The first electrochemical study of a silene. An unusually low oxidation potential, comparable to those of strong organic π-electron donors

Organometallics

Volumn 23, Issue 4, 2004, Pages 921-923

  Bendikov, Michael ^a   Kravchenko, Victoria ^a   Apeloig, Yitzhak ^a   Becker, James Y ^b  

^a TECHNION ISRAEL INSTITUTE OF TECHNOLOGY   (Israel)

^b BEN GURION UNIVERSITY OF THE NEGEV   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLIC VOLTAMMETRY; DECOMPOSITION; ELECTROCHEMISTRY; ELECTRONIC STRUCTURE; ELECTRONS; OXIDATION; PHYSICAL PROPERTIES;

ELECTRON DONORS; LOW OXIDATION POTENTIAL; SILENE;

SILICON COMPOUNDS;

EID: 1442285088     PISSN: 02767333     EISSN: None     Source Type: Journal    
DOI: 10.1021/om0341909     Document Type: Article

References (39)

1. Gusel'nikov, L. E.; Flowers, M. C. Chem. Commun. 1967, 864.
2. For the most recent comprehensive review on silenes see: Müller, T.; Ziche, W.; Auner, N. In The Chemistry of Organic Silicon Compounds; Rappoport, Z., Apeloig, Y., Eds.; Wiley: Chichester, U.K., 1998; Vol. 2, Chapter 16.
3. For previous reviews see: (a) Raabe, G.; Michl, J. In The Chemistry of Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester, U.K., 1989; Chapter 17.
4. (b) Brook, A. G.; Brook, M. A. Adv. Organomet. Chem. 1996, 39, 71.
5. (c) Raabe, G.; Michl, J. Chem. Rev. 1985, 85, 419.
6. (a) Buffy, J. J.; West, R.; Bendikov, M.; Apeloig, Y. J. Am. Chem. Soc. 2001, 123, 978.
7. (b) Bendikov, M.; Solouki, B.; Auner, N.; Apeloig, Y. Organometallics 2002, 21, 1349.
8. (c) Bendikov, M.; Apeloig, Y.; Bukalov, S.; Garbuzova, I.; Leites, L. J. Phys. Chem. A 2002, 106, 4880.
9. Apeloig, Y.; Bendikov, M.; Yuzefovich, M.; Nakash, M.; Bravo-Zhivotovskii, D.; Bläser, D.; Boese, R. J. Am. Chem. Soc. 1996, 118, 12228.
10. +/Fc as external standard (diffusion controlled) indicates that the electron-transfer process involves one electron.
11. 2, it is probable that only a fraction of silene 1 survives during the measurements.
12. (a) We disregard cases in which the organosilicon compound is oxidized or reduced not at the silicon atom but at different atoms.
13. (b) Reversible chemical oxidation and reduction of cyclotetrasilenyl radical were reported recently; Matsuno, T.; Ichinohe, M.; Sekiguchi, A. Angew. Chem., Int. Ed. 2002, 41, 1575.
14. A two-electron redox process leading to a dication or dianion is highly unlikely (HOMO-1 and LUMO+1 separated from FMO by at least 1.4 eV, at MP2/6-31G*//B3LYP/6-31G* and B3LYP/6-31G*//B3LYP/6-31G*).
15. Fuchigami, T. In The Chemistry of Organosilicon Compounds; Rappoport, Z., Apeloig, Y., Eds.; Wiley: Chichester, U.K., 1998; Vol. 2, Chapter 23.
16. 3) = -0.07: Hansch, C.; Leo, A.; Taft, R. W. Chem. Rev. 1991, 91, 165.
17. 2: Moore, A. J.; Bryce, M. R.; Ando, D. A.; Hursthouse, M. B. J. Chem. Soc., Chem. Commun. 1991, 320.
18. Bryce, M. R.; Marshallsay, G. J.; Moore, A. J. J. Org. Chem. 1992, 57, 4859.
19. The oxidation and reduction potentials were measured in different solvents. This may change the gap by 0.1-0.2 V.
20. This kind of comparison has to be made with great care and reservation because the oxidation of ethylene and tetramethylethylene is irreversible, whereas that for 1 is reversible.
21. Encyclopedia of Electrochemistry of the Elements; Bard, A. J., Ed.; Marcel Dekker: New York, 1978; Vol. XI, Chapter 1.
22. Gersdorf, J.; Mattay, J.; Goerner, H. J. Am. Chem. Soc. 1987, 109, 1203.
23. 2 in DMF are reduced at -2.4, -2.25, and ∼-2 V, respectively (Ag/AgCl corrected); see: Technique of Electro-organic Synthesis. In Techniques of Chemistry; Weisberger, A., Ed.; Wiley: New York, 1975; Vol. V, (Weinberg, N., Vol. Ed.), Part II, pp 679-685.
24. Burkholder, C.; Dolbier, W. R., Jr.; Médebielle, M. J. Org. Chem. 1998, 6 3, 5385.
25. Shepherd, B. D.; West, R. Chem. Lett. 1988, 2, 183.
26. Kira, M.; Ishima, T.; Iwamoto, T.; Ichinohe, M. J. Am. Chem. Soc. 2001, 123, 1676.
27. 2 was electrolyzed preparatively: Zhang, Z.-R.; Becker, J. Y.; West, R. Chem. Commun. 1998, 2719.
28. All reductions and oxidations of disilenes were found to be irreversible. Therefore, see footnote 14.
29. -1. Schleyer, P. v. R.; Kost, D. J. Am. Chem. Soc. 1988, 110, 2105.
30. Lias, S. G. In Ionization Energy Evaluation; Mallard, W. G., Linstrom, P. J., Eds.; NIST Chemistry WebBook, NIST Standard Reference Database Number 69, July 2001; National Institute of Standards and Technology: Gaithersburg, MD 20899 (http://webbook.nist.gov).
31. All calculations used the GAUSSIAN 98 series of programs: Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A., Jr.; Stratmann, R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Rega, N.; Salvador, P.; Dannenberg, J. J.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Baboul, A. G.; Stefanov, B. B.; Liu, G. Liashenko, A. Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Andres, J. L.; Gonzalez, C.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian 98, Revision A.11.4; Gaussian, Inc., Pittsburgh, PA, 2002.
32. Okazaki, R.; West, R. Adv. Organomet. Chem. 1996, 39, 231.
33. For a detailed discussion of substituent effects on the HOMO energy of silene 1, see ref 4b.
34. Wenthold, P. G. Chem. Phys. Lett. 1998, 297, 445.
35. Pak, C.; Rienstra-Kiracofe, J. C.; Schaefer, H. F., III. J. Phys. Chem. A 2000, 104, 11232.
36. 19
37. Roncali, J. Chem. Rev. 1997, 97, 173.
38. The reorganization energy is the energy released on relaxation of a cation radical in an adiabatic transition.
39. Eberson, L. Electron-Transfer Reactions in Organic Chemistry; Springer-Verlag: Berlin, 1987.