Kinetics and Catalysis

, Volume 41, Issue 3, pp 293–297 | Cite as

The role of triplet repulsion in alkyl radical addition to a 7π-C-O bond and alkoxy radical addition to a π-C-C bond

  • E. T. Denisov


The experimental activation energies of the R + O = CR1R2 and RO + CH2 = CHR1 addition reactions are analyzed within the framework of the parabolic model of the bimolecular addition reaction. The activation energy also depends on the dissociation energy of the forming C-O bond and on the reaction enthalpy: the higher the dissociation energy, the higher the activation energy. The empirical relationshipr e J..D e = 0.97 x 10-13 m kJ.-1 mol is found for H, Cl, Br and RO radical addition to multiple C=C and C=O bonds (re is the distance between the peaks of the intersecting parabolic curves). This is due to the effect of the triplet repulsion on radical addition. The interaction of polar groups and the steric effect also influence the activation energy.


Activation Energy Reaction Center Dissociation Energy Radical Addition Addition Reaction 
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  1. 1.
    Denisov, E.T.,Kinet. Katal., 1992, vol. 33, no. 1, p. 66.Google Scholar
  2. 2.
    Denisov, E.T.,Izv. Akad. Nauk, Ser. Khim, 1999, no. 3, p. 445.Google Scholar
  3. 3.
    Denisov, E.T.,Khim. Fiz., 1998, vol. 17, no. 11, p. 83.Google Scholar
  4. 4.
    Denisov, E.T.,Kinet. Katal., 1994, vol. 35, no. 5, p. 671.Google Scholar
  5. 5.
    Denisov, E.T.,Usp. Khim., 1997, vol. 66, no. 10, p. 953.Google Scholar
  6. 6.
    Lias, S.G., Liebman, J.F., Levin, R.D., and Kafafi, S.A.,NIST Positive Ion Energetics, version 2.0, Geithersburg: Department of Commerce, 1993.Google Scholar
  7. 7.
    Tsang, W.,Energetics of Free Radicals, Greenberg, A. and Liebman, J.., Eds., New York: Blackie Academic and Professional, 1996, p. 22.Google Scholar
  8. 8.
    Denisov, E.T.,Zh. Fiz. Khim., 1993, vol. 67, no. 12, p. 2416.Google Scholar
  9. 9.
    Denisov, E.T.,Zh. Fiz. Khim., 1994, vol. 68, no. 1, p. 29.Google Scholar
  10. 10.
    Landolt-Bornstein Numerical Data and Functional Relationships in Science and Technology, Berlin: Springer-Verlag, 1984, vol. 13.Google Scholar
  11. 11.
    Walling, C. and Thaler, W.,J. Am. Chem. Soc, 1961, vol. 83, no. 18, p. 3877.CrossRefGoogle Scholar
  12. 12.
    Shelton, J.R. and Uzelmier, C.W.,J. Org. Chem., 1970, vol. 35, no. 5, p. 1576.CrossRefGoogle Scholar
  13. 13.
    Walling, C. and Clark, R.T.,J. Am. Chem. Soc, 1974, vol. 96, no. 14, p. 4530.CrossRefGoogle Scholar
  14. 14.
    Pliss, E.M., Mishustin, V.I., and Pliss, R.E.,Second Int. Symp. “Free Radical Polymerization: Kinetics and Mechanism,” Santa Margherita, 1996, p. 327.Google Scholar
  15. 15.
    Korth, H.G., Chateaneuf, J., Lusztyk, J., and Ingold, K.U.,J. Org. Chem., 1991, no. 7, p. 2405.Google Scholar
  16. 16.
    Knoll, H., Richter, G., and Schliebs, R.,Int. J. Chem. Kinet., 1980, vol. 12, p. 623.CrossRefGoogle Scholar
  17. 17.
    Heilman, W.J., Remboum, A., and Szwarc, M.,J. Chem. Soc, 1957, no. 3, p. 1127.Google Scholar
  18. 18.
    Levy, M. and Szwarc, M.,J. Am. Chem. Soc, 1955, vol. 77, no. 7, p. 1949.CrossRefGoogle Scholar
  19. 19.
    Smid, J. and Szwarc, M.,J. Am. Chem. Soc, 1956, vol. 78, no. 14, p. 3322.CrossRefGoogle Scholar
  20. 20.
    Remboum, A. and Szwarc, M.,J. Am. Chem. Soc, 1955, vol. 77, no. 17, p. 4468.CrossRefGoogle Scholar
  21. 21.
    Comprehensive Chemical Kinetics, Bamford, C.H. and Tipper, C.F.H., Eds., Amsterdam: Elsevier, 1976, vol. 14, p. 153.Google Scholar
  22. 22.
    Denisova, T.G. and Denisov, E.T.,Neflekhimiya, 1998, vol. 38, no. 1, p. 15.Google Scholar

Copyright information

© MAIK “Nauka/Interperiodica” 2000

Authors and Affiliations

  • E. T. Denisov
    • 1
  1. 1.Institute of Problems of Chemical PhysicsRussian Academy of SciencesMoscow oblastRussia

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