Elucidation of Structure and Dynamics in Solid Octafluoronaphthalene from Combined NMR, Diffraction, And Molecular Dynamics Studies.
X-ray diffraction (XRD), molecular dynamics simulations (MD), and F NMR have been used to investigate structure and dynamics in solid octafluoronaphthalene, CF. Two distinct processes are observed via measurements of F relaxation times as a function of temperature; a faster process from T relaxation...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 14; pp. 5179 - 5186 |
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| Autores principales: | , , , , |
| Formato: | Artículo |
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American Chemical Society
4/14/2010
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=50249930&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 50249930 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 4/14/2010 vid: 132 iid: 14 pid: 997 pub: American Chemical Society artinfo: ui: 50249930 10.1021/ja910526z ppf: 5179 ppct: 7 formats: tig: atl: Elucidation of Structure and Dynamics in Solid Octafluoronaphthalene from Combined NMR, Diffraction, And Molecular Dynamics Studies. aug: au: Ilott, Andrew J. Palucha, Sebastian Batsanov, Andrei S. Wilson, Mark R. Hodgkinson, Paul affil: Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom su: Naphthalene Molecular dynamics X-ray diffraction Nuclear magnetic resonance Optical diffraction sug: subj: Naphthalene Molecular dynamics X-ray diffraction Nuclear magnetic resonance Optical diffraction ab: X-ray diffraction (XRD), molecular dynamics simulations (MD), and F NMR have been used to investigate structure and dynamics in solid octafluoronaphthalene, CF. Two distinct processes are observed via measurements of F relaxation times as a function of temperature; a faster process from T relaxation with a correlation time of the order of ns at ambient temperature (fitting to Arrhenius-type parameters E = 20.6 ± 0.4 kJ mol and τ = 8 ± 1 x 10 s) and a much slower process from T relaxation with a correlation time of the order of µs (fitting to E = 55.1 ± 1.3 kJ mol and τ = 4 ± 2 x 10 s). Atomistic molecular dynamics reveals the faster process to involve a small angle jump of 40° of the molecules, which is in perfect agreement with the X-ray diffraction study of the material at ambient temperature. The MD study reveals the existence of more extreme rotations of the molecules, which are proposed to enable the full rotation of the octafluoronaphthalene molecules. This explains both the Tip results and previous wide-line F NMR studies. The experimental measurements (NMR and XRD) and the MD computations are found to be strongly complementary and mutally essential. The reasons why a process on the time scale of microseconds, and associated with such a large activation barrier, can be accessed via classical molecular dynamics simulations are also discussed. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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