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Low-temperature spectroscopy of bacteriochlorophyll c aggregates

Palecek, David LU ; Dedic, Roman; Alster, Jan and Hala, Jan (2014) In Photosynthesis Research 119(3). p.331-338
Abstract
Chlorosomes from green photosynthetic bacteria belong to the most effective light-harvesting antennas found in nature. Quinones incorporated in bacterichlorophyll (BChl) c aggregates inside chlorosomes play an important redox-dependent photo-protection role against oxidative damage of bacterial reaction centers. Artificial BChl c aggregates with and without quinones were prepared. We applied hole-burning spectroscopy and steady-state absorption and emission techniques at 1.9 K and two different redox potentials to investigate the role of quinones and redox potential on BChl c aggregates at low temperatures. We show that quinones quench the excitation energy in a similar manner as at room temperature, yet the quenching process is not as... (More)
Chlorosomes from green photosynthetic bacteria belong to the most effective light-harvesting antennas found in nature. Quinones incorporated in bacterichlorophyll (BChl) c aggregates inside chlorosomes play an important redox-dependent photo-protection role against oxidative damage of bacterial reaction centers. Artificial BChl c aggregates with and without quinones were prepared. We applied hole-burning spectroscopy and steady-state absorption and emission techniques at 1.9 K and two different redox potentials to investigate the role of quinones and redox potential on BChl c aggregates at low temperatures. We show that quinones quench the excitation energy in a similar manner as at room temperature, yet the quenching process is not as efficient as for chlorosomes. Interestingly, our data suggest that excitation quenching partially proceeds from higher excitonic states competing with ultrafast exciton relaxation. Moreover, we obtained structure-related parameters such as reorganization energies and inhomogeneous broadening of the lowest excited state, providing experimental ground for theoretical studies aiming at designing plausible large-scale model for BChl c aggregates including disorder. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Artificial light-harvesting, Bacteriochlorophyll aggregates, Excitation, quenching, Hole-burning, Low-temperature spectroscopy, Quinone
in
Photosynthesis Research
volume
119
issue
3
pages
331 - 338
publisher
Springer
external identifiers
  • wos:000331720100007
  • scopus:84894459796
ISSN
0166-8595
DOI
10.1007/s11120-013-9955-6
language
English
LU publication?
yes
id
d73d3e2a-d861-44cd-a777-f215e102c4ad (old id 4364072)
date added to LUP
2014-04-22 14:40:52
date last changed
2017-01-01 05:59:16
@article{d73d3e2a-d861-44cd-a777-f215e102c4ad,
  abstract     = {Chlorosomes from green photosynthetic bacteria belong to the most effective light-harvesting antennas found in nature. Quinones incorporated in bacterichlorophyll (BChl) c aggregates inside chlorosomes play an important redox-dependent photo-protection role against oxidative damage of bacterial reaction centers. Artificial BChl c aggregates with and without quinones were prepared. We applied hole-burning spectroscopy and steady-state absorption and emission techniques at 1.9 K and two different redox potentials to investigate the role of quinones and redox potential on BChl c aggregates at low temperatures. We show that quinones quench the excitation energy in a similar manner as at room temperature, yet the quenching process is not as efficient as for chlorosomes. Interestingly, our data suggest that excitation quenching partially proceeds from higher excitonic states competing with ultrafast exciton relaxation. Moreover, we obtained structure-related parameters such as reorganization energies and inhomogeneous broadening of the lowest excited state, providing experimental ground for theoretical studies aiming at designing plausible large-scale model for BChl c aggregates including disorder.},
  author       = {Palecek, David and Dedic, Roman and Alster, Jan and Hala, Jan},
  issn         = {0166-8595},
  keyword      = {Artificial light-harvesting,Bacteriochlorophyll aggregates,Excitation,quenching,Hole-burning,Low-temperature spectroscopy,Quinone},
  language     = {eng},
  number       = {3},
  pages        = {331--338},
  publisher    = {Springer},
  series       = {Photosynthesis Research},
  title        = {Low-temperature spectroscopy of bacteriochlorophyll c aggregates},
  url          = {http://dx.doi.org/10.1007/s11120-013-9955-6},
  volume       = {119},
  year         = {2014},
}