Exciton dynamics in LH1 and LH2 of Rhodopseudomonas acidophila and Rhodobium marinum probed with accumulated photon echo and pump-probe measurements
| Autor: | Douwe A. Wiersma, Ivo H. M. van Stokkum, Rienk van Grondelle, Richard J. Cogdell, Koos Duppen, Stefania S. Lampoura |
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| Přispěvatelé: | Biophysics Photosynthesis/Energy, Physical Computer Science |
| Jazyk: | angličtina |
| Rok vydání: | 2000 |
| Předmět: |
Photon
food.ingredient Exciton Dephasing RHODOBACTER-SPHAEROIDES Photochemistry Molecular physics Light-harvesting complex Rhodobacter sphaeroides food LOW-TEMPERATURE ANTENNA COMPLEXES Materials Chemistry Physical and Theoretical Chemistry PICOSECOND ABSORPTION-SPECTROSCOPY LIGHT-HARVESTING COMPLEX PHOTOSYNTHETIC PURPLE BACTERIA ENERGY-TRANSFER DYNAMICS PIGMENT-PROTEIN COMPLEXES biology Chemistry RHODOSPIRILLUM-RUBRUM Rhodopseudomonas biology.organism_classification Surfaces Coatings and Films Wavelength BACTERIOCHLOROPHYLL ANTENNA Picosecond |
| Zdroj: | Journal of Physical Chemistry B, 104, 12072-12078. American Chemical Society The Journal of Physical Chemistry B, 104(50), 12072-12078. AMER CHEMICAL SOC Lampoura, S, van Grondelle, R, van Stokkum, I H M, Cogdell, R J, Wiersma, D A & Duppen, K 2000, ' Exciton dynamics in LH1 and LH2 of Rhodopseudomonas acidophila and Rhodobium marinum probed with accumulated photon echo and pump-probe measurements ', Journal of Physical Chemistry B, vol. 104, pp. 12072-12078 . https://doi.org/10.1021/jp0021289 |
| ISSN: | 1520-6106 1520-5207 |
| DOI: | 10.1021/jp0021289 |
| Popis: | Exciton dynamics in the B850 and B875 bands of isolated complexes of Rhodopseudomonas acidophila (strain 10050 and 7050) and in the B875 band of isolated complexes of Rhodobium marinum were investigated by means of accumulated photon echo and pump-probe techniques at different temperatures and wavelengths. For all three systems, the optical dephasing time T2 was found to be very similar: at 4.2 K, T2 is 116 and 106 ps for the B850 and B875 bands of Rhodopseudomonas acidophila, respectively, and 93 ps for the B875 band of Rhodobium marinum. The rapid dephasing, which displays glassy character, is a consequence of the strong pigment-protein interactions that arise through the rather short distances in these complexes. The observed dephasing time at the red edge of the B850 band of Rhodopseudomonas acidophila at 4.2 K reveals the existence of spectral diffusion in this system. From the wavelength dependence of the pump-probe signal in the B875 LH1 band of Rhodopseudomonas acidophila at 3 K it is concluded that energy transfer between energetically inequivalent LH1 rings occurs on a time scale of several tens picoseconds, while energy trapping takes place in about 250 ps. |
| Databáze: | OpenAIRE |
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