Anomalous pluse-angle and phase dependence of Hahn's electron spin echo and multiple-quantum echoes of the spin correlated radical pair P700{sup +}A{sub 1}{sup -} in photosystem I.
In a spin-correlated radical pair system, anomalous pulse-angle and phase dependence of electron spin echo and multiple-quantum echoes were theoretically calculated by Tang et al. The maximum intensity of the out of phase signal at 45 degree of spin rotation angle was experimentally verified in two-pulse echoes of the light-induced P700{sup +}A{sub 1-} radical pair in Photosystem I. The values, D = 1.64 G and J = 0.00 G, fit well with the experimental ESEEM spectra. Single and double quantum echoes were observed at the value of t = tau and T = 2tau with the laser flash-t-P1{sub 70,xi1}-tau-P2{sub 140, xi2}-T pulse sequence, which led to determination of the relaxation time T{sub 23} between the singlet and triplet |T0n states. The relaxation times of the zero and single quantum transitions were determined T{sub 23} >> 100 ns and T2 = 1000 ns, respectively. The field sweep ESE signal shape can be fitted with the hyperfine inhomogeneities of 7 G for P700{sup +} and of 10 G for A{sub 1-}.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- ER
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 938124
- Report Number(s):
- ANL/CHM/JA-27218
- Journal Information:
- Appl. Magn. Reson., Journal Name: Appl. Magn. Reson. Journal Issue: 2-3 ; 1998 Vol. 14; ISSN APMREI; ISSN 0937-9347
- Country of Publication:
- United States
- Language:
- ENGLISH
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