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DOI: 10.1039/A901511F (Paper) Reference Section for: J. Mater. Chem., 1999, 9, 1819-1824

Solid state 2H NMR study of the orientation and dynamics of cobaltocenium intercalated in the layered silicate LaponiteRD

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Stephen O'Brien, Jonathan Tudor and Dermot O'Hare

Abstract

Ion-exchange intercalation of [Co(η-C5D5)2]+ ions in the smectite clay LaponiteRD [Na0.46Mg5.42Li0.46Si8(OH)4O20] yields [Mg5.42Li0.46Si8(OH)4O20{Co(η-C5D5)2}0.4Na0.1]. Structural and dynamic information about the material was obtained with the benefit of 2H NMR spectroscopic measurements, performed on powder and specially prepared oriented samples, combined with comparisons to 2H NMR lineshape simulations. The cobaltocenium cations adopt an ordered arrangement in the host lattice with their principal molecular axes parallel to the silicate layers. In addition to rotation about the principal molecular axis, previously observed for similar cobaltocenium layered intercalates, the emergence of an inner component with a splitting of 22.3 kHz over the temperature range 220-300 K strongly suggests the molecule is undergoing n-fold reorientations about the C2 axis of symmetry. Concurrent to this dynamic motion is an additional vibrational motion in and out of the plane parallel to the silicate layers. Coupled with rotation about the C2 axis, this gives rise to a gyratory motion in the slow-intermediate regime which increases with temperature until the fast regime is reached at 330 K.

References

  1. P. Cool and E. F. Vansant, Microporous Mater., 1996, 6, 27 CrossRef CAS.
  2. J. M. Corker, J. Evans and J. M. Rummey, Mater. Chem. Phys., 1991, 29, 201 CAS.
  3. Laporte Absorbents, Laporte Technical Bulletin, L104 A Search PubMed.
  4. C. Grey, D. O'Hare, J. S. O. Evans and S. J. Heyes, J. Chem. Soc., Chem. Commun., 1991, 1380 RSC.
  5. S. J. Mason, D. Phil. Thesis, Oxford, 1993.
  6. S. J. Mason, S. J. Heyes and D. O'Hare, J. Chem. Soc., Chem. Commun., 1995, 1657 RSC.
  7. D. O'Hare, J. S. O. Evans, P. A. Turner, S. Mason, S. J. Heyes and J. Greenwood, J. Mater. Chem., 1995, 5, 1383 RSC.
  8. J. H. Davis, K. R. Jeffrey, M. Bloom and M. I. V. P. Higgs, Chem. Phys. Lett., 1976, 42, 390 CrossRef CAS.
  9. M. Bloom, J. H. Davis and M. I. Valic, Can. J. Phys., 1980, 58, 1510 CAS.
  10. R. Hentschel and H. W. Speiss, J. Magn. Reson., 1979, 35, 157 CAS.
  11. A. D. Ronemus, R. L. Vold and R. R. Vold, J. Magn. Reson., 1986, 70, 416 CAS.
  12. D. W. Bruce and D. O'Hare, Inorganic Materials, John Wiley & Sons Ltd, 2nd edn., 1996 Search PubMed.
  13. H.-V. Wong, J. S. O. Evans, S. Barlow, S. J. Mason and D. O'Hare, Inorg. Chem., 1994, 25, 5515 CrossRef.
  14. D. O'Hare, Chem. Rev., 1992, 21, 121 CrossRef CAS.
  15. P. L. Olympia, I. Y. Wei and B. M. Fung, J. Chem. Phys., 1969, 51, 1610 CAS.
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