Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Inter- and intraband energy transfer in LH2-antenna complexes of purple bacteria. A fluorescence line-narrowing and hole-burning study

Journal Article · · Journal of Physical Chemistry; (United States)
DOI:https://doi.org/10.1021/j100092a032· OSTI ID:6778073
 [1]; ;  [2];  [3]
  1. Univ. of Leiden (Netherlands)
  2. Free Univ., Amsterdam (Netherlands)
  3. Univ. of Leiden (Netherlands) Free Univ., Amsterdam (Netherlands)
High-resolution site-selection fluorescence- and hole-burning spectroscopy were used to study energy transfer in two LH2 light-harvesting complexes of purple bacteria: the B800-850 complex of isolated Rb. sphaeroides and the B800-820 complex of Rps. acidophila, at 1.2 K. Fluorescence spectra, hole widths, and hole depths were measured as a function of excitation wavelength [lambda][sub exc] within the B800 band. For [lambda][sub exc] [>=] 798 nm, fluorescence line-narrowing is observed and the energy-transfer times ([tau] = 2.5 and 2.0 ps for B800-850 and B800-820, respectively) are independent of [lambda][sub exc]. In this spectral region only interband B800 [yields] B850 (B820) energy transfer takes place. For 780 nm [<=] [lambda][sub exc] [<=] 798 nm, the fluorescence bands are broad and the transfer time, obtained from hole widths extrapolated to zero burning-fluorence density, decreases toward the blue side of B800. In this wavelength region competition occurs between B800 [yields] B850 (B820) and B800 [yields] B800 [open quotes]downhill[close quotes] energy transfer. 36 refs., 5 figs.
OSTI ID:
6778073
Journal Information:
Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:41; ISSN JPCHAX; ISSN 0022-3654
Country of Publication:
United States
Language:
English