Vibrational spectra and structures of the anions of urazole and 4-methylurazole: DFT calculations of the normal modes and the influence of hydrogen bonding

John P. Ryall, Trevor J. Dines, Babur Z. Chowdhry, Stephen A. Leharne, Robert Withnall

    Research output: Contribution to journalArticle

    4 Citations (Scopus)

    Abstract

    Solid state IR and Raman as well as aqueous solution state Raman spectra are reported for the anions of urazole and 4-methylurazole, and their N-deuterated derivatives. DFT calculations, at the B3-LYP/cc-pVTZ level, established that the structures and vibrational spectra of both anions can be interpreted using a model that incorporates hydrogen-bonded water molecules, in conjunction with the polarizable continuum solvation method. In the case of the urazole anion it is shown that deprotonation occurs primarily at N1 rather than N4, but there is also evidence for the second tautomer both in the solid state and in aqueous solution. The vibrational spectra were computed at the optimised molecular geometry in each case, enabling normal coordinate analysis, which yielded satisfactory agreement with the experimental IR and Raman data. Computed potential energy distributions of the normal modes provided detailed vibrational assignments. (C) 2010 Elsevier B.V. All rights reserved.

    Original languageEnglish
    Pages (from-to)918-925
    Number of pages8
    JournalSpectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
    Volume78
    Issue number3
    DOIs
    Publication statusPublished - Mar 2011

    Keywords

    • IR
    • Raman
    • DFT
    • Urazole
    • 4-Methylurazole
    • Anions
    • Hydrogen bonding
    • SUBSTITUTED URAZOLES
    • CHEMISTRY
    • ENERGIES
    • DENSITY
    • PROTON

    Cite this

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    title = "Vibrational spectra and structures of the anions of urazole and 4-methylurazole: DFT calculations of the normal modes and the influence of hydrogen bonding",
    abstract = "Solid state IR and Raman as well as aqueous solution state Raman spectra are reported for the anions of urazole and 4-methylurazole, and their N-deuterated derivatives. DFT calculations, at the B3-LYP/cc-pVTZ level, established that the structures and vibrational spectra of both anions can be interpreted using a model that incorporates hydrogen-bonded water molecules, in conjunction with the polarizable continuum solvation method. In the case of the urazole anion it is shown that deprotonation occurs primarily at N1 rather than N4, but there is also evidence for the second tautomer both in the solid state and in aqueous solution. The vibrational spectra were computed at the optimised molecular geometry in each case, enabling normal coordinate analysis, which yielded satisfactory agreement with the experimental IR and Raman data. Computed potential energy distributions of the normal modes provided detailed vibrational assignments. (C) 2010 Elsevier B.V. All rights reserved.",
    keywords = "IR, Raman, DFT, Urazole, 4-Methylurazole, Anions, Hydrogen bonding, SUBSTITUTED URAZOLES, CHEMISTRY, ENERGIES, DENSITY, PROTON",
    author = "Ryall, {John P.} and Dines, {Trevor J.} and Chowdhry, {Babur Z.} and Leharne, {Stephen A.} and Robert Withnall",
    year = "2011",
    month = "3",
    doi = "10.1016/j.saa.2010.10.028",
    language = "English",
    volume = "78",
    pages = "918--925",
    journal = "Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy",
    issn = "1386-1425",
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    }

    Vibrational spectra and structures of the anions of urazole and 4-methylurazole : DFT calculations of the normal modes and the influence of hydrogen bonding. / Ryall, John P.; Dines, Trevor J.; Chowdhry, Babur Z.; Leharne, Stephen A.; Withnall, Robert.

    In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Vol. 78, No. 3, 03.2011, p. 918-925.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Vibrational spectra and structures of the anions of urazole and 4-methylurazole

    T2 - DFT calculations of the normal modes and the influence of hydrogen bonding

    AU - Ryall, John P.

    AU - Dines, Trevor J.

    AU - Chowdhry, Babur Z.

    AU - Leharne, Stephen A.

    AU - Withnall, Robert

    PY - 2011/3

    Y1 - 2011/3

    N2 - Solid state IR and Raman as well as aqueous solution state Raman spectra are reported for the anions of urazole and 4-methylurazole, and their N-deuterated derivatives. DFT calculations, at the B3-LYP/cc-pVTZ level, established that the structures and vibrational spectra of both anions can be interpreted using a model that incorporates hydrogen-bonded water molecules, in conjunction with the polarizable continuum solvation method. In the case of the urazole anion it is shown that deprotonation occurs primarily at N1 rather than N4, but there is also evidence for the second tautomer both in the solid state and in aqueous solution. The vibrational spectra were computed at the optimised molecular geometry in each case, enabling normal coordinate analysis, which yielded satisfactory agreement with the experimental IR and Raman data. Computed potential energy distributions of the normal modes provided detailed vibrational assignments. (C) 2010 Elsevier B.V. All rights reserved.

    AB - Solid state IR and Raman as well as aqueous solution state Raman spectra are reported for the anions of urazole and 4-methylurazole, and their N-deuterated derivatives. DFT calculations, at the B3-LYP/cc-pVTZ level, established that the structures and vibrational spectra of both anions can be interpreted using a model that incorporates hydrogen-bonded water molecules, in conjunction with the polarizable continuum solvation method. In the case of the urazole anion it is shown that deprotonation occurs primarily at N1 rather than N4, but there is also evidence for the second tautomer both in the solid state and in aqueous solution. The vibrational spectra were computed at the optimised molecular geometry in each case, enabling normal coordinate analysis, which yielded satisfactory agreement with the experimental IR and Raman data. Computed potential energy distributions of the normal modes provided detailed vibrational assignments. (C) 2010 Elsevier B.V. All rights reserved.

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    KW - 4-Methylurazole

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    KW - Hydrogen bonding

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    KW - CHEMISTRY

    KW - ENERGIES

    KW - DENSITY

    KW - PROTON

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    JO - Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

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