Novel photoactive single-walled carbon nanotube-porphyrin polymer wraps: Efficient and long-lived intracomplex charge separation

Advanced Materials

Volumn 17, Issue 7, 2005, Pages 871-875

  Guldi, Dirk M ^a   Taieb, Hagit ^b   Rahman, G M Aminur ^b   Tagmatarchis, Nikos ^c   Prato, Maurizio ^c  

^a UNIVERSITY OF ERLANGEN NUREMBERG   (Germany)

^b UNIVERSITY OF NOTRE DAME   (United States)

^c UNIVERSITY OF TRIESTE   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

ABSORPTION; CHROMOPHORES; ELECTRONIC PROPERTIES; FLUORESCENCE; FULLERENES; GRAPHITE; NANOSTRUCTURED MATERIALS; PHOSPHORUS; POLYMERS; PORPHYRINS; REDOX REACTIONS; SEMICONDUCTOR MATERIALS; SPECTROSCOPIC ANALYSIS; TRANSMISSION ELECTRON MICROSCOPY;

CHARGE SEPARATIONS; ELECTRON DONORS; POLYMER WRAPS; SINGLE-WALLED CARBON NANOTUBES (SWNT);

CARBON NANOTUBES;

EID: 17244382819     PISSN: 09359648     EISSN: None     Source Type: Journal    
DOI: 10.1002/adma.200400641     Document Type: Article

References (46)

1. a) P. J. F. Harris, Carbon Nanotubes and Related Structures: New Materials for the Twenty-First Century, Cambridge University Press, Cambridge, UK 2001.
2. b) Carbon Nanotubes: Synthesis, Structure, Properties and Applications (Eds: M. S. Dresselhaus, G. Dresselhaus, P. Avouris), Springer, Berlin 2001.
3. c) S. Reich, C. Thomsen, J. Maultzsch, Carbon Nanotubes: Basic Concepts and Physical Properties, Wiley-VCH, Weinheim, Germany 2004.
4. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
5. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
6. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
7. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
8. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
9. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
10. For recent reviews, see: a) A. Hirsch, Angew. Chem. Int. Ed. 2002, 41, 1853. b) J. L. Bahr, J. M. Tour, J. Mater. Chem. 2002, 12, 1952. c) S. Niyogi, M. A. Hamon, H. Hu, B. Zhao, P. Bhomwik, R. Sen, M. E. Itkis, R. C. Haddon, Acc. Chem. Res. 2002, 35, 1105. d) Y.-P. Sun, K. Fu, Y. Lin, W. Huang, Acc. Chem. Res. 2002, 35, 1096. e) S. Banerjee, M. G. C. Kahn, S. S. Wong, Chem. Eur. J. 2003, 9, 1898. f) D. Tasis, N. Tagmatarchis, V. Georgakilas, M. Prato, Chem. Eur. J. 2003, 9, 4000. g) C. A. Dyke, J. M. Tour, Chem. Eur. J. 2004, 10.812.
11. a) M. Alvaro, P. Atienzar, J. L. Bourdelande, H. Garcia, Chem. Phys. Lett. 2004, 384, 119.
12. b) L. W. Qu, R. B. Martin, W. J. Huang, K. F. Fu, D. Zweifel, Y. Lin, Y.-P. Sun, C. E. Bunker, B. A. Harrutf, J. R. Gord, L. F. Allard, J. Chem. Phys. 2002, 117, 8089.
13. c) N. Nakashima, Y. Tomonari, H. Murakami, Chem. Lett. 2002, 638.
14. d) V. Georgakilas, K. Kordatos, M. Prato, D. M. Guldi, M. Holzinger, A. Hirsch, J. Am. Chem. Soc. 2002, 124, 760.
15. e) D. M. Guldi, M. Marcaccio, D. Paolucci, F. Paolucci, N. Tagmatarchis, D. Tasis, E. Vazquez, M. Prato, Angew. Chem. Int. Ed. 2003, 42, 4206.
16. f) N. Tagmatarchis, M. Prato, J. Mater. Chem. 2004, 14, 437.
17. g) D. M. Guldi, G. M. A. Rahman, N. Jux, N. Tagmatarchis, M. Prato, Angew. Chem. Int. Ed. 2004, 43, 5526.
18. V. Georgakilas, D. Voulgaris, E. Vazquez, M. Prato, D. M. Guldi, A. Kukovecz, H. Kuzmany. J. Am. Chem. Soc. 2002, 124, 14318.
19. a) A. Star, Y. Liu, K. Grant, L. Ridvan, J. F. Stoddart, D. W. Steuerman, M. R. Diehl, A. Boukai, J. R. Heath, Macromolecules 2003, 36, 553.
20. b) A. Star, J. F. Stoddart, D. Steuerman, M. Diehl, A. Boukai, E. W. Wong, X. Yang, S. W. Cheng, H. Choi, J. R. Heath, Angew. Chem. Int. Ed. 2001, 40, 1721.
21. e) J. N. Coleman, A. B. Dalton, S. Curran, A. Rubio, A. P. Davey, A. Drury, B. McCarthy, B. Lahr, P. M. Ajayan, S. Roth, R. C. Barklie, W. J. Blau, Adv. Mater. 2000, 12, 213.
22. d) M. Numata, M. Asai, K. Kaneko, T. Hasegawa, N. Fujita, Y. Kitada, K. Sakurai, S. Shinkai, Chem. Lett. 2004, 33, 232.
23. e) J. Chen, H. Y. Liu, W. A. Weimer, M. D. Halls, D. H. Waldeck, G. C. Walker, J. Am. Chem. Soc. 2002, 124, 9034.
24. f) A. Star, D. W. Steuerman, J. R. Heath, J. F. Stoddart, Angew. Chem. Int. Ed. 2002, 41, 2508.
25. The Porphyrin Handbook (Eds: K. M. Kadish, K. M. Smith, R. Guilard), Academic, New York 1999.
26. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
27. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
28. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
29. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
30. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
31. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
32. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
33. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
34. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
35. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
36. See also our work on fullerene-based systems: a) H. Imahori, Y. Sakata, Adv. Mater. 1997, 9, 537. b) M. Prato, J. Mater. Chem. 1997, 7, 1097. c) N. Martín, L. Sánchez, B. Illescas, I. Pérez, Chem. Rev. 1998, 98, 2527. d) F. Diederich, M. Gomez-Lopez, Chem. Soc. Rev. 1999, 28, 263. e) H. Imahori, Y. Sakata, Eur. J. Org. Chem. 1999, 2445. f) D. M. Guldi, Chem. Commun. 2000, 321. g) D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 2001, 34, 40. h) D. M. Guldi, Chem. Soc. Rev. 2002, 37, 22. i) D. M. Guldi, M. Prato, Acc. Chem. Res. 2000, 33, 695. j) D. M. Guldi, M. Prato, Chem. Commun. 2004, 2517. k) D. M. Guldi, F. Zerbetto, V. Georgokilas, M. Prato, Acc. Chem. Res. 2005, 38, 38.
37. a) K. H. Funken, G. Horneck, B. Milow, M. Schaefer, C. Schmitz, D. Faust, J. Ortner, M. Sattlegger, US Patent 6107480, 2000.
38. b) K.-H. Funken, J. Ortner, B. Braun-Millow, D. Faust, G. Horneck, M. Schaefer, C. Schmitz, M. Sattlegger, Eur. Patent EP 0 891977 B1, 2003.
39. E. V. Basiuk, E. V. Rybak-Akimova, V. A. Basiuk, D. Acosta-Najarro, J. M. Saniger, Nano Lett. 2002, 2, 1249.
40. Shorter reaction times (i.e., heating for 1 to 2 days) lead to stronger fluorescing samples.
41. The fact that the pre-exponential factor of the 0.8 ns component increases and likewise that of the 10 ns component diminishes with increasing progress of the reaction is also important.
42. M. Melle-Franco, M. Marcaccio, D. Paolucci, F. Paolucci, V. Georgakilas, D. M. Guldi, M. Prato, F. Zerbetto, J. Am. Chem. Soc. 2004, 126, 1646.
43. J. Rodriguez, C. Kirmaier, D. Holten, J. Am. Chem. Soc. 1989, 111, 6500.
44. D. M. Guldi, P. Neta, P. Hambright, J. Chem. Soc., Faraday Trans. 1992, 88, 2013.
45. Previous reports of porphyrins with SWNTs, but not in the context of photoinduced charge transfer, are found in a) H. Murakami, T. Nomura, N. Nakashima, Chem. Phys. Lett. 2003, 378, 481.
46. Previous reports of porphyrins with SWNTs, but not in the context of photoinduced charge transfer, are found in a) H. Murakami, T. Nomura, N. Nakashima, Chem. Phys. Lett. 2003, 378, 481. b) H. Li, B. Zhou, Y. Lin, L. Gu, W. Wang, K. A. S. Fernando, S. Kumar, L. F. Allard, Y.-P. Sun, J. Am. Chem. Soc. 2004, 126, 1014.