Direct measurement of ultrafast carbon-carbon cleavage rates via the subpicosecond charge-transfer activation of pinacols

Journal of the American Chemical Society

Volumn 120, Issue 26, 1998, Pages 6542-6547

  Bockman, T M ^a   Hubig, S M ^a   Kochi, J K ^a  

^a University of Houston   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALKANEDIOL DERIVATIVE;

ARTICLE; CHEMICAL REACTION KINETICS; ELECTRON TRANSPORT; IN VITRO STUDY; PHOTOACTIVATION; PHOTOCHEMISTRY; SPECTROPHOTOMETRY;

EID: 0032496955     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja980097d     Document Type: Article

References (52)

1. (a) Penn, J, H.; Duncan, J. H. J. Org. Chem. 1993, 58, 2003.
2. (b) Han, D. S.; Shine, H. J. J. Org. Chem. 1996, 61, 3977.
3. (c) Lopez, L.; Mele, G.; Mazzeo, C. J. Chem. Soc., Perkin Trans, 1 1994, 779.
4. For a general review of oxidative cleavages of pinacols, see: House, H. O. Modern Synthetic Reactions, 2nd ed.; Benjamin: New York, 1972; p 353f.
5. (a) Reichel, L. W.; Griffin, G. W.; Muller, A. J.; Das, P. K.; Ege, S. N. Can. J. Chem. 1984, 62, 424.
6. (b) Davis, H. F.; Das, P. K.; Reichel, L. W.; Griffin, G. W. J. Am. Chem. Soc. 1984, 106, 6968.
7. (c) Chen, L.; Farahat, M. S.; Gaillard, E. R.; Farid, S.; Whitten, D. G. J. Photochem. Photobiol. A 1996, 95, 21.
8. (d) Perrier, S.; Sankararaman, S.; Kochi, J. K. J. Chem. Soc., Perkin Trans. 2 1993, 825.
9. (e) Sankararaman, S.; Kochi, J. K. J. Chem. Soc., Chem. Commun. 1989, 1800.
10. (f) Albini, A.; Spreti, S. J. Chem. Soc., Perkin Trans. 2 1987, 1175.
11. (a) Maslak, P. Top. Curr. Chem. 1993, 168, 1.
12. (b) Maslak, P.; Chapman, W. H., Jr. J. Org. Chem. 1996, 61, 2647.
13. (c) Wayner, D. D. M.; Parker, V. D. Acc. Chem. Res. 1993, 26, 287.
14. (a) Hubig, S. M.; Bockman, T. M.; Kochi, J. K. J. Am. Chem. Soc. 1996, 118, 3842.
15. (b) Bockman, T. M.; Hubig, S. M.; Kochi, J. K. J. Org. Chem. 1997, 62, 2210.
16. (c) Bockman, T. M.; Hubig, S. M.; Kochi, J. K. J. Am. Chem. Soc. 1996, 118, 4502.
17. Charge-transfer excitation of electron donor-acceptor complexes effects the transfer of an electron from the donor to the acceptor in less than 500 fs to produce the donor cation radical in the ground state. See: Wynne, K.; Galli, C.; Hochstrasser, R. M. J. Chem. Phys. 1994, 100, 4797. Thus the CT excited state (as the precursor to the ion-radical pair) must have a very short lifetime, and it is not chemically significant on the picosecond time scale.
18. (a) Watanabe, T.; Honda, K. J. Phys. Chem. 1982, 86, 2617.
19. (b) Bookman, T. M.; Kochi, J. K. J. Org. Chem. 1990, 55, 4127.
20. +• are essentially the same as those of the cation radicals of the methylbiphenyls, which were generated independently by CT excitation of their EDA complex with tetracyanobenzene. Compare: Ojima, S.; Miyasaka, H.; Mataga, N. J. Phys. Chem. 1990, 94, 7534.
21. 8
22. Dimethyl dicyanofumarate has been identified as a versatile electron acceptor in thermal electron-transfer reactions. See: Gotoh, T.; Padias, A. B.; Hall, H. K., Jr. J. Am. Chem. Soc. 1986, 108, 4920.
23. The cation radicals of the methoxy-substimted pinacols absorb in the same wavelength region (450-470 nm) as the anisole cation radical. See: Takamaku, S.; Komitsu, S.; Toki, S. Radiat. Phys. Chem. 1989, 34, 553.
24. See: (a) Asahi, T.; Mataga, N. J. Phys. Chem. 1989, 93, 6575. (b) Asahi, T.; Mataga, N. J. Phys. Chem. 1991, 95, 1956. (c) Peters, K. S. Adv. Electron-Transfer Chem. 1994, 4, 27. (d) Hilinski, E. F.; Masnovi, J. M.; Kochi, J. K.; Rentzepis, P. M. J. Am. Chem. Soc., 1984, 106, 8071. (e) Fox, M. A. Adv. Photochem. 1986, 13, 237.
25. See: (a) Asahi, T.; Mataga, N. J. Phys. Chem. 1989, 93, 6575. (b) Asahi, T.; Mataga, N. J. Phys. Chem. 1991, 95, 1956. (c) Peters, K. S. Adv. Electron-Transfer Chem. 1994, 4, 27. (d) Hilinski, E. F.; Masnovi, J. M.; Kochi, J. K.; Rentzepis, P. M. J. Am. Chem. Soc., 1984, 106, 8071. (e) Fox, M. A. Adv. Photochem. 1986, 13, 237.
26. See: (a) Asahi, T.; Mataga, N. J. Phys. Chem. 1989, 93, 6575. (b) Asahi, T.; Mataga, N. J. Phys. Chem. 1991, 95, 1956. (c) Peters, K. S. Adv. Electron-Transfer Chem. 1994, 4, 27. (d) Hilinski, E. F.; Masnovi, J. M.; Kochi, J. K.; Rentzepis, P. M. J. Am. Chem. Soc., 1984, 106, 8071. (e) Fox, M. A. Adv. Photochem. 1986, 13, 237.
27. See: (a) Asahi, T.; Mataga, N. J. Phys. Chem. 1989, 93, 6575. (b) Asahi, T.; Mataga, N. J. Phys. Chem. 1991, 95, 1956. (c) Peters, K. S. Adv. Electron-Transfer Chem. 1994, 4, 27. (d) Hilinski, E. F.; Masnovi, J. M.; Kochi, J. K.; Rentzepis, P. M. J. Am. Chem. Soc., 1984, 106, 8071. (e) Fox, M. A. Adv. Photochem. 1986, 13, 237.
28. See: (a) Asahi, T.; Mataga, N. J. Phys. Chem. 1989, 93, 6575. (b) Asahi, T.; Mataga, N. J. Phys. Chem. 1991, 95, 1956. (c) Peters, K. S. Adv. Electron-Transfer Chem. 1994, 4, 27. (d) Hilinski, E. F.; Masnovi, J. M.; Kochi, J. K.; Rentzepis, P. M. J. Am. Chem. Soc., 1984, 106, 8071. (e) Fox, M. A. Adv. Photochem. 1986, 13, 237.
29. For examples, see: Bockman et al. in ref 5b and Masnovi et al. (Masnovi, J. M.; Kochi, J. K.; Hilinski, E. F.; Rentzepis, P. M. J. Am. Chem. Soc. 1986, 108, 1126). See also Ojima et al. in ref 8.
30. See: Hayon, E.; Ibata, T.; Lichtin, N. N.; Simic, M. J. Phys. Chem. 1972, 76, 2072, and ref 5b.
31. Ojima, S.; Miyasaka, H.; Mataga, N. J. Phys. Chem. 1990, 94, 4147.
32. Itoh, M.; Nagakura, S. Bull. Chem. Soc. Jpn. 1966, 39, 369.
33. .14 For the extinction coefficient of the reduced methyl viologen, see ref 9. (b) Ireland, J. F; Wyatt, P. A. H. J. Chem. Soc., Faraday Trans. 1 1973, 69, 161.
34. Asahi, T.; Ohkohchi, M.; Mataga, N. J. Phys. Chem. 1993, 97, 13132.
35. Estimated on the basis of the Eyring equation. See: Moore, J. W.; Pearson, R. G. Kinetics and Mechanism, 3rd ed.; Wiley: New York, 1981; p 173.
36. -1). See: Birkhofer, H.; Beckhaus, H.-D.; Peters, K.; von Schnering, H.-G.; Rüchardt, C. Chem. Ber. 1993, 126, 1693.
37. 2+ to complete the stoichiometry for the retropinacol reaction occurs by second-order kinetics and is too slow to be observed on the picosecond time scale.
38. -2). See, e.g.: Jones, G., II In Photoinduced Electron Transfer: Part A; Fox, M. A., Chanon, M., Eds.; Elsevier: Amsterdam, 1988; p 245.
39. See, e.g.: (a) Kavarnos, G. J.; Turro, N. J. Chem. Rev. 1986, 86, 401. (b) Gould, I. R.; Farid, S. Acc. Chem. Res. 1996, 29, 522. (c) Mauzerall, D. C. In Photoinduced Electron Transfer: Part A; Fox, M. A., Chanon, M., Eds.; Elsevier: Amsterdam, 1988; p 228.
40. See, e.g.: (a) Kavarnos, G. J.; Turro, N. J. Chem. Rev. 1986, 86, 401. (b) Gould, I. R.; Farid, S. Acc. Chem. Res. 1996, 29, 522. (c) Mauzerall, D. C. In Photoinduced Electron Transfer: Part A; Fox, M. A., Chanon, M., Eds.; Elsevier: Amsterdam, 1988; p 228.
41. See, e.g.: (a) Kavarnos, G. J.; Turro, N. J. Chem. Rev. 1986, 86, 401. (b) Gould, I. R.; Farid, S. Acc. Chem. Res. 1996, 29, 522. (c) Mauzerall, D. C. In Photoinduced Electron Transfer: Part A; Fox, M. A., Chanon, M., Eds.; Elsevier: Amsterdam, 1988; p 228.
42. -1 is consistent with simple diffusive separation of the ions in contact ion pairs. See: (b) Knibble, H.; Rehm, D.; Weller, A. Ber. Bunsen-Ges. Phys. Chem. 1968, 72, 257.
43. (c) Ojima, S.; Miyasaka, H.; Mataga, N. J. Phys. Chem. 1990, 94, 7534. For the separation of cation-cation pairs, see:
44. (d) Hubig, S. M. J. Phys. Chem. 1992, 96, 2903.
45. -•].
46. Ireland, C. J.; Jones, K.; Pizey, J. S.; Johnson, S. Synthet. Commun. 1976, 6, 185.
47. Sisido, K.; Nozaki, H. J. Am. Chem. Soc. 1948, 70, 778.
48. Depovere, P.; Devis, R. Bull. Soc. Chim. Fr. 1968, 6, 2470.
49. Bachmann, W. E. In Organic Syntheses; Blatt, A. H., Ed.; Wiley: New York, 1943; Collect. Vol. II, p 71.
50. Perrier, S. Ph.D. Thesis, University of Houston, 1995.
51. 31b were used. (b) Bookman, T. M.; Kochi, J. K. J. Chem. Soc., Perkin Trans. 2 1996, 1633.
52. Peters, K. S.; Li, B. J. Phys. Chem. 1994, 98, 401.