Browsing by Author "Adedibu Clement Tella"

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    Calcium coordination compounds of dipicolinic and quinolinic acids: synthesis, characterization, crystal structures and DFT studies
    (2022) Adedibu Clement Tella; Adetola Christianah Oladipo; Victoria Tosin Olayemi; Allen Gordon; Adeniyi Sunday Ogunlaja; Lukman Olawale Alimi; Stephen Argent; Robert Mokaya; Guy Clarkson; Richard Walton
    Abstract In the past two decades various N-heterocyclic carboxylate coordination compounds have been synthesized with intriguing architectures and potential applications as functional materials. In this regard, two novel calcium coordination compounds [Ca(2,6-Hpdc)2(H2O)2] 1 and [Ca2(2,3-pdc)2(H2O)6]n 2 (where 2,6-H2pdc = 2,6-pyridinedicarboxylic acid and 2,3-H2pdc = 2,3-pyridinedicarboxylic acid) were grown at room temperature. The compounds were characterized using elemental analysis, Fourier Transform infrared (FT-IR) spectroscopy, thermogravimetric analysis, powder X-ray diffraction and single crystal X-ray crystallographic analysis. Compounds 1 and 2 crystallize in orthorhombic space group Pccn and monoclinic space group Pc, respectively. The structures of both compounds are stabilized by a network of hydrogen bonds arising from coordinated water molecules and carboxylate groups. Computational analysis revealed that compound 1 has a large energy gap (9.221 eV) suggesting high excitation energies and chemical hardness making it a better electron acceptor while compound 2 displayed a smaller energy gap (5.156 eV) which is indicative of a softer molecule with better polarizability and reactivity.
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    Synthesis, Structure, and Properties of a Dinuclear Cu(II) Coordination Polymer Based on Quinoxaline and 3,3-Thiodipropionic Acid Ligands
    (2021) Adedibu Clement Tella; Samson Owalude; Vincent Adimula; Adetola Oladipo; Victoria Olayemi; Bushra Ismail; Amara Mumtaz; Attiq Rehman; Asad Khan; Hadley Clayton; Nawaz Tahir
    Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.