M(H2O)4(nia)2](fum)¢(H2fum) [M = Co (1), Cu (2), and Ni (3)] have been synthesized. The compounds were characterized by elemental analyses, infrared, UV-vis, XRPD, and TGA. Structural analysis of 3 using single-crystal X-ray diffraction technique revealed that the Ni(II) ion is coordinated by four aqua and two nia ligands in an octahedral geometry. The structure of 3 is completed with fumarate (fum2¡) dianion acting as a counterion while fumaric acid (H2fum) is present as a molecule of solvation. The three complexes were investigated for biological activities.