Dependence of intervalence-transfer bands for mixed-valence oligo(1,1′-dihexylferrocenylene)s on the oxidation number and the number of ferrocene units from two to six

Abstract

Intervalence-transfer (IT) bands at all of the mixed-valence states of oligo(1,1′-dihexylferrocenylene)s from the dimer to the hexamer, 2–6, were determined by analysis of the absorption spectra of the oligomers oxidized quantitatively with 1,1′-dichloroferrocenium hexafluorophosphate, 1, in CH₂Cl₂–acetone. Characteristic features of the IT bands are a higher energy shift in ν_max as the oxidation number for each oligomer increases and a lower energy shift in ν_max for the monocationic forms of the oligomers as the number of ferrocene units increases. A simple analysis of the shift in ν_max of IT bands was made based on a model assuming that the mixed-valence states are a linear combination of reduced (Red) and oxidized (Ox) nuclei. It is qualitatively rationalized by taking into account the change in neighboring-site combination, especially between Red–Ox and Ox–Ox, formed by photoelectron transfer, which requires extra energy due to the strain in internuclear distance.

References

1. N. S. Hush, J. Chem. Phys., 1958, 28, 962; Trans. Faraday Soc., 1961, 57, 557; Prog. Inorg. Chem., 1967, 8, 391; Electrochim. Acta, 1968, 13, 1005; Chem. Phys., 1975, 10, 361; Coord. Chem. Rev., 1985, 64, 135.
2. C. Creutz, M. D. Newton and N. Sutin, J. Photochem. Photobiol. A: Chem., 1994, 82, 47.
3. A. R. Rezvani, C. Bensimon, B. Cromp, C. Reber, J. E. Greedan, V. V. Kondratiev and R. J. Crutchley, Inorg. Chem., 1997, 36, 3322; C. E. B. Evans, M. L. Naklicki, A. R. Rezvani, C. A. White, V. V. Kondratiev and R. J. Crutchley, J. Am. Chem. Soc., 1998, 120, 13096.
4. M. B. Robin and P. Day, Adv. Inorg. Chem. Radiochem., 1967, 10, 247.
5. D. O. Cowan, R. L. Collins and F. Kaufman, J. Phys. Chem., 1971, 75, 2025; D. O. Cowan, J. Park, M. Barber and P. Swift, J. Chem. Soc., Chem. Commun., 1971, 1444; D. O. Cowan, G. A. Candela and F. Kaufman, J. Am. Chem. Soc., 1971, 93, 3889; C. LeVenda, D. O. Cowan, C. Leitch and K. Bechgaard, J. Am. Chem. Soc., 1974, 96, 6788.
6. W. H. Morrison, Jr. and D. N. Hendrickson, Inorg. Chem., 1975, 14, 2331.
7. S. Iijima, R. Saida, I. Motoyama and H. Sano, Bull. Chem. Soc. Jpn., 1981, 54, 1375; F. Delgado-Pena, D. R. Talham and D. O. Cowan, J. Organomet. Chem., 1983, 253, C43; M. J. Cohn, T.-Y. Dong, D. N. Hendrickson, S. J. Geib and A. L. Rheingold, J. Chem. Soc., Chem. Commun., 1985, 1095; T.-Y. Dong, D. N. Hendrickson, K. Iwai, M. J. Cohn, A. L. Rheingold, H. Sano, I. Motoyama and S. Nakashima, J. Am. Chem. Soc., 1985, 107, 7996; M. F. Moore, S. R. Wilson, M. J. Cohn, T.-Y. Dong, U. T. Mueller-Westerhoff and D. N. Hendrickson, Inorg. Chem., 1985, 24, 4559; T.-Y. Dong, T. Kambara and D. N. Hendrickson, J. Am. Chem. Soc., 1986, 108, 5857; T. Kambara, D. N. Hendrickson, T.-Y. Dong and M. J. Cohn, J. Chem. Phys., 1987, 86, 2362; S. Nakashima, M. Katada, I. Motoyama and H. Sano, Bull. Chem. Soc. Jpn., 1987, 60, 2253; M. Kai, K. Katada and H. Sano, Chem. Lett., 1988, 1523; T.-Y. Dong, T. J. Ke, S. M. Peng and S. K. Yeh, Inorg. Chem., 1989, 28, 2103; T.-Y. Dong, M. Y. Hwang and Y. S. Wen, J. Organomet. Chem., 1990, 391, 377; R. J. Webb, S. J. Geib, D. L. Staley, A. L. Rheingold and D. N. Hendrickson, J. Am. Chem. Soc., 1990, 112, 5031; T.-Y. Dong, C. C. Schei, T. L. Hsu, S. L. Lee and S. J. Li, Inorg. Chem., 1991, 30, 2457; R. J. Webb, T.-Y. Dong, C. G. Pierpont, S. R. Boone, R. K. Chadha and D. N. Hendrickson, J. Am. Chem. Soc., 1991, 113, 4806; R. J. Webb, P. M. Hagen, R. J. Wittebort, M. Sorai and D. N. Hendrickson, Inorg. Chem., 1992, 31, 1791; T.-Y. Dong, T. Y. Lee and H. M. Lin, J. Organomet. Chem., 1992, 427, 101; T.-Y. Dong, C. K. Chang, C. H. Huang, Y. S. Wen, S. L. Lee, J. A. Chen, W. Y. Yeh and A. Yeh, J. Chem. Soc., Chem. Commun., 1992, 526; T.-Y. Dong, C. H. Huang, C. K. Chang, Y. S. Wen, S. L. Lee, J. A. Chen, W. Y. Yeh and A. Yeh, J. Am. Chem. Soc., 1993, 115, 6357; T.-Y. Dong and C. C. Schei, J. Organomet. Chem., 1993, 447, 107.
8. T.-Y. Dong, T.-Y. Lee, S.-H. Lee, G.-H. Lee and S.-M. Peng, Organometallics, 1994, 13, 2337; T.-Y. Dong, S.-H. Lee, C.-K. Chang and K.-J. Lin, J. Chem. Soc., Chem. Commun., 1995, 2453.
9. T.-Y. Dong, C.-H. Huang, C.-K. Chang, H.-C. Hsieh, S.-M. Peng and G.-H. Lee, Organometallics, 1995, 14, 1776.
10. K. Boukheddaden, J. Linares, A. Bousseksou, J. Nasser, H. Rabah and F. Varret, Chem. Phys., 1993, 170, 47.
11. G. M. Brown, T. J. Meyer, D. O. Cowan, C. LeVanda, F. Kaufman, P. V. Roling and M. D. Rausch, Inorg. Chem., 1975, 14, 506.
12. U. T. Mueller-Westerhoff and P. Eilbracht, J. Am. Chem. Soc., 1972, 94, 9271; C. U. Pittman, Jr. and B. Surynarayanan, J. Am. Chem. Soc., 1974, 96, 7916; C. Levanda, K. Bechgaard, D. O. Cowan, U. T. Mueller-Westerhoff, P. Elbracht, G. A. Candela and R. L. Collins, J. Am. Chem. Soc., 1976, 98, 3181.
13. H. Nishihara, M. Ohta and K. Aramaki, J. Chem. Soc., Faraday Trans., 1992, 827; K. Sakamoto, H. Nishihara and K. Aramaki, J. Chem. Soc., Dalton Trans., 1992, 1877; H. Nishihara, T. Nakagawa and K. Aramaki, Electroanalysis, 1996, 8, 831.
14. M. Rosenblum, N. Brown, J. Papenmier and M. Applebaum, J. Organomet. Chem., 1966, 6, 173; M. Rosenblum, N. M. Brawn, D. Ciappenelli and J. Tancrede, J. Organomet. Chem., 1970, 24, 469; C. Lavenda, K. Bechgaard and D. O. Cowan, J. Org. Chem., 1976, 41, 2700; J. A. Kramer and D. N. Hendrickson, Inorg. Chem., 1980, 19, 3330; R. L. Blackbourn and J. T. Hupp, J. Phys. Chem., 1990, 94, 1788.
15. H. Atzkern, P. Bergerat, M. Fritz, J. Hiermeier, P. Hudeczek, O. Kahn, B. Kanellakopulos, F. H. Köhler and M. Ruhs, Chem. Ber., 1994, 127, 277; H. Atzkern, P. Bergerat, H. Beruda, M. Fritz, J. Hiermeier, P. Hudeczek, O. Kahn, F. H. Köhler, M. Paul and B. Weber, J. Am. Chem. Soc., 1995, 117, 997.
16. A.-C. Riboou, J.-P. Launay, M. L. Sachtleben, H. Li and C. W. Spangler, Inorg. Chem., 1996, 35, 3735.
17. S. I. Amer, G. Sadler, P. M. Henry, G. Ferguson and B. L. Ruhl, Inorg. Chem., 1985, 24, 1517.
18. S. Barlow, V. J. Murphy, J. S. O. Evans and D. O'Hare, Organometallics, 1995, 14, 3461.
19. R. Rulkens, A. J. Lough, I. Manners, S. R. Lovelace, C. Grant and W. E. Geiger, J. Am. Chem. Soc., 1996, 118, 12683.
20. T. Hirao, M. Kurashina, K. Aramaki and H. Nishihara, J. Chem. Soc., Dalton Trans., 1996, 2929.
21. H. Nishihara, T. Hirao, K. Aramaki and K. Aoki, Synth. Metals, 1997, 84, 935.
22. K. Aoki and J. Chen, J. Electroanal. Chem. Interfacial Electrochem., 1995, 380, 35.
23. K. Aoki, J. Chen, H. Nishihara and T. Hirao, J. Electroanal. Chem. Interfacial Electrochem., 1996, 416, 151.
24. T. Horikoshi and H. Nishihara, Synth. Metals, 1999, 102, 1523.
25. D. W. Slocum, T. R. Engelmann, C. Ernst, C. A. Jennings, W. Jones, B. Koonsvitsky, J. Lews and P. Shenkin, J. Chem. Educ., 1969, 46, 144.
26. D. N. Hendrickson, Y. S. Sohn and H. B. Gray, Inorg. Chem., 1971, 10, 1559; D. M. Duggan and D. N. Hendrickson, Inorg, Chem., 1975, 14, 955.
27. T. Hirao, K. Aramaki and H. Nishihara, Bull. Chem. Soc. Jpn., 1998, 71, 1817.