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183W NMR Spectroscopy

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Kenji Nomiya – 1st expert on this subject based on the ideXlab platform

  • Synthesis and pH-variable ultracentrifugation molecular weight measurements of the dimeric, Ti–O–Ti bridged anhydride form of a novel di-TiIV-1,2-substituted α-Keggin polyoxotungstate. Molecular structure of the [(α-1,2-PW10Ti2O39)2]10− polyoxoanion
    Journal of The Chemical Society-dalton Transactions, 2020
    Co-Authors: Kenji Nomiya, Yoshitaka Sakai, Mizuto Takahashi, Jason A. Widegren, Takao Aizawa, Noriko Chikaraishi Kasuga

    Abstract:

    The preparation and characterization of a Keggin-type, novel di-TiIV-1,2-substituted polyoxotungstate are described. The dimeric, Ti–O–Ti bridged anhydride form of the di-TiIV-1,2-substituted α-Keggin polyoxotungstate, K10[α,α-P2W20Ti4O78]·12H2O 1, was unexpectedly found in the varied molar-ratio reactions of tri-lacunary precursor Na9[A-PW9O34]·19H2O with Ti(SO4)2 in aqueous solution. Although this compound was first found as a minor product in the preparation of the dimeric, tri-TiIV-1,2,3-substituted species, K10H2[α,α-P2W18Ti6O77]·17H2O 3, it was successfully prepared as a main product in this work and structurally characterized. Compound 1, as analytically pure, homogeneous colorless needle crystals, was obtained as a major product in 29.2% yield (2.7 g scale) from recrystallization under acidic conditions (at pH 2.2) of the 1 ∶ 2 molar-ratio reaction product. X-Ray structure analysis revealed that the molecular structure of 1 consisted of a dimeric anhydride formed by two Ti–O–Ti bonds linking two [α-1,2-PW10Ti2O40]7− Keggin units. Interestingly, ultracentrifugation molecular weight (MW) measurements of this compound in aqueous solution showed the pH-dependent interconversion between monomer [α-1,2-PW10Ti2O40]7−2 and dimer [α,α-P2W20Ti4O78]10−1; this compound was present as the monomer under less acidic conditions (pH 7.8), while it was in dimeric form under more acidic conditions (pH 1.0 and 2.2). Characterization of 1 was also accomplished by complete elemental analyses, TG/DTA, FTIR and solution (31P and 183W) NMR Spectroscopy.

  • A first example of polyoxotungstate-based giant molecule. Synthesis and molecular structure of a tetrapod-shaped Ti–O–Ti bridged anhydride form of Dawson tri-titanium(IV)-substituted polyoxotungstate
    Dalton Transactions, 2020
    Co-Authors: Yoshitaka Sakai, Chika Nozaki Kato, Kenji Yoza, Kenji Nomiya

    Abstract:

    The preparation and structural characterization of a giant “tetrapod”-shaped inorganic molecule, [(α-1,2,3-P2W15Ti3O60.5)4Cl]37− ,1a
    (abbreviated to {TiO6}12; FW ∼15700), consisting of four tri-TiIV-1,2,3-substituted α-Dawson substructures and one encapsulated Cl− ion, are described. A water-soluble, all-inorganic composition compound of the tetrameric Ti–O–Ti bridged anhydride form, NaxH33−xK4[1a]·yH2O, 1
    (x
    = 21–26, y
    = 60–70), being afforded by a stoichiometric reaction in aqueous solution of tri-lacunary Dawson polyoxotungstate Na12[B-α-P2W15O56]·19H2O with 3 equiv of Ti(SO4)2·4H2O in HCl-acidic aqueous solution followed by exchanging the countercation, was obtained as analytically pure, homogeneous colorless plate crystals. Single-crystal X-ray structure analysis revealed that the polyoxoanion 1a was an inorganic, giant “tetrapod”-shaped molecule (described as a sphere with a diameter of ∼31.2 A) with approximately Td symmetry. Characterization of 1 was also accomplished by complete elemental analysis, TG/DTA, FTIR, UV-vis absorption and solution (31P and 183W) NMR Spectroscopy.

  • Monomer and Dimer of Mono-titanium(IV)-Containing α-Keggin Polyoxometalates: Synthesis, Molecular Structures, and pH-Dependent Monomer—Dimer Interconversion in Solution.
    ChemInform, 2013
    Co-Authors: Yusuke Matsuki, Yuki Mouri, Yoshitaka Sakai, Satoshi Matsunaga, Kenji Nomiya

    Abstract:

    Compounds (III) and (IV) are characterized by single crystal XRD, FTIR, CPMAS 31P NMR, and solution 31P and 183W NMR Spectroscopy.

Yoshitaka Sakai – 2nd expert on this subject based on the ideXlab platform

  • A first example of polyoxotungstate-based giant molecule. Synthesis and molecular structure of a tetrapod-shaped Ti–O–Ti bridged anhydride form of Dawson tri-titanium(IV)-substituted polyoxotungstate
    Dalton Transactions, 2020
    Co-Authors: Yoshitaka Sakai, Chika Nozaki Kato, Kenji Yoza, Kenji Nomiya

    Abstract:

    The preparation and structural characterization of a giant “tetrapod”-shaped inorganic molecule, [(α-1,2,3-P2W15Ti3O60.5)4Cl]37− ,1a
    (abbreviated to {TiO6}12; FW ∼15700), consisting of four tri-TiIV-1,2,3-substituted α-Dawson substructures and one encapsulated Cl− ion, are described. A water-soluble, all-inorganic composition compound of the tetrameric Ti–O–Ti bridged anhydride form, NaxH33−xK4[1a]·yH2O, 1
    (x
    = 21–26, y
    = 60–70), being afforded by a stoichiometric reaction in aqueous solution of tri-lacunary Dawson polyoxotungstate Na12[B-α-P2W15O56]·19H2O with 3 equiv of Ti(SO4)2·4H2O in HCl-acidic aqueous solution followed by exchanging the countercation, was obtained as analytically pure, homogeneous colorless plate crystals. Single-crystal X-ray structure analysis revealed that the polyoxoanion 1a was an inorganic, giant “tetrapod”-shaped molecule (described as a sphere with a diameter of ∼31.2 A) with approximately Td symmetry. Characterization of 1 was also accomplished by complete elemental analysis, TG/DTA, FTIR, UV-vis absorption and solution (31P and 183W) NMR Spectroscopy.

  • Synthesis and pH-variable ultracentrifugation molecular weight measurements of the dimeric, Ti–O–Ti bridged anhydride form of a novel di-TiIV-1,2-substituted α-Keggin polyoxotungstate. Molecular structure of the [(α-1,2-PW10Ti2O39)2]10− polyoxoanion
    Journal of The Chemical Society-dalton Transactions, 2020
    Co-Authors: Kenji Nomiya, Yoshitaka Sakai, Mizuto Takahashi, Jason A. Widegren, Takao Aizawa, Noriko Chikaraishi Kasuga

    Abstract:

    The preparation and characterization of a Keggin-type, novel di-TiIV-1,2-substituted polyoxotungstate are described. The dimeric, Ti–O–Ti bridged anhydride form of the di-TiIV-1,2-substituted α-Keggin polyoxotungstate, K10[α,α-P2W20Ti4O78]·12H2O 1, was unexpectedly found in the varied molar-ratio reactions of tri-lacunary precursor Na9[A-PW9O34]·19H2O with Ti(SO4)2 in aqueous solution. Although this compound was first found as a minor product in the preparation of the dimeric, tri-TiIV-1,2,3-substituted species, K10H2[α,α-P2W18Ti6O77]·17H2O 3, it was successfully prepared as a main product in this work and structurally characterized. Compound 1, as analytically pure, homogeneous colorless needle crystals, was obtained as a major product in 29.2% yield (2.7 g scale) from recrystallization under acidic conditions (at pH 2.2) of the 1 ∶ 2 molar-ratio reaction product. X-Ray structure analysis revealed that the molecular structure of 1 consisted of a dimeric anhydride formed by two Ti–O–Ti bonds linking two [α-1,2-PW10Ti2O40]7− Keggin units. Interestingly, ultracentrifugation molecular weight (MW) measurements of this compound in aqueous solution showed the pH-dependent interconversion between monomer [α-1,2-PW10Ti2O40]7−2 and dimer [α,α-P2W20Ti4O78]10−1; this compound was present as the monomer under less acidic conditions (pH 7.8), while it was in dimeric form under more acidic conditions (pH 1.0 and 2.2). Characterization of 1 was also accomplished by complete elemental analyses, TG/DTA, FTIR and solution (31P and 183W) NMR Spectroscopy.

  • Monomer and Dimer of Mono-titanium(IV)-Containing α-Keggin Polyoxometalates: Synthesis, Molecular Structures, and pH-Dependent Monomer—Dimer Interconversion in Solution.
    ChemInform, 2013
    Co-Authors: Yusuke Matsuki, Yuki Mouri, Yoshitaka Sakai, Satoshi Matsunaga, Kenji Nomiya

    Abstract:

    Compounds (III) and (IV) are characterized by single crystal XRD, FTIR, CPMAS 31P NMR, and solution 31P and 183W NMR Spectroscopy.

René Thouvenot – 3rd expert on this subject based on the ideXlab platform

  • Aryldiazenido derivatives: A new entry to the functionalization of Keggin polyoxometalates
    Inorganica Chimica Acta, 2010
    Co-Authors: Carlos Bustos, René Thouvenot, Kamal Boubekeur, Anna Proust, Desmond Mac-leod Carey, Pierre Gouzerh

    Abstract:

    Abstract A series of aryldiazenido polyoxomolybdates of the type (nBu4N)2[Mo5O13(OMe)4(NNAr){Na(MeOH)}] (Ar = C6F5, 1; Ar = O2N-o-C6H4, 2; Ar = O2N-m-C6H4, 3; Ar = O2N-p-C6H4, 4a; Ar = (O2N)2-o,p-C6H3, 5) have been obtained by controlled degradation of the parent compounds (nBu4N)3[Mo6O18(NNAr)] with NaOH in methanol. They have been characterized by elemental analysis and UV–Vis and IR Spectroscopy. In addition, 4a has been characterized by 95Mo NMR Spectroscopy and the crystal structure of (nBu4N)2[Mo5O13(OMe)4(NNC6H4-p-NO2){Na(H2O))]·H2O (4b) has been determined by X-ray diffraction. The molecular structure of the anion of 4b features a lacunary Lindqvist-type anion [Mo5O13(OMe)4(NNC6H4-p-NO2)]3− interacting with a sodium cation through the four terminal axial oxygen atoms. The 1:1 sodium complexes react with BaCl2 and BiCl3 to yield 2:1 complexes which have been isolated as (nBu4N)4[Ba{Mo5O13(OMe)4(NNAr)}2] (Ar = C6F5, 6; Ar = O2N-p-C6H4, 7) and (nBu4N)3[Bi{Mo5O13(OMe)4(NNAr)}2] (Ar = C6F5, 8; Ar = O2N-p-C6H4, 9). X-ray crystallography analysis of 9·Me2CO has shown that the tetradentate [Mo5O13(OMe)4(N2C6H4-p-NO2)]3− anions provide a square-antiprismatic environment for Bi. In contrast, IR Spectroscopy provides evidence for a square-prismatic environment of Ba in 6 and 7. In acetonitrile–methanol mixed solvent, [Mo5O13(OMe)4(NNAr)]3− and [PW11O39]7−, generated in situ by alkaline degradation of their respective parents, [Mo6O18(NNAr)]3− and [PW12O40]3−, react together to give the Keggin-type diazenido compounds (nBu4N)4[PW11O39(MoNNAr)] (Ar = O2N-o-C6H4, 10; Ar = O2N-m-C6H4, 11; Ar = O2N-p-C6H4, 12), which have been characterized by 31P and 183W NMR Spectroscopy.

  • Synthesis and Spectroscopic Characterization of Organophosphono Derivatives of Lindqvist Niobotungstates – X‐ray Crystal Structures of (nBu4N)3[NbW10O38(RP)2] (R = nBu, Hep and Ph)
    European Journal of Inorganic Chemistry, 2008
    Co-Authors: Hafedh Driss, Kamal Boubekeur, Mongi Debbabi, René Thouvenot

    Abstract:

    A series of organophosphonopolyoxoniobotungstates [NbW10O38(RP)2]3– {R = Me (1), Et (2), Pr (3), nBu (4), Hex (5), Hep (6), Cy (7), Ph (8), All (9)} has been prepared by the reaction of (nBu4N)3[NbW5O19] with the appropriate organophosphono dichloride, RP(O)Cl2. All of the products were characterized by infrared and multinuclear (31P and 183W) NMR Spectroscopy. Compounds 4, 6 and 8 were characterized by single-crystal X-ray diffraction. The hybrid anions [NbW10O38(RP)2]3– are made up of two W5O18 subunits, which can be viewed as monovacant derivatives of the niobotungstate precursor linked by a {Nb(OPR)2} group.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

  • Synthesis and Characterization of the Keggin-Type Ruthenium-Nitrido Derivative [PW11O39{RuN}]4- and Evidence of Its Electrophilic Reactivity
    Journal of the American Chemical Society, 2007
    Co-Authors: Vanina Lahootun, René Thouvenot, Kamal Boubekeur, Claire Besson, Richard Villanneau, Francoise Villain, Lise-marie Chamoreau, Sébastien Blanchard, Anna Proust

    Abstract:

    The ruthenium-nitrido POM derivative [PW11O39{RuVIN}]4- has been synthesized by reaction between [PW11O39]7- and [RuVINCl5]2- or [RuVINCl4]-. Its molecular structure has been confirmed from multinuclear 31P and 183W NMR Spectroscopy together with an EXAFS study, while the oxidation state of the ruthenium bearing the nitrido ligand has been inferred both from 183W NMR and XANES analysis at the Ru-K edge. The potential of [PW11O39{RuVIN}]4- in N-atom transfer reactions has been demonstrated through reaction with triphenylphosphine, which ultimately leads to the release of the bis(triphenylphosphane)iminium cation [PPh3NPPh3]+ through several intermediates, among which the phosphoraniminato derivative [PW11O39{RuVNPh3}]3- has been structurally characterized. Its unusual oxidation state is in accordance with its EPR spectrum.