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Should bond-formation lag behind bond-cleavage in radical-exchange reactions?

  • Asish K Chandra
Physical And Theoretical
  • 10 Downloads

Abstract

A few simple concerted radical-exchange reactions (A + BC →AB + C) are examined by the quantum-mechanicalab initio methods via calculations of bond orders and energies. Results reveal that, during these reactions, a small free valence develops on the migrating atom. As a result, the degree of bond-cleavage is more advanced than that of bond-formation with a common migrating atom at the transition state. The fact that bond-formation lags behind bond-cleavage is also examined by the configuration mixing of the reactant configurations at the early stages of the reaction.

Keywords

Bond-cleavage bond-formation free valence asynchronous reaction 

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References

  1. 1.
    Agmon N and Levine R D 1977Chem. Phys. Lett. 52 197CrossRefGoogle Scholar
  2. 2.
    Evans M G and Polanyi M 1938Trans. Faraday Soc. 34 11CrossRefGoogle Scholar
  3. 3.
    Dewar M J S 1984J. Am. Chem. Soc. 106 209CrossRefGoogle Scholar
  4. 4.
    Chandra A K and Sreedhara Rao V 1996Int. J. Quantum Chem. 58 57CrossRefGoogle Scholar
  5. 5.
    Mayer I 1983Chem. Phys. Lett. 97 270; Mayer I 1985Chem. Phys. Lett. 117 396CrossRefGoogle Scholar
  6. 6.
    Pauling L 1960The nature of the chemical bond 3rd edn (Ithaca: Cornell University Press)Google Scholar
  7. 7.
    Johnston H S 1966Gas phase reaction rate theory (New York: Ronald)Google Scholar
  8. 8.
    Mayer I 1986Int. J. Quantum Chem. 29 73, 477CrossRefGoogle Scholar
  9. 9.
    Natiello M and Medrano J A 1984Chem. Phys. Lett. 105 180; Natiello M and Medrano J A 1984Chem. Phys. Lett. 110 445CrossRefGoogle Scholar
  10. 10.
    Jug K, Easold E and Gopinathan M S 1989J. Comput. Chem. 10 965CrossRefGoogle Scholar
  11. 11.
    Cioslowski J and Mixon S T 1991J. Am. Chem. Soc. 113 4142CrossRefGoogle Scholar
  12. 12.
    Sannigrahi A B 1992Adv. Quantum Chem. 23 301CrossRefGoogle Scholar
  13. 13.
    Sreedhara Rao V, Sengupta D and Chandra A K 1996J. Mol. Struct. (Theochem.) 361 151CrossRefGoogle Scholar
  14. 14.
    Chandra A K and Sreedhara Rao V 1994Chem. Phys. 187 297CrossRefGoogle Scholar
  15. 15.
    Lendvay G 1989J. Phys. Chem. 93 4422CrossRefGoogle Scholar
  16. 16.
    Lendvay G 1994J. Phys. Chem. 98 6098CrossRefGoogle Scholar
  17. 17.
    Bender C F, O’Neil S V, Pearson P K and Schaefer H F III 1972Science 176 1412CrossRefGoogle Scholar
  18. 18.
    Bender C F, Pearson P K, O’Neil S V and Schaefer H F III 1972J. Chem. Phys. 56 4626CrossRefGoogle Scholar
  19. 19.
    Schaefer H F III 1985J. Phys. Chem. 89 5336CrossRefGoogle Scholar
  20. 20.
    Seuseria G E 1991J. Chem. Phys. 95 7426CrossRefGoogle Scholar
  21. 21.
    Stark K and Werner H J 1996J. Chem. Phys. 104 6515CrossRefGoogle Scholar
  22. 22.
    Frisch A M Jet al 1992Gaussian 92 (Pittsburgh, PA; Gaussian)Google Scholar
  23. 23.
    Fox G I and Schlegel H B 1992J. Phys. Chem. 96 298CrossRefGoogle Scholar
  24. 24.
    Bu Y, Cao Z and Song X 1996Int. J. Quantum Chem. 57 95CrossRefGoogle Scholar
  25. 25.
    Moller C and Plesset M S 1934Phys. Rev. 46 618CrossRefGoogle Scholar
  26. 26.
    Chandra A K and Sreedhara Rao V 1995Chem. Phys. 200 387CrossRefGoogle Scholar
  27. 27.
    Rao V S and Chandra A K 1997Int. J. Quantum Chem. 63 1099CrossRefGoogle Scholar
  28. 28.
    Chandra A K and Rao V S 1993Int. J. Quantum Chem. 47 437CrossRefGoogle Scholar

Copyright information

© the Indian Academy of Sciences 1999

Authors and Affiliations

  • Asish K Chandra
    • 1
  1. 1.Department of Inorganic and Physical ChemistryIndian Institute of ScienceBangaloreIndia

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