Abstract
The scrambling of carbon atoms in gaseous carbocations is readily explicable by invoking transition states or intermediates of pyramidal structure, which are now be seen as the logical bridge between organic and organometallic chemistry. The electronic structure of this species is treated with respect to some of their physical and chemical properties (energy, charge distribution, geometry). Specific examples discussed include the following hydrocarbon ions, the gas phase chemistry of which proceeds via pyramidal intermediates: C5H5+ C5H9+ C5H11+, C5H5+. Reasons are provided why, in contrast, the carbon scrambling in some other systems, as for example tropylium ion ⇄ benzyl cation, does not involve pyramidal cations but proceeds via a sequence of orbital symmetry allowed isomerization, or why in the case of simple saturated hydrocarbon ions, as for example C4H9+, the C-skeleton reorganization is achieved by the well-known Wagner/Meerwein type rearrangement. The carbon scrambling in ionised cyclopentadiene, which precedes the formation of aliene cation radical and acetylene, is due to the intermediacy of ionised bicyclo[2.1. 0]pent-2-ene, a species which is also involved in the phototransposition of carbon atoms in neutral cyclopentadiene. Pyramidal-like structures are much too high in energy to play a role in the degenerate isomer ization of C5H6+.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Hogeveen, H., and Kwant, P.W.: 1975, Acc. Chem. Res. 8, p. 413.
Stohrer, W.D., and Hoffmann, R.: 1972, J. Am. Chem. Soc. 94, p. 1661.
Masamune, S.: 1975, Pure Appl. Chem. 44, p. 861.
Schwarz, H.: 1981, Angew. Chem. Int. Ed. Engl. 20, p. 991.
Wade, K.: 1975, Chem. Br. 11, p. 177.
Williams, R. E.: 1971, Inorg. Chem. 10, p. 210.
Rudolph, R.W.: 1976, Acc. Chem. Res. 9, p. 446.
Balaban, A. T., and Rouvray, D. H.: 1980, Tetrahedron 36, p. 1851.
Grimes, R. N.: 1970, Carbaboranes, Academic Press, New York.
Lipscomb, W. N.: 1973, Acc. Chem. Res. 7, p. 257.
Jemmis, E. D., and Schleyer, P. v. R.: 1982, J. Am. Chem. Soc., in the press.
Jonkman, H. T., and Nieuwport, W. C.: 1973, Tetrahedron Lett., p. 1671.
Elian, M., and Hoffmann, R.: 1975, Inorg. Chem. 14, p. 1058.
Cone, C., Dewar, M. J. S., and Landman, D.: 1977, J. Am. Chem. Soc. 99, p. 372.
Rinchardt, K. L. Jr., Buchholz, A. C., van Lear, G. E., and Cantrill, H. L.: 1968, J. Am. Chem. Soc. 90, p. 2983.
Davidson, R.A., and Skell, P.S.: 1973, J. Am. Chem. Soc. 95, p. 6843.
McLafferty, F.W., and Winkler, J.: 1974, J. Am. Chem. Soc. 96, p. 5182.
Thies, H., and Schwarz, H.: unpublished results
Dewar, M.J.S., and Haddon, R. C.: 1973, J. Am. Chem. Soc. 95, p. 5836.
Olah, G.A., Prakash, G. K. S., Liang, G., Westerman, P. W., Kunde, K., Chandrasekhar, J., and Schleyer, P. v. R.: 1980, J. Am. Chem. Soc. 102, p. 4485.
Hehre, W. J., Schleyer, P. v. R.: 1973, J. Am. Chem. Soc. 95, p. 5837.
Thies, H., and Schwarz, H.: manuscript in preparation.
Franke, W., Schwarz, H., Thies, H., Chandrasekhar, J., Schleyer, P. V.R., Hehre, W. J., Saunders, M., and Walker, G.: 1981, Chem. Ber. 114, p. 2808.
Franke, W., Frenking, G., Schwarz, H., and Wolfschütz, R.: 1981, Chem. Ber. 114, p. 3878.
Saunders, M., Vogel, P., Hagen, E. L., and Rosenfeld, J.: 1973, Acc. Chem. Res. 6, p. 53.
Schwarz, H., Franke, W., Chandrasekhar, J., and Schleyer, P. v. R.: 1979, Tetrahedron 35, p. 1969.
Speranza, M.: 1980, Tetrahedron Lett., p. 1983.
Dill, J.D., Schleyer, P.v.R., Binkley, J. S., Seeger, R., Pople, J.A., and Haselbach, E.: 1976, J. Am. Chem. Soc. 98, p. 5428.
Tasaka, M., Ogata, M., and Ichikawa, H.: 1981, J. Am. Chem. Soc. 103, p. 1885.
Dicinson, R., and Williams, D.H.: 1971, J. Chem. Soc. B, p. 249.
Thies, H., Halim, H., and Schwarz, H.: manuscript in preparation.
Andrews, G.D., and Baldwin, J. E.: 1977, J. Am. Chem. Soc. 99, p. 4851.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1984 D. Reidel Publishing Company, Dordrecht, Holland
About this chapter
Cite this chapter
Schwarz, H., Thies, H., Franke, W. (1984). Carbon Skeletal Rearrangements Via Pyramidal Carbocations. In: Almoster Ferreira, M.A. (eds) Ionic Processes in the Gas Phase. NATO ASI Series, vol 118. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-7248-3_14
Download citation
DOI: https://doi.org/10.1007/978-94-009-7248-3_14
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-009-7250-6
Online ISBN: 978-94-009-7248-3
eBook Packages: Springer Book Archive