Research on Chemical Intermediates

, Volume 22, Issue 8, pp 725–735 | Cite as

NMR isotope shifts in the 2-methyl-2-bicyclo[2.1.1]hexyl cation and related systems

  • David A. Forsyth
  • Chitchanun Panyachotipun
Article
  • 20 Downloads

Abstract

NMR isotope shifts at 13C nuclei due to deuteriation in the 2-methyl-2-bicyclo[2.1.1]hexyl cation are reported. Comparisons are made to the 2-methyl-2-bicyclo[2.2.1]heptyl and 2-methyl-2-bicyclo[2.2.2]octyl cations, and also to neutral molecules containing the bicyclo[2.1.1]hexyl framework. The combination of isotope effects with temperature dependence of 13C chemical shifts allows predictions of the shapes of the energy surfaces along the bending coordinate corresponding to bridging in these cations.

Keywords

Chemical Shift Isotope Effect Isotope Shift Upfield Shift Heptyl 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    K. L. Servis, and F. F. Shue, J. Am. Chem. Soc., 102, 7233 (1980).CrossRefGoogle Scholar
  2. 2.
    D. A. Forsyth, J. H. Botkin, J. S. Puckace, K. L. Servis, and R. L. Domenick, J. Am. Chem. Soc., 109, 7270 (1987).CrossRefGoogle Scholar
  3. 3.
    D. A. Forsyth, and J. H. Botkin, J. Am. Chem. Soc., 106, 4296 (1984).CrossRefGoogle Scholar
  4. 4.
    K. L. Servis, R. L. Domenick, D. A. Forsyth, and Y. Pan, J. Am. Chem. Soc., 109, 7263 (1987).CrossRefGoogle Scholar
  5. 5.
    D. A. Forsyth, and C. Panyachotipun, J. Chem. Soc., Chem. Commun., 1564 (1988).Google Scholar
  6. 6.
    K. L. Servis, E. V. Koh, and P. Baine, Croatica Chem. Acta, 65, 679 (1992).Google Scholar
  7. 7.
    G. A. Olah, G. Liang, S. P. Jindal, J. Am. Chem. Soc., 98, 2508 (1976).CrossRefGoogle Scholar
  8. 8.
    E. W. Della, P. E. Pigou, Aust. J. Chem., 36, 2261 (1983).Google Scholar
  9. 9.
    W. Kirmse, V. Zellmer, B. Goer, J. Am. Chem. Soc., 108, 4912 (1986).CrossRefGoogle Scholar
  10. 10.
    For reviews of isotope shifts, see: (a) P. E. Hansen, Annu. Rep. NMR Spectrosc., 15, 106 (1983). (b) D. A. Forsyth, Isot. Org. Chem., 6, 1 (1984). (c) C. J. Jameson, and H. J. Osten, Annu. Rep. NMR Spectrosc., 17, 1 (1986). (d) H. U. Siehl, Adv. Phys. Org. Chem., 23, 63 (1987). (e) P. E. Hansen, Progr. NMR Spectrosc., 20, 207 (1988). (f) S. Berger, NMR Basic Principles and Progress, 22, 1 (1990).Google Scholar
  11. 11. (a)
    G. A. Olah, A. M. White, J. R. DeMember, A. Commeyras, and C. Y. Lui, J. Am. Chem. Soc., 84, 977 (1962). (b) G. A. Olah, Acc. Chem. Res., 9, 41 (1976). (c) P. v. R. Schleyer, D. Lenoir, P. Mison, G. Liang, G. K. S. Prakash, G. A. Olah, J. Am. Chem. Soc., 102, 683 (1980) and references therein.CrossRefGoogle Scholar
  12. 12. (a)
    M. Saunders, L. Telkowski, and M. R. Kates, J. Am. Chem. Soc., 99, 8070 (1977). (b) M. Saunders, and M. R. Kates, J. Am. Chem. Soc., 99, 8071 (1977). (c) M. Saunders, M. R. Kates, K. B. Wiberg, and W. Pratt, J. Am. Chem. Soc., 99, 8072 (1977).CrossRefGoogle Scholar
  13. 13.
    D. A. Forsyth, C. Panyachotipun, Y. Pan, A. M. Moussa, and A.-H. A. Youssef, J. Org. Chem., 55, 5375 (1990).CrossRefGoogle Scholar
  14. 14.
    P. v. R. Schleyer, J. W. de M. Carneiro, W. Koch, and D. A. Forsyth, J. Am. Chem. Soc., 113, 3990 (1991).CrossRefGoogle Scholar

Copyright information

© Springer 1996

Authors and Affiliations

  • David A. Forsyth
    • 1
  • Chitchanun Panyachotipun
    • 1
  1. 1.Department of ChemistryNortheastern UniversityBoston

Personalised recommendations