Femtosecond spectroscopy of chlorosome antennas from the green photosynthetic bacterium Chloroflexus aurantiacus
- Iowa State Univ., Ames, IA (United States) Ames Lab., IA (United States)
- Arizona State Univ., Tempe, AZ (United States)
The antenna kinetics of bacteriochlorophyll (BChl) c- and a-containing chromosomes from the thermophilic filamentous green photosynthetic bacterium Chloroflexus aurantiacus were investigated using two independent pump-probe techniques with subpicosecond resolution. Isotropic one- and two-color absorption difference experiments using probe wavelengths between 710 and 770 nm reveal BChl c photobleaching (PB) and stimulated emission (SE) decay kinetics with major lifetime components of 50-100 fs, 1-2 ps, and 7-10 ps. Two-color PB.SE profiles pumped at 770 nm and probed at 800 nm (where BChl a pigments absorb) exhibit no detectable rise time. However, two-color experiments using 790 and 820 nm pump and probe wavelengths, respectively, yield PB/SE rise components of 100 fs, 2 ps, and 10 ps. Upon excitation at 720 nm, the BCHl c PB/SE spectrum observed using a broad-band probe continuum displays surprisingly little spectral evolution during the first 2 ps. 65 refs., 13 figs., 3 tabs.
- OSTI ID:
- 6842171
- Journal Information:
- Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:40; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
140505* -- Solar Energy Conversion-- Photochemical
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400500 -- Photochemistry
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANISOTROPY
BACTERIA
BIOLOGICAL MATERIALS
CARBOXYLIC ACIDS
CHLOROPHYLL
COMPILED DATA
DATA
FLUORESCENCE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
ISOTROPY
LASERS
LUMINESCENCE
MATERIALS
MICROORGANISMS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOSYNTHETIC BACTERIA
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
SPECTROSCOPY