Applied Magnetic Resonance

, 3:199 | Cite as

Peculiarities of free induction and primary spin echo signals for spin-correlated radical pairs

  • K. M. Salikhov
  • Yu. E. Kandrashkin
  • A. K. Salikhov


Keeping in mind ion-radical pairs in a photosynthesis reaction centre first of all, we calculated free induction and spin echo (ESE) signals for an ensemble of radical pairs which initially start in a singlet state. It was shown that the intensity of signals should oscillate depending on the time interval τ between the start of a pair and a microwave pulse forming free induction (FI) or between the start of a pair and the first of two microwave pulses forming primary ESE signal. ESE phase of spin-correlated pairs does not coincide with the corresponding ESE phase of radical pairs in thermal equilibrium. One should also note an interesting feature of FI: immediately after the microwave pulse free induction signal equals zero, and non-zero free induction signal appears only due to spin evolution. This behaviour formally resembles the situation occurring when the primary ESE is formed: a light pulse which creates spin-correlated radical pairs acts as the first microwave pulse in conventional spin echo experiments. Analysis of FI and ESE in experiments on pulse photolysis or radiolysis may provide useful information about the contribution of spin-correlated radical pairs.


Microwave Pulse Frequency Spread Primary Spin Echo Signal Pulse Photolysis 
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.


  1. [1]
    Salikhov K.M., Molin Yu.N., Sagdeev R.Z., Buchachenko A.L.: Spin Polarization and Magnetic Effects in Radical Reactions. Amsterdam, New York: Elsevier 1984.Google Scholar
  2. [2]
    Ernst R.R., Bodenhausen G., Wokaun A.: Principles of Nuclear Magnetic Resonance in One and Two Dimensions. Oxford, England: Oxford Univ. Press 1987.Google Scholar
  3. [3]
    McLauchlan K.A. in: Advanced EPR. Applications in Biology and Biochemistry (Hoff A.J. ed.), chap. 10. Amsterdam-Oxford-New York-Tokyo:Elsevier 1989.Google Scholar
  4. [4]
    Stehlik D., Bock C.H., Thurnauer M.C. in: Advanced EPR. Applications in Biology and Biochemistry (Hoff A.J. ed.), chap. 11. Amsterdam-Oxford-New York-Tokyo: Elsevier 1989.Google Scholar
  5. [5]
    Thurnauer M.C., Norris J.R.: Chem. Rhys. Lett.76, 557–561 (1980)CrossRefADSGoogle Scholar
  6. [6]
    Salikhov K.M., Bock C.H., Stehlik D.: Appl. Magn. Res.1, 195–211 (1990)CrossRefGoogle Scholar
  7. [7]
    Kothe G., Weber S., Bittl R., Norris J., Snyder S.S., Tang J., Thurnauer M.C. in: Spin Chemistry (I’Haya Y.J. ed.), p. 420–434. Tokyo Univ.: Japan 1991.Google Scholar
  8. [8]
    Dinse K.-P., Kroll G., Plüschau M., Beckert D. in: Spin Chemistry (I’Haya Y.J. ed.), p. 344–352. Tokyo Univ.: Japan 1991.Google Scholar
  9. [9]
    Angerhofer A., Wasielewski M.R., Gaines III G.L., O’Neil M.P., Svec W.A., Niemczyk M.P.: Fourier-Transform EPR on Model Systems of the Primary Change Separation in Photosynthesis (in press).Google Scholar
  10. [10]
    Salikhov K.M.: (in press).Google Scholar
  11. [11]
    Korolenko E.C., Shokhirev N.V., Salikhov K.M., Sagdeev R.Z.: Chem. Phys.131, 315–323 (1989)CrossRefGoogle Scholar

Copyright information

© Springer 1992

Authors and Affiliations

  • K. M. Salikhov
    • 1
  • Yu. E. Kandrashkin
    • 2
  • A. K. Salikhov
    • 2
  1. 1.Kazan Physical-Technical InstituteKazanThe Russian Federation
  2. 2.Kazan State UniversityKazanRussian Federation

Personalised recommendations