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Inter-ring η6⇌η5 haptotropic rearrangements of 18ē and 19ē (η5-pentamethylcyclopentadienyl)(η6-9-methylfluorenyl)iron complexes

Abstract

New cationic complexes [(η6-C13H10)Fe(η5-Cp*)]PF6 and [(η6-9-CH3-C13H9)Fe(η5-Cp*)]PF6 were obtained by the reaction of Cp*Fe(CO)2Br with fluorene and 9-methylfluorene, respectively. Deprotonation of these complexes byt-BuOK in THF affords zwitter-ionic compounds (η6-C13H9)Fe(η5-Cp*) and (η6-9-CH3-C13H8)Fe(η5-Cp*) (A). WhenA is heated in nonane at 150 °C it undergoes η6⇌η5 inter-ring rearrangement with the formation of hexamethyldibenzoferrocene (B). The electrochemical behavior ofA andB was studied by cyclic voltammetry. One-electron reduction ofA andB to the corresponding radical anions induces inter-ring haptotropic rearrangementA .−⇌ηB .−. The equilibrium in the 19ē state is shifted to the η6-isomeric radical anionA .−, while in the 18ē precursors, it shifts to the η5-isomerB.

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References

  1. 1.

    T. A. Albright, P. Hoffmann, R. Hoffmann, O. P. Lillya, and P. A. Dobosh,J. Am. Chem. Soc., 1983,105, 3396.

  2. 2.

    N. A. Ustynyuk,Metalloorg. Khim., 1989,2, 43 [J. Organomet. Chem. USSR, 1989,2 (Engl. Transl.)].

  3. 3.

    Yu. F. Oprunenko, S. G. Malyugina, O. I. Trifonova, O. Ya. Babushkina, A. P. Pisarevskii, Yu. A. Ustynyuk, N. A. Ustynyuk, D. N. Kravtsov, and P. N. Nesterenko,Izv. Akad. Nauk SSSR, Ser. Khim., 1988, 438 [Bull. Acad. Sci. USSR, Div. Chem. Sci., 1988,37, 357 (Engl. Transl.)]; E. P. Kundig, V. Desobry, C. Grivet, B. Rudolph, and S. Spichiger,Organometallics, 1987,6, 1173; R. U. Kirss and P. M. Treichel,J. Am. Chem. Soc., 1986,108, 853; Yu. F. Oprunenko, S. G. Malyugina, O. Ya. Babushkina, Yu. A. Ustynyuk, P. N. Nesterenko, N. A. Ustynyuk, D. N. Kravtsov, and V. A. Piven',Metalloorg. Khim., 1988,1, 384 [J. Organomet. Chem. USSR, 1988,1 (Engl. Transl.)]; Yu. F. Oprunenko, I. A. Shaposhnikova, Yu. A. Ustynyuk, N. A. Ustynyuk, and D. N. Kravtsov,Izv. Akad. Nauk SSSR, Ser. Khim., 1987, 703 [Bull. Acad. Sci. USSR, Div. Chem. Sci., 1987,36, 644 (Engl. Transl.)]; T. G. Traylor and K. J. Stewart,J. Am. Chem. Soc., 1986,108, 6977.

  4. 4.

    N. A. Ustynyuk, B. V. Lokshin, Yu. F. Oprunenko, V. A. Roznyatovsky, Yu. N. Luzikov, and Yu. A. Ustynyuk,J. Organomet. Chem., 1980,202, 279; M. E. Rerek and F. Basolo,Organometallics, 1984,3, 647; P. M. Treichel and J. W. Johnson,Inorg. Chem., 1977,16, 749; N. A. Ustynyuk, L. N. Novikova, V. K. Belski, Yu. F. Oprunenko, S. G. Malyugina, O. I. Trifonova, and Yu. A. Ustynyuk,J. Organomet. Chem., 1985,294, 31.

  5. 5.

    S. V. Kukharenko, V. V. Strelets, N. A. Ustynyuk, L. N. Novikova, L. I. Denisovich, and M. G. Peterleitner,Metalloorg. Khim., 1991,4, 299 [J. Organomet. Chem. USSR, 1991,4 (Engl. Transl.)].

  6. 6.

    J.-R. Hamon and D. Astruc,J. Am. Chem. Soc., 1981,103, 758.

  7. 7.

    N. A. Pomazanova, I. N. Novikova, N. F. Ustynyuk, and D. N. Kravtsov,Izv. Akad. Nauk SSSR, Ser. Khim., 1986, 1688 [Bull. Acad. Sci. USSR, Div. Chem. Sci., 1986,35, 1538 (Engl. Transl.)].

  8. 8.

    R. B. King and M. B. Bisnette,J. Organomet. Chem., 1967,8, 287.

  9. 9.

    S. V. Kukharenko, G. L. Soloveichik, and V. V. Strelets,Izv. Akad. Nauk SSSR, Ser. Khim., 1986, 1020 [Bull. Acad. Sci. USSR, Div. Chem. Sci., 1986,35, 926 (Engl. Transl.)].

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Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 319–324, February, 1994.

The authors are grateful to D. V. Zagorevskii (A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences) for recording and interpreting the mass spectra, and to A. A. Borisenko (Moscow State University) for recording the NMR spectra.

This work was financially supported by the Russian Foundation for Basic Research (Grant 93-03-5209).

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Novikova, L.N., Mazurchik, B.A., Ustynyuk, N.A. et al. Inter-ring η6⇌η5 haptotropic rearrangements of 18ē and 19ē (η5-pentamethylcyclopentadienyl)(η6-9-methylfluorenyl)iron complexes. Russ Chem Bull 43, 299–303 (1994). https://doi.org/10.1007/BF00695835

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Key words

  • iron
  • π-complexes
  • haptotropic rearrangements
  • electron transfer-induced reaction
  • cyclic voltammetry