Applied Magnetic Resonance

, Volume 20, Issue 1–2, pp 111–135 | Cite as

Spin dynamics in strongly coupled spin-correlated radical pairs: Stochastic modulation of the exchange interaction and ST−1 mixing in different magnetic fields

  • A. Osintsev
  • A. Popov
  • M. Fuhs
  • K. Möbius
Article
Received:

Abstract

We investigate the effect of stochastic modulation of the exchange interaction Jex on singlet (S)-triplet (T) transitions in radical pairs. These transitions limit the lifetime of the photo-generated radical pairs in covalently linked porphyrin-quinone systems that have been developed for biomimetic modeling of photosynthetic electron transfer processes. In order to explain transient electron paramagnetic resonance (EPR) results in different magnetic fields, i.e., with X-band ((0.34 T)/ (9.5 GHz)) and W-band ((3.4 T)/(95 GHz)) time-resolved EPR, we have to assume that Jex is modulated over a range of 20000 G, which is wide enough that S is temporarily almost degenerate with T0 as well as with T−1. This large modulation of Jex is caused by restricted rotational diffusion of the quinone subunit with respect to the porphyrin subunit. However, because of the small interradical distance of about 1.0–1.4 nm, the radical pair is continuously kept in the strong coupling limit and, therefore, we observe only EPR transition between the triplet sublevels. We find an approximation to solve the stochastic Liouville equation valid for rotational diffusion on an intermediate time scale, i.e., the diffusion rate DR is smaller than the singlet electron recombination rate KS ∼ 109 s−1, but larger than the ST transition rates κ0, κ−1 < 106 s−1.

Keywords

Radical Pair Rotational Diffusion Stochastic Modulation Intermediate Time Scale TREPR Spectrum 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Stehlik D., Möbius K.: Annu. Rev. Phys. Chem.48, 745 (1997)CrossRefGoogle Scholar
  2. 2.
    Hoff A.J., Deisenhofer J.: Phys. Rep.287, 1 (1997)CrossRefADSGoogle Scholar
  3. 3.
    Schlüpmann J., Lendzian F., Plato M., Möbius K.: J. Chem. Soc. Faraday Trans.89, 2853 (1993)CrossRefGoogle Scholar
  4. 4.
    Elger G., Kurreck H., Wiehe A., Johnen E., Fuhs M., Prisner T., Vrieze J.: Acta Chem. Scand.51, 593 (1997)CrossRefGoogle Scholar
  5. 5.
    Elger G., Fuhs M., Müller P., von Gersdorff J., Wiehe A., Kurreck H., Möbius K.: Mol. Phys.95, 1309 (1998)ADSGoogle Scholar
  6. 6.
    Fuhs M., Elger G., Osintsev A., Popov A., Kurreck H., Möbius K.: Mol. Phys.98, 1025 (2000)CrossRefADSGoogle Scholar
  7. 7.
    Kurreck H., Huber M.: Angew. Chem. Int. Ed. Engl.34, 949 (1995)CrossRefGoogle Scholar
  8. 8.
    von Gersdorff J., Huber M., Schubert H., Niethammer D., Kirste B., Plato M., Möbius K., Kurreck H., Eichberger R., Kietzmann R., Willig F.: Angew. Chem. Int. Ed. Engl.29, 670 (1990)CrossRefGoogle Scholar
  9. 9.
    Dieks H., Sobek J., Tian P., Kurreck H.: Tetrahedron Lett.33, 5951 (1992)CrossRefGoogle Scholar
  10. 10.
    Wiehe A., Senge M.O., Kurreck H.: Lieb. Ann. Recueil.9, 1951 (1997)CrossRefGoogle Scholar
  11. 11.
    Fuhs M., von Gersdorff J., Dieks H., Kurreck H., Möbius K., Prisner T.: J. Chem. Soc. Faraday Trans.92, 949 (1996)CrossRefGoogle Scholar
  12. 12.
    Freed J.H., Pedersen J.B.: Adv. Magn. Reson.8, 1 (1976)Google Scholar
  13. 13.
    Salikhov K.M., Molin Y.N., Sagdeev R.Z., Buchachenko A.L.: Spin Polarization and Magnetic Effects in Radical Reactions. Amsterdam: Elsevier 1984.Google Scholar
  14. 14.
    Adrian F.J., Monchick L.: J. Chem. Phys.71, 2600 (1979)CrossRefADSGoogle Scholar
  15. 15.
    Shushin A.I.: Chem. Phys.144, 201 (1990)CrossRefADSGoogle Scholar
  16. 16.
    Avdievich N.I., Forbes M.D.E.: J. Phys. Chem.99, 9660 (1995)CrossRefGoogle Scholar
  17. 17.
    Avdievich N.I., Dukes K.E., Forbes M.D.E., DeSimone J.M.: J. Phys. Chem. A101, 617 (1997)CrossRefGoogle Scholar
  18. 18.
    Salikhov K., Schlüpmann J., Plato M., Möbius K.: Chem. Phys.215, 23 (1997)CrossRefGoogle Scholar
  19. 19.
    Fajer J., Barkigia K.M., Melamed D., Sweet R.M., Kurreck H., von Gersdorff J., Plato M., Rohland H.-C., Elger G., Möbius K.: J. Phys. Chem.100, 14236 (1996)CrossRefGoogle Scholar
  20. 20.
    Hore P.J. in: Advanced EPR, Applications in Biology and Biochemistry (Hoff A.J., ed.), chap. 12. Amsterdam: Elsevier 1989.Google Scholar
  21. 21.
    Evans G.T., Fleming P.D., Lawler R.G.: J. Chem. Phys.58, 2071 (1973)CrossRefADSGoogle Scholar
  22. 22.
    Pedersen J.B., Freed J.H.: J. Chem. Phys.61, 1517 (1974)CrossRefADSGoogle Scholar
  23. 23.
    Purtov P.A., Doktorov A.B.: Chem. Phys.178, 47 (1993)CrossRefADSGoogle Scholar
  24. 24.
    Mathews J., Walker R.L.: Mathematical Methods of Physics. Menlo Park: Benjamin W.A. 1964.MATHGoogle Scholar
  25. 25.
    Doktorov A.B., Burshtein A.I.: Zh. Teor. Eksp. Fiz.68, 1349 (1975)Google Scholar
  26. 26.
    Doktorov A.B.: Physica A90, 109 (1978)CrossRefADSMathSciNetGoogle Scholar
  27. 27.
    Eyring H., Lin S.H., Lin S.M.: Basic Chemical Kinetics, p. 18. New York: Wiley 1980.Google Scholar
  28. 28.
    Zharikov A.A., Shokhirev N.V.: Z. Physik. Chem.37, 177 (1992)Google Scholar
  29. 29.
    Adrian F.J.: J. Chem. Phys.102, 4409 (1995)CrossRefADSGoogle Scholar
  30. 30.
    Popov A.V., Purtov P.A.: Chem. Phys. Rep.16, 27 (1997)Google Scholar
  31. 31.
    Steiner U.E., Ulrich T.: Chem. Rev.89, 51 (1989)CrossRefGoogle Scholar
  32. 32.
    Sasaki S., Katsuki A., Akiyama K., Ikegami Y., Tero-Kubota S.: J. Am. Chem. Soc.119, 1323 (1997)CrossRefGoogle Scholar
  33. 33.
    Poole C.P.: Electron Spin Resonance, p. 811. New York: Wiley 1967.Google Scholar
  34. 34.
    Whiting E.E.: J. Quant. Spectrosc. Radiat. Transf.18, 1379 (1968)CrossRefADSGoogle Scholar
  35. 35.
    Burghaus O., Plato M., Rohrer M., Möbius K., MacMillan F., Lubitz W.: J. Phys. Chem.97, 7639 (1993)CrossRefGoogle Scholar
  36. 36.
    van der Est A.J., Fuechsle G., Stehlik D., Wasielewski M.R.: Ber. Bunsenges. Phys. Chem.100, 1082 (1996)Google Scholar
  37. 37.
    Herring C., Flicker M.: Phys. Rev.134 (1964)Google Scholar
  38. 38.
    Closs G.L., Miller J.R.: Science240, 440 (1988)CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • A. Osintsev
    • 1
  • A. Popov
    • 1
  • M. Fuhs
    • 2
  • K. Möbius
    • 2
  1. 1.Kemerovo Technological InstituteKemerovoRussian Federation
  2. 2.Institute of Experimental PhysicsFree University BerlinBerlinGermany

Personalised recommendations