Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
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The Effect of Medium on the α -Effect: Nucleophilic Substitution Reaction of p-Nitrothenyl Diphenyl Phosphinate with Butane-2,3-dione Monoximate and Substituted Phenoxides in Cationic Micelles

  • Published : 2002.09.20
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Abstract

Pseudo-first-order rate constants (kobs) have been determined for the nucleophilic substitution reactions of p-nitrophenyl diphenyl phosphinate (PNPDPP) with substituted phenoxides (XC6H4O - ) and butane-2,3-dione monoximate (Ox- ) in 0.1 M borate buffer (pH = 10.0) at 25.0 ${\pm}0.1^{\circ}C$. The kobs value increases sharply upon addition of cethyltrimethylammonium bromide (CTAB) to the reaction medium up to near 7 ${\times}$ 10-4 M CTAB and then decreases smoothly upon further addition of CTAB. The rate enhancement upon the addition of CTAB is most significant for the reaction with -O2CC6H4O- and least significant for the one with C6H5O- , indicating that the reactivity of these aryloxides in the presence of CTAB cannot be determined by the basicity alone. The strength of the interaction of these anionic aryloxides with the positively charged micellar aggregates has been suggested to be an important factor to determine the reactivity in the presence of CTAB. The kobs value for the reaction with Ox- increases also upon the addition of CTAB. However, the increase in the kobs value is much more significant for the reaction with Ox- than for the one with ClC6H4O- , indicating that Ox- is less strongly solvated than ClC6H4O- in H2O. The ${\alpha}-effect$ shown by Ox- in H2O has been attributed to the ground-state solvation difference between Ox- and ClC6H4O- .

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References

  1. Edwards, J. O.; Pearson, R. G. J. Am. Chem. Soc. 1962, 84, 16. https://doi.org/10.1021/ja00860a005
  2. Buncel, E.; Hoz, S. Isr. J. Chem. 1985, 26, 313. https://doi.org/10.1002/ijch.198500113
  3. Fina, N. J.; Edward, J. O. Int. J. Chem. Kinet. 1973, 5, 1. https://doi.org/10.1002/kin.550050102
  4. Grekov, A. P.; Veselov, V. Y. Usp. Khim. 1978, 47, 1200.
  5. Moutiers, G.; Guevel, E. L.; Vilien, L.; Terrier, F. J. Chem. Soc. Perkin Trans. 2 1997, 7.
  6. Terrier, F.; Moutiers, G.; Xiao, L.; Guir, F. J. Org. Chem. 1995, 60, 1748. https://doi.org/10.1021/jo00111a037
  7. Fountain, K. R.; Tad-y, D. B.; Paul, T. W.; Golynskiy, M. V. J. Org. Chem. 1999, 64, 6547. https://doi.org/10.1021/jo981902+
  8. Fountain, K. R.; Dunkin, T. W.; Patel, K. D. J. Org. Chem. 1997, 62, 3711. https://doi.org/10.1021/jo9618233
  9. Fountain, K. R.; Patel, K. D. J. Org. Chem. 1997, 62, 4795. https://doi.org/10.1021/jo9606012
  10. Herschlag, D.; Jencks, W. P. J. Am. Chem. Soc. 1990, 112, 1951. https://doi.org/10.1021/ja00161a047
  11. Herschlag, D.; Jencks, W. P. J. Am. Chem. Soc. 1989, 111, 7579. https://doi.org/10.1021/ja00201a047
  12. Palling, D. J.; Jencks, W. P. J. Am. Chem. Soc. 1984, 106, 4869. https://doi.org/10.1021/ja00329a040
  13. Bernasconi, C. F.; Murray, C. J. J. Am. Chem. Soc. 1986, 108, 5251. https://doi.org/10.1021/ja00277a032
  14. Dixon, J. E.; Bruice, T. C. J. Am. Chem. Soc. 1972, 94, 2052. https://doi.org/10.1021/ja00761a043
  15. Buncel, E.; Um, I. H. J. Chem. Soc. Chem. Commun. 1986, 595.
  16. Um, I. H.; Buncel, E. J. Org. Chem. 2000, 65, 577. https://doi.org/10.1021/jo9915776
  17. Um, I. H.; Lee, E. J.; Buncel, E. J. Org. Chem. 2001, 66, 4859. https://doi.org/10.1021/jo0156114
  18. Um, I. H.; Park, Y. M.; Buncel, E. Chem. Commun. 2000, 1917.
  19. Um, I. H. Bull. Korean Chem. Soc. 1990, 11, 173.
  20. Fendler, J. H.; Fendler, E. J. Catalysis in Micellar and Macromolecular Sustems; Academic Press: New York, 1975.
  21. Iglasias, E. J. Phys. Chem. B 2001, 105, 10287. https://doi.org/10.1021/jp010074c
  22. Toullec, J.; Moukawim, M. Chem. Commun. 1996, 221.
  23. Moss, R. A.; Kotchevar, A. T.; Park, B. D.; Scrimin, P. Langmuir 1996, 12, 2200. https://doi.org/10.1021/la951093e
  24. Um, I. H.; Lee, S. E.; Jung, J. K.; Park. J. Y. Bull. Korean Chem. Soc. 1992, 13, 486.
  25. Bunton, C. A.; Sepulveda, L. J. Phys. Chem. 1979, 83, 680. https://doi.org/10.1021/j100469a008
  26. Um, I. H.; Buncel, E. J. Am. Chem. Soc. 2001, 123, 11111. https://doi.org/10.1021/ja016917v
  27. Um, I. H.; Hong, J. Y.; Buncel, E. Chem. Commun. 2001, 27.