Relaxation dynamics of the LH2 complex from a photosynthetic purple bacteriumThiorhodospira sibiricastudied by the near-IR femtosecond pump-probe method
| Autor: | V S Kozlovskii, Andrei P. Razjivin, R. Yu. Pishchalnikov, Sergei V Chekalin, Z. K. Makhneva, Andrei A. Moskalenko, V. O. Kompanets |
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| Rok vydání: | 2005 |
| Předmět: |
Materials science
Absorption spectroscopy biology Relaxation (NMR) Analytical chemistry Statistical and Nonlinear Physics biology.organism_classification Purple bacteria Atomic and Molecular Physics and Optics Spectral line Electronic Optical and Magnetic Materials chemistry.chemical_compound Nuclear magnetic resonance chemistry Picosecond Femtosecond Bacteriochlorophyll Electrical and Electronic Engineering Thiorhodospira sibirica |
| Zdroj: | Quantum Electronics. 35:107-110 |
| ISSN: | 1468-4799 1063-7818 |
| DOI: | 10.1070/qe2005v035n01abeh002880 |
| Popis: | Photoinduced changes in the absorption spectrum of the LH2 (B800-830-850) complex from a Thiorhodospira sibirica (Trs. sibirica) bacterium are studied by the pump-probe method. The complex has the anomalous absorption spectrum exhibiting three bands in the near-IR region at 793, 826.5, and 846.5 nm. At room temperature, the excitation energy transfer from the B800, B830, and B859 bands was detected with the time constants τ1~0.5 ps, τ2~2.5 ps, and τ3 of the order of a few hundreds of picoseconds, respectively. A rapid energy transfer from the B830 band compared to energy transfer from the B850 band (τ2τ3) suggests that all the three bands belong to the same complex (i.e., that the LH2 complex from Trs. sibirica is homogeneous). A slower energy transfer (by three — five times) from the B830 band of the LH2 complex from Trs. sibirica compared to energy transfer from the B800 band of the LH2 complexes (B800-850 and especially B800-820) from other purple bacteria suggests that the electronic structures of ensembles of bacteriochlorophyll molecules in these complexes are substantially different. |
| Databáze: | OpenAIRE |
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