Skip to main content
Log in

Reduced parabolic model for radical addition reactions

  • Published:
Russian Chemical Bulletin Aims and scope

Abstract

The transition state of addition of free radicals and atoms to multiple bonds is considered as a result of intersecting of two parabolic potential curves. One of them characterizes the stretching vibration of the attacked multiple bond, and another curve characterizes the stretching vibration of the bond formed in the transition state. The force constant of the latter is calculated by an empirical equation that correlates the force constant with the bond dissociation energy. In the framework of this model, the thermally neutral activation energy (E e0) and the elongation of the attacked and formed bonds (r e) in the transition state were calculated from the experimental data (activation energy (E e) and enthalpy of reaction (ΔH e)) for the addition of an H atom and methyl, alkoxyl, aminyl, triethylsilyl, and peroxyl radicals to the C=C bond and the addition of H• and •CH3 to the C=O and C≡C bonds. Analysis of the data obtained showed that E e0 depends linearly on the |ΔH e| + Ee sum, i.e., Ee0/kJ mol−1 = 14.2 + 0.61 · (Ee − ΔH e), and the bond elongation in the transition state for addition of the most part of radicals to ethylene and acetylene vary within (0.65–0.87)·10−10 m. The factors affecting the activation energy of the radical addition reactions are discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. E. T. Denisov (1992) Kinet. Katal. 33 66

    Google Scholar 

  2. E. T. Denisov T. G. Denisova (1998) Khim. Fiz. 17 83

    Google Scholar 

  3. E. T. Denisov T. G. Denisova (1998) Neftekhimiya 38 15

    Google Scholar 

  4. E. T. Denisov, Izv. Akad. Nauk, Ser. Khim., 1999, 445 [Russ. Chem. Bull., 1999, 48, 442 (Engl. Transl.)].

  5. E. T. Denisov (1999) Kinet. Katal. 40 835

    Google Scholar 

  6. E. T. Denisov (1999) NoChapterTitle Z. B. Alfassi (Eds) General Aspects of the Chemistry of Radicals Wiley New York 79

    Google Scholar 

  7. E. T. Denisov (2000) Kinet. Katal. 41 325

    Google Scholar 

  8. E. T. Denisov (2001) Kinet. Katal. 42 30

    Google Scholar 

  9. E. T. Denisov (2000) Usp. Khim. 69 166

    Google Scholar 

  10. E. T. Denisov T. G. Denisova T. S. Pokidova (2003) Handbook of Free Radical Initiators Wiley New York

    Google Scholar 

  11. J. A. Kerr M. J. Parsonage (1972) Evaluated Kinetic Data on Gas Phase Addition Reactions. Reactions of Atoms and Radicals with Alkenes, Alkynes, and Aromatic Compounds Butterworth London

    Google Scholar 

  12. W. Tsang R. F. Hampson (1986) J. Phys. Chem. Ref. Data 15 1087

    Google Scholar 

  13. P. D. Lightfooz M. J. Pilling (1987) J. Phys. Chem. 91 3373

    Google Scholar 

  14. J. K. Thomas (1967) J. Phys. Chem. 71 1919

    Google Scholar 

  15. P. Netta R. W. Fessenden R. H. Schuler (1971) J. Phys. Chem. 75 1654

    Google Scholar 

  16. J. Munk P. Pagsberg E. Ratajczak A. Sillensen (1986) J. Phys. Chem. Lett. 132 417

    Google Scholar 

  17. A. F. Dodonov G. K. Lavrovskaya V. L. Tal’roze (1969) Kinet. Katal. 10 22

    Google Scholar 

  18. W. Braun and M. Lenzi, Disc. Faraday Soc., 1967, 252.

  19. T. J. Hardwick (1962) J. Phys. Chem. 66 291

    Google Scholar 

  20. E. E. Daby H. Niki B. Weinstock (1971) J. Phys. Chem. 75 1601

    Google Scholar 

  21. T. Soylemez R. H. Schuler (1974) J. Phys. Chem. 78 1052

    Google Scholar 

  22. B. D. Michael E. J. Hart (1970) J. Phys. Chem. 74 2878

    Google Scholar 

  23. K. N. Jha G. R. Freeman (1973) J. Am. Chem. Soc. 95 5891

    Google Scholar 

  24. R. R. Hents D. J. Milner (1968) J. Chem. Phys. 49 2155

    Google Scholar 

  25. G. V. Buxton C. L. Greenstock W. P. Helman A. B. Ross (1988) J. Phys. Chem. Ref. Data 17 513

    Google Scholar 

  26. T. Zytowski H. Fischer (1996) J. Am. Chem. Soc. 118 437

    Google Scholar 

  27. NIST Standard Reference Database 17, NIST Chemical Kinetics Database — Version 6.0, Gaithersburg, 1994.

  28. M. Gazith M. Szwarc (1957) J. Am. Chem. Soc. 79 3339

    Google Scholar 

  29. J. Gresser A. Rajbenbach M. Szwarc (1961) J. Am. Chem. Soc. 83 3005

    Google Scholar 

  30. V. P. Sass S. I. Serov (1977) Zh. Org. Khim. 13 2298

    Google Scholar 

  31. L. Herk A. Stefani M. Szwarc (1961) J. Am. Chem. Soc. 83 3008

    Google Scholar 

  32. A. Rajbenbach M. Szwarc (1957) J. Am. Chem. Soc. 79 6343

    Google Scholar 

  33. E. T. Denisov T. G. Denisova (2000) Handbook of Antioxidants CRS Press Boca Raton

    Google Scholar 

  34. L. Pauling (1970) General Chemistry Freeman and Co. San-Francisco

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1542–August, 2004.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Denisov, E.T. Reduced parabolic model for radical addition reactions. Russ Chem Bull 53, 1602–1608 (2004). https://doi.org/10.1007/s11172-005-0003-3

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11172-005-0003-3

Key words

Navigation