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Coherent Picosecond Exciton Dynamics in a Photosynthetic Reaction Center

Westenhoff, Sebastian; Palecek, David LU ; Edlund, Petra; Smith, Philip and Zigmantas, Donatas LU (2012) In Journal of the American Chemical Society 134(40). p.16484-16487
Abstract
Photosynthetic reaction centers convert sunlight into a transmembrane electrochemical potential difference, providing chemical energy to almost all life on earth. Light energy is efficiently transferred through chromophore cofactors to the sites, where charge separation occurs. We applied two-dimensional electronic spectroscopy to assess the role of coherences in the photoresponse of the bacterial reaction center of Rhodobacter sphaeroides. By controlling the polarization of the laser beams, we were able to assign unambiguously the oscillatory dynamics to electronic (intermolecular) coherences. The data show that these coherences are sustained for more than 1 ps, indicating that the protein coherently retains some excitation energy on this... (More)
Photosynthetic reaction centers convert sunlight into a transmembrane electrochemical potential difference, providing chemical energy to almost all life on earth. Light energy is efficiently transferred through chromophore cofactors to the sites, where charge separation occurs. We applied two-dimensional electronic spectroscopy to assess the role of coherences in the photoresponse of the bacterial reaction center of Rhodobacter sphaeroides. By controlling the polarization of the laser beams, we were able to assign unambiguously the oscillatory dynamics to electronic (intermolecular) coherences. The data show that these coherences are sustained for more than 1 ps, indicating that the protein coherently retains some excitation energy on this time scale. Our finding provides a mechanism for effective delocalization of the excitations on the picosecond time scale by electronic coherence, setting the stage for efficient charge separation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Chemical Society
volume
134
issue
40
pages
16484 - 16487
publisher
The American Chemical Society
external identifiers
  • wos:000309566400010
  • scopus:84867391111
ISSN
1520-5126
DOI
10.1021/ja3065478
language
English
LU publication?
yes
id
ba0284a4-ef3d-4037-a84b-84dcd1d46a04 (old id 3181386)
date added to LUP
2012-12-06 15:00:01
date last changed
2017-11-12 03:47:44
@article{ba0284a4-ef3d-4037-a84b-84dcd1d46a04,
  abstract     = {Photosynthetic reaction centers convert sunlight into a transmembrane electrochemical potential difference, providing chemical energy to almost all life on earth. Light energy is efficiently transferred through chromophore cofactors to the sites, where charge separation occurs. We applied two-dimensional electronic spectroscopy to assess the role of coherences in the photoresponse of the bacterial reaction center of Rhodobacter sphaeroides. By controlling the polarization of the laser beams, we were able to assign unambiguously the oscillatory dynamics to electronic (intermolecular) coherences. The data show that these coherences are sustained for more than 1 ps, indicating that the protein coherently retains some excitation energy on this time scale. Our finding provides a mechanism for effective delocalization of the excitations on the picosecond time scale by electronic coherence, setting the stage for efficient charge separation.},
  author       = {Westenhoff, Sebastian and Palecek, David and Edlund, Petra and Smith, Philip and Zigmantas, Donatas},
  issn         = {1520-5126},
  language     = {eng},
  number       = {40},
  pages        = {16484--16487},
  publisher    = {The American Chemical Society},
  series       = {Journal of the American Chemical Society},
  title        = {Coherent Picosecond Exciton Dynamics in a Photosynthetic Reaction Center},
  url          = {http://dx.doi.org/10.1021/ja3065478},
  volume       = {134},
  year         = {2012},
}