Skip to main content
Log in

Study on excited states of hexamethoxybenzene-NO+ charge-transfer complex: incorporation of excited radical cation

  • Published:
Research on Chemical Intermediates Aims and scope Submit manuscript

Abstract

A charge-transfer (CT) complex of NOBF4 and hexamethoxybenzene (HMB), which gives out HMB•+ as a “fluorescent radical cation probe,” upon one-electron oxidation, has been designed to explore the excited state dynamics of contact radical ion pairs by laser-induced fluorescence and femtosecond transient absorption spectroscopic techniques. The acetonitrile solution of the CT complex showed weak fluorescence with a similar spectrum to that observed for free excited HMB radical cation (HMB•+*), suggesting the formation of HMB•+* upon the one-photonic excitation of the CT complex. The laser-power dependence of the fluorescence intensity supported the one-photonic excitation event. We have also observed a short-lived transient species but no long-lived species by femtosecond laser flash photolysis of the CT complex. The lifetime (6.5 ps) was in good accordance with its fluorescence quantum yield (2.5 × 10−5) and was able to assign the transient species to the fluorescent state, an excited radical ion pair [HMB+*/NO]. All the events were completed within the inner sphere and the short lifetime of the transient species could be attributed to rapid back-electron transfer. It is concluded that the excited radical cation character in the excited state of the CT complex originates from the radical ion character in the CT complex in the ground state and that a relatively long lifetime of HMB•+* facilitates its observation even in the contact ion pair.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Scheme 1
Scheme 2
Scheme 3
Fig. 1
Scheme 4
Fig. 2
Fig. 3
Fig. 4
Scheme 5
Scheme 6

Similar content being viewed by others

References

  1. G.J. Karvanos, Fundamentals of Photoinduced Electron Transfer (Wiley-VCH, New York, 1993)

    Google Scholar 

  2. I.R. Gould, S. Farid, Acc. Chem. Res. 29, 522 (1996)

    Article  CAS  Google Scholar 

  3. K. Mizuno, N. Ichinose, Y. Otsuji, J. Org. Chem. 57, 1855 (1992)

    Article  CAS  Google Scholar 

  4. H. Masuhara, N. Tsujino, N. Mataga, Bull. Chem. Soc. Jpn. 46, 1088 (1973)

    Article  CAS  Google Scholar 

  5. H. Miyasaka, S. Ojima, N. Mataga, J. Phys. Chem. 93, 3380 (1990)

    Article  Google Scholar 

  6. N. Ichinose, T. Tanaka, S. Kawanishi, T. Majima, Chem. Phys. Lett. 326, 293 (2000)

    Article  CAS  Google Scholar 

  7. R.S. Mulliken, J. Am. Chem. Soc. 74, 811 (1952)

    Article  CAS  Google Scholar 

  8. S. Inagaki, H. Fujimoto, K. Fukui, J. Am. Chem. Soc. 97, 6108 (1970)

    Article  Google Scholar 

  9. N. Ichinose, T. Tanaka, S. Kawanishi, T. Suzuki, K. Endo, J. Phys. Chem. A 103, 7923 (1999)

    Article  CAS  Google Scholar 

  10. N. Ichinose, T. Majima, Radiat. Chem. Hoshasen-kagaku 72, 31 (2001)

    Google Scholar 

  11. T.M. Bockman, Z.J. Karpinski, S. Sankararaman, J.K. Kochi, J. Am. Chem. Soc. 114, 1970 (1992)

    Article  CAS  Google Scholar 

  12. N. Ichinose, J. Kinugasa, T. Hoshiba, K. Endo, T. Nakayama, to be published

  13. N. Ichinose, J. Kinugasa, T. Hoshiba, K. Endo, T. Nakayama, Chem. Phys. Lett. 363, 270 (2002)

    Article  CAS  Google Scholar 

  14. A. Harriman, J. Chem. Soc., Faraday Trans. 2 77, 1281(1981)

  15. M. Hagiri, N. Ichinose, C. Zhao, H. Horiuchi, H. Hiratsuka, T. Nakayama Chem, Phys. Lett. 391, 297 (2004)

    CAS  Google Scholar 

  16. H.A. Benesi, J.H. Hildebrand, J. Am. Chem. Soc. 71, 2703 (1949)

    Article  CAS  Google Scholar 

  17. S.V. Roskha, S.V. Lindeman, J.K. Kochi, J. Chem. Soc. Perkin, Trans. 2, 1468 (2002)

    Google Scholar 

  18. E. Bosch, J.K. Kochi, J. Org. Chem. 59, 5573 (1994)

    Article  CAS  Google Scholar 

  19. A. Zweig, W.G. Hodgson, W.H. Jura, J. Am. Chem. Soc. 86, 4124 (1964)

    Article  CAS  Google Scholar 

  20. K.Y. Lee, D.J. Kuchynka, J.K. Kochi, Inorg. Chem. 29, 4196 (1990)

    Article  CAS  Google Scholar 

  21. S.J. Strickler, R.A. Berg, J. Chem. Phys. 37, 814 (1962)

    Article  CAS  Google Scholar 

  22. N. Ichinose, T. Majima, Chem. Phys. Lett. 322, 15 (2000)

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Nobuyuki Ichinose.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ichinose, N., Hagiri, M., Kinugasa, Ji. et al. Study on excited states of hexamethoxybenzene-NO+ charge-transfer complex: incorporation of excited radical cation. Res Chem Intermed 39, 425–435 (2013). https://doi.org/10.1007/s11164-012-0660-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11164-012-0660-4

Keywords

Navigation