View PDF Version
 
DOI: 10.1039/A708165K (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1998, 857-862

PM3 and ab initio studies of the C8H8 potential energy surface. Thermal isomerism of syn- and anti-tricyclo[4.2.0.02,5]octa-3,7-dienes[hair space]†

(Note: The full text of this document is currently only available in the PDF Version )

Carlota Conesa and Henry S. Rzepa

Abstract

We have identified for the first time symmetry allowed pathways for rearrangement of both the syn (1) and anti (2) isomers of the cyclobutadiene dimer in the closed shell potential energy surface for the isomerisation to cyclooctatetraene. At the B3LYP/6-31G(d) level of theory, the calculated activation energy for the reaction of 1 is 3.2 kcal mol–1 lower than that for 2, in good agreement with the experimental difference of 3.6 kcal mol–1. The possible influence of the σ strain on the synchronicity of the pericyclic reactions of the systems is discussed.

References

  1. For a review see J. J. Gajewski, Hydrocarbon Thermal Isomerizations, Academic Press, 1981 Search PubMed; G. I. Fray, R. G. Saxton, The chemistry of cyclooctatetraene and its derivatives, Cambridge University Press, 1978 Search PubMed.
  2. R. Willstätter and E. Waser, Ber. Dstch. Chem. Ges., 1911, 44, 3423 Search PubMed.
  3. M. Avram, Gh. Mateescu, I. G. Dinulescu, E. Marica and C. D. Nenitzescu, Tetrahedron Lett., 1961, 21 CrossRef CAS.
  4. M. Avram, I. G. Dinulescu, E. Marica, G. Mateesu, E. Sliam and C. D. Nenitzescu, Chem. Ber., 1964, 97, 382 CAS.
  5. R. S. Case, M. J. S. Dewar, S. Kirschner, R. Pettit and W. Slegeir, J. Am. Chem. Soc., 1974, 7581 CrossRef CAS.
  6. H. M. Frey, H.-D. Martin and M. Hekman, J. Chem. Soc., Chem. Commun., 1975, 204 RSC.
  7. H. S. Rzepa, P. Molina, M. Alajarin and A. Vidal, Tetrahedron, 1992, 7425 CrossRef CAS.
  8. S. Shaik, A. Shurki, D. Danovich and P. C. Hiberty, J. Am. Chem. Soc., 1996, 118, 666 CrossRef CAS; P. C. Hiberty, D. Danovich, A. Shurki and S. Shaik, J. Am. Chem. Soc., 1995, 117, 7760 CrossRef.
  9. J. J. P. Stewart, MOPAC, Quantum Chemistry Program Exchange, University of Indiana, Bloomington, USA, Program 455 Search PubMed.
  10. J. Baker, F. Jensen, H. S. Rzepa and A. Stebbings, Quantum Chemistry Program Exchange Bulletin, 1990, 10, 76 Search PubMed.
  11. Gaussian program systems available from Gaussian Inc., Carnegie Office Park, Building 6, Pittsburgh, PA, USA.
  12. H. B. Schlegel, J. Comput. Chem., 1982, 3, 214 CrossRef CAS.
  13. C. Peng and H. B. Schlegel, Isr. J. Chem., 1993, 33, 449 CAS.
  14. M. J. S. Dewar and K. M. Merz Jr., J. Chem. Soc., Chem. Commun., 1985, 343 RSC.
  15. P. v. R. Schleyer, C. Maerker, A. Dransfeld, H. Jiao and N. J. R. v. E. Hommes, J. Am. Chem. Soc., 1996, 118, 6317 CrossRef CAS.
  16. GIAO-HF/6-31G(d)//B3LYP/6-31 G(d).
  17. (a) H. Iwamura and K. Morio, Bull. Chem. Jpn., 1972, 45, 3599 Search PubMed; (b) H.-D. Martin, T. Urbanek and R. Walsh, J. Am. Chem. Soc., 1985, 107, 5533; (c) H.-D. Martin, T. Urbanek, P. Pföhler and R. Walsh, J. Chem. Soc., Chem. Commun., 1985, 964 RSC.
  18. Patent, Chem. Werke Huels; DE 1240518, 1964; Chem. Abstr., 68, 77694r Search PubMed.
  19. P. G. Wenthold, D. A. Hrovat, W. T. Borden and W. C. Lineberger, Science, 1996, 272, 1456 CAS; D. A. Hrovat and W. T. Borden, J. Am. Chem. Soc., 1992, 114, 5879 CrossRef CAS; L. A. Paquette, M. P. Trova, J. Luo, A. E. Clough and L. B. Anderson, J. Am. Chem. Soc., 1990, 112, 228 CrossRef CAS.
  20. T. Mukai and Y. Yamashita, Tetrahedron Lett., 1978, 357 CrossRef CAS.
  21. R. C. Bingham and M. J. S. Dewar, J. Am. Chem. Soc., 1975, 97, 1294 CrossRef CAS.
Click here to see how this site uses Cookies. View our privacy policy here.