Evidence for the transition between concerted and stepwise heterogeneous electron transfer-bond fragmentation mechanisms

Journal of the American Chemical Society

Volumn 119, Issue 51, 1997, Pages 12595-12600

  Antonello, Sabrina ^a   Maran, Flavio ^a  

^a UNIVERSITY OF PADOVA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

BENZOIC ACID DERIVATIVE;

ARTICLE; CHEMICAL BOND; CHEMICAL REACTION KINETICS; ELECTRIC POTENTIAL; ELECTROCHEMICAL ANALYSIS; ELECTRON TRANSPORT;

EID: 0031585680     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja971649f     Document Type: Article

References (38)

1. (a) Savéant, J.-M. Adv. Phys. Org. Chem. 1990, 26, 1.
2. (b) Savéant, J.-M. Acc. Chem. Res. 1993, 26, 455.
3. (a) Saeva, F. D. In Topics in Current Chemistry; Mattay, J., Ed.; Springer-Verlag: Berlin, 1990; Vol. 156, p 59.
4. (b) Schuster, G. B. In Advances in Electron Transfer Chemistry; Mariano, P. S., Ed.; JAI Press: Greenwich, CT, 1991; Vol. 1, p 163.
5. (c) Maslak, P. In Topics in Current Chemistry; Mattay, J., Ed.; Springer-Verlag: Berlin, 1993; Vol. 168, p 1.
6. (d) Gaillard, E. R.; Whitten, D. G. Acc. Chem. Res. 1996, 29, 292.
7. Savéant, J.-M. In Advances in Electron Transfer Chemistry; Mariano, P. S., Ed.; JAI Press: Greenwich, CT, 1994; Vol. 4, p 53.
8. Antonello, S.; Musumeci, M.; Wayner, D. D. M.; Maran, F. J. Am. Chem. Soc. 1997, 119, 9541.
9. For example, see: Marcus, R. A.; Sutin, N. Biochem. Biophys. Acta 1985, 811, 265.
10. Workentin, M. S.; Maran, F.; Wayner, D. D. M. J. Am. Chem. Soc. 1995, 117, 2120.
11. Maran, F.; Wayner, D. D. M.; Workentin, M. S.; et al. Manuscript in preparation.
12. Differences may arise also because of different preexponential terms in the rate expression for ET 1 and ET 3. Although the formation of the radical anion is likely an essentially adiabatic ET process, there are reasons to believe that the concerted ET to peroxides can be nonadiabatic. 6,7 This would result in a smaller preexponential factor for ET 3 and thus, at a given potential, to a less relevant weight of the rate of ET 3 relative to that of ET 1.
13. Savéant, J.-M. J. Am. Chem. Soc. 1987, 109, 6788.
14. Severin, M. G.; Farnia, G.; Vianello, E.; Arévalo, M. C. J. Electroanal. Chem. 1988, 251, 369.
15. Andrieux, C. P.; Savéant J.-M. J. Electroanal. Chem. 1986, 205, 43.
16. Andrieux, C. P.; Robert, M.; Saeva, F. D.; Savéant J.-M. J. Am. Chem. Soc. 1994, 116, 7864.
17. (a) Nicholson, R. S.; Shain, I. Anal. Chem. 1964, 36, 706.
18. (b) Nadjo, L.; Savéant, J.-M. J. Electroanal. Chem. 1973, 48, 113.
19. (c) Bard, A. J.; Faulkner, L. R. Electrochemical Methods, Fundamentals and Applications; Wiley: New York, 1980.
20. Imbeaux, J. C.; Savéant, J.-M. J. Electroanal. Chem. 1973, 44, 169.
21. (a) Herwig, K.; Lorenz, P.; Rüchardt, C. Chem. Ber. 1975, 108, 1421.
22. (b) Filliatre, C.; Maillard, B.; Villenave, J. J. Thermochim. Acta 1980, 39, 195.
23. McMahon, K.; Arnold, D. R. Can. J. Chem. 1993, 71, 450.
24. Savéant, J.-M.; Tessier, D. J. Electroanal. Chem. 1975, 65, 57.
25. Antonello, S.; Maran, F.; et al. Work in progress.
26. 19b (a) Olmstead, W. N.; Margolin, Z.; Bordwell, F. G. J. Org. Chem. 1980, 45, 3295. (b) Maran, F.; Celadon, D.; Severin, M. G.; Vianello, E. J. Am. Chem. Soc. 1991, 113, 9320.
27. 19b (a) Olmstead, W. N.; Margolin, Z.; Bordwell, F. G. J. Org. Chem. 1980, 45, 3295. (b) Maran, F.; Celadon, D.; Severin, M. G.; Vianello, E. J. Am. Chem. Soc. 1991, 113, 9320.
28. - is liable to attack CP with formation of the corresponding acid, whose main action is to act as a proton donor.
29. For example, see: Maran, F.; Roffia, S.; Severin, M. G.; Vianello, E. Electrochim. Acta 1990, 35, 81.
30. 22c (a) Savéant J.-M.; Tessier, D. Faraday Discuss. Chem. Soc. 1982, 74, 57. (b) Severin, M. G.; Arévalo, M. C.; Maran, F.; Vianello, E. J. Phys. Chem. 1993, 97, 150. (c) Arévalo, M. C.; Rodriguez, J. L.; Severin, M. G., Vianello, E. Unpublished results.
31. 22c (a) Savéant J.-M.; Tessier, D. Faraday Discuss. Chem. Soc. 1982, 74, 57. (b) Severin, M. G.; Arévalo, M. C.; Maran, F.; Vianello, E. J. Phys. Chem. 1993, 97, 150. (c) Arévalo, M. C.; Rodriguez, J. L.; Severin, M. G., Vianello, E. Unpublished results.
32. 22c (a) Savéant J.-M.; Tessier, D. Faraday Discuss. Chem. Soc. 1982, 74, 57. (b) Severin, M. G.; Arévalo, M. C.; Maran, F.; Vianello, E. J. Phys. Chem. 1993, 97, 150. (c) Arévalo, M. C.; Rodriguez, J. L.; Severin, M. G., Vianello, E. Unpublished results.
33. 13
34. -1 range.
35. 4
36. This outcome provides an a posteriori indication that the ohmic drop correction was properly adjusted in the digital acquisition of the experimental curves. It is well-known that unproper ohmic-drop compensation leads to both a negative shift and a broadening of the voltammetric curves; in terms of the convolution output this would result in a poor overlapping of the log k(E) - E plots obtained in the same potential range at different scan rates.
37. s are the high frequency and static dielectric constants of the solvent, respectively, and r is the molecular radius: Marcus, R. A. J. Chem. Phys. 1965, 43, 679. The correlation, λ(kcal/mol) = 55.7/r(Å), is obtained using selected values from previously reported data: Kojima, H.; Bard, A. J. J. Am. Chem. Soc. 1975, 97, 6317.
38. s are the high frequency and static dielectric constants of the solvent, respectively, and r is the molecular radius: Marcus, R. A. J. Chem. Phys. 1965, 43, 679. The correlation, λ(kcal/mol) = 55.7/r(Å), is obtained using selected values from previously reported data: Kojima, H.; Bard, A. J. J. Am. Chem. Soc. 1975, 97, 6317.