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Picosecond fluorescence of simple photosynthetic membranes : Evidence of spectral inhomogeneity and directed energy transfer

Pullerits, Tonu LU and Freiberg, Arvi (1991) In Chemical Physics 149(3). p.409-418
Abstract

The picosecond time-domain singlet excitation transfer and trapping kinetics in photosynthetic membranes in case of low excitation intensities is studied by numerical integration of the appropriate master equation. The essential features of our two-dimensional-lattice random walk model are spectral heterogeneity of the light-harvesting antenna, inclusion of temperature effects, nonabsolute excitation trap, correlation between spectral and spatial parameters. A reasonably good agreement between theoretical and experimental fluorescence decay kinetics for purple photosynthetic bacterium Rhodospirillum rubrum is achieved only by assuming relatively large spectral inhomogeneity. From this comparison the average excitation lifetime on the... (More)

The picosecond time-domain singlet excitation transfer and trapping kinetics in photosynthetic membranes in case of low excitation intensities is studied by numerical integration of the appropriate master equation. The essential features of our two-dimensional-lattice random walk model are spectral heterogeneity of the light-harvesting antenna, inclusion of temperature effects, nonabsolute excitation trap, correlation between spectral and spatial parameters. A reasonably good agreement between theoretical and experimental fluorescence decay kinetics for purple photosynthetic bacterium Rhodospirillum rubrum is achieved only by assuming relatively large spectral inhomogeneity. From this comparison the average excitation lifetime on the lattice site is estimated to be 5-8 ps at the effective nearest neighbour lattice distance of 32 Å. If the model is correct, the relatively slow hopping rate determines that excitation transfer and trapping in R. rubrum at active photosynthesis conditions is a diffusion-limited process. The invariably present spectral disorder of photosynthetic systems promoting directed energy transfer serves for higher light-utilizing efficiency.

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author
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publishing date
type
Contribution to journal
publication status
published
in
Chemical Physics
volume
149
issue
3
pages
10 pages
publisher
Elsevier
external identifiers
  • scopus:0001403416
ISSN
0301-0104
DOI
10.1016/0301-0104(91)90040-Z
language
English
LU publication?
no
id
b15cc647-aa90-4752-9cec-2c8dd58f75f5
date added to LUP
2025-08-26 12:09:41
date last changed
2025-09-02 13:36:37
@article{b15cc647-aa90-4752-9cec-2c8dd58f75f5,
  abstract     = {{<p>The picosecond time-domain singlet excitation transfer and trapping kinetics in photosynthetic membranes in case of low excitation intensities is studied by numerical integration of the appropriate master equation. The essential features of our two-dimensional-lattice random walk model are spectral heterogeneity of the light-harvesting antenna, inclusion of temperature effects, nonabsolute excitation trap, correlation between spectral and spatial parameters. A reasonably good agreement between theoretical and experimental fluorescence decay kinetics for purple photosynthetic bacterium Rhodospirillum rubrum is achieved only by assuming relatively large spectral inhomogeneity. From this comparison the average excitation lifetime on the lattice site is estimated to be 5-8 ps at the effective nearest neighbour lattice distance of 32 Å. If the model is correct, the relatively slow hopping rate determines that excitation transfer and trapping in R. rubrum at active photosynthesis conditions is a diffusion-limited process. The invariably present spectral disorder of photosynthetic systems promoting directed energy transfer serves for higher light-utilizing efficiency.</p>}},
  author       = {{Pullerits, Tonu and Freiberg, Arvi}},
  issn         = {{0301-0104}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{3}},
  pages        = {{409--418}},
  publisher    = {{Elsevier}},
  series       = {{Chemical Physics}},
  title        = {{Picosecond fluorescence of simple photosynthetic membranes : Evidence of spectral inhomogeneity and directed energy transfer}},
  url          = {{http://dx.doi.org/10.1016/0301-0104(91)90040-Z}},
  doi          = {{10.1016/0301-0104(91)90040-Z}},
  volume       = {{149}},
  year         = {{1991}},
}