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Femtosecond energy transfer within the LH2 peripheral antenna of the photosynthetic purple bacteria Rhodobacter sphaeroides and Rhodopseudomonas palustris LL

Hess, Sussan ; Feldchtein, Felix ; Babin, Alexey ; Nurgaleev, Ildus ; Pullerits, Tonu LU ; Sergeev, Alexander and Sundström, Villy LU (1993) In Chemical Physics Letters 216(3-6). p.247-257
Abstract

The ultrafast energy transfer among the pigments of the B800-850 membrane antenna pigment-protein complex of the photosynthetic purple bacteria Rhodobacter sphaeroides and Rhodopseudomonas palustris LL has been studied with ≈ 100 fs tunable infrared pulses at room temperature and 77 K. It is shown that the B800→B850 transfer time is similar in both species and occurs with a characteristic time constant of 0.6-0.8 ps at room temperature and 2.4-2.6 ps at 77 K. Measurements of absorption anisotropy in the 800 nm band shows that the depolarizing energy transfer among B800 molecules is slower than the B800→B850 transfer. At room temperature such a transfer occurs with a time constant of 0.8-1.6 ps and at 77 K with a time constant much... (More)

The ultrafast energy transfer among the pigments of the B800-850 membrane antenna pigment-protein complex of the photosynthetic purple bacteria Rhodobacter sphaeroides and Rhodopseudomonas palustris LL has been studied with ≈ 100 fs tunable infrared pulses at room temperature and 77 K. It is shown that the B800→B850 transfer time is similar in both species and occurs with a characteristic time constant of 0.6-0.8 ps at room temperature and 2.4-2.6 ps at 77 K. Measurements of absorption anisotropy in the 800 nm band shows that the depolarizing energy transfer among B800 molecules is slower than the B800→B850 transfer. At room temperature such a transfer occurs with a time constant of 0.8-1.6 ps and at 77 K with a time constant much longer than the excited state lifetime. A fast ≈ 300 fs non-depolarizing, almost temperature-independent, relaxation process is also observed within the B800 band. Energy transfer between a pair of almost parallel B800 molecules and possibly also vibrational relaxation are discussed as the possible origins of this process.

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publishing date
type
Contribution to journal
publication status
published
in
Chemical Physics Letters
volume
216
issue
3-6
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:0001371891
ISSN
0009-2614
DOI
10.1016/0009-2614(93)90090-N
language
English
LU publication?
no
id
ace571d9-fd04-4275-a6be-294ed09fe980
date added to LUP
2025-09-09 12:10:33
date last changed
2025-10-14 11:25:18
@article{ace571d9-fd04-4275-a6be-294ed09fe980,
  abstract     = {{<p>The ultrafast energy transfer among the pigments of the B800-850 membrane antenna pigment-protein complex of the photosynthetic purple bacteria Rhodobacter sphaeroides and Rhodopseudomonas palustris LL has been studied with ≈ 100 fs tunable infrared pulses at room temperature and 77 K. It is shown that the B800→B850 transfer time is similar in both species and occurs with a characteristic time constant of 0.6-0.8 ps at room temperature and 2.4-2.6 ps at 77 K. Measurements of absorption anisotropy in the 800 nm band shows that the depolarizing energy transfer among B800 molecules is slower than the B800→B850 transfer. At room temperature such a transfer occurs with a time constant of 0.8-1.6 ps and at 77 K with a time constant much longer than the excited state lifetime. A fast ≈ 300 fs non-depolarizing, almost temperature-independent, relaxation process is also observed within the B800 band. Energy transfer between a pair of almost parallel B800 molecules and possibly also vibrational relaxation are discussed as the possible origins of this process.</p>}},
  author       = {{Hess, Sussan and Feldchtein, Felix and Babin, Alexey and Nurgaleev, Ildus and Pullerits, Tonu and Sergeev, Alexander and Sundström, Villy}},
  issn         = {{0009-2614}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{3-6}},
  pages        = {{247--257}},
  publisher    = {{Elsevier}},
  series       = {{Chemical Physics Letters}},
  title        = {{Femtosecond energy transfer within the LH2 peripheral antenna of the photosynthetic purple bacteria <i>Rhodobacter sphaeroides</i> and <i>Rhodopseudomonas palustris</i> LL}},
  url          = {{http://dx.doi.org/10.1016/0009-2614(93)90090-N}},
  doi          = {{10.1016/0009-2614(93)90090-N}},
  volume       = {{216}},
  year         = {{1993}},
}