High-pressure hole-burning studies of the bacteriochlorophyll a antenna complex from Chlorobium tepidum
Journal Article
·
· Journal of Physical Chemistry
- Ames Lab., IA (United States)
The dependence of the low-temperature Q{sub y} absorption and nonphotochemical hole-burned spectra of the title complex (also known as the FMO complex) on pressure (<= 700 MPa) is reported. Pressure-induced structural changes of the complex were found to be elastic. The linear pressure shifts at 4.2 K for the principal absorption bands at 805, 814 and 825 nm are -0.08, -0.11, and -0.11 cm{sup -1}/MPa, respectively. Importantly, the 825 and 814 nm absorption profiles (shape, intensity) are independent of pressure. The results establish that, even at the highest values used, pressure has only a weak effect on the pairwise excitonic couplings of the bacteriochlorophyll (BChl) molecules, inhomogeneous broadening, and electron-phonon coupling. The pressure dependence of the Q{sub y} spectrum and zero-phonon holes (ZPH) burned in the 825 nm band can be rationalized in terms of dispersion interactions when BChl occupation numbers for the exciton levels are taken into account. These ZPH, which are assigned to the lowest level at 827 nm, carry a width of 0.6 cm{sup -1} at 4.2 K, which is independent of the pressure at which the hole is burned. This width is ascribed to dephasing, T{sub 2} = 35 ps. Possible mechanisms for the dephasing are considered, and its pressure independence is discussed. 80 refs., 12 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 159719
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 43 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
Similar Records
Excited-state structure and energy-transfer dynamics of the bacteriochlorophyll a antenna complex from Prosthecochloris aestuarii
Energy transfer and spectral dynamics of the three lowest energy Q{sub y}-states of the Fenna-Matthews-Olson antenna complex
Q{sub y}-level structure and dynamics of solubilized light-harvesting complex 2 of green plants: Pressure and hole burning studies
Journal Article
·
Wed Jan 09 23:00:00 EST 1991
· Journal of Physical Chemistry; (USA)
·
OSTI ID:5796318
Energy transfer and spectral dynamics of the three lowest energy Q{sub y}-states of the Fenna-Matthews-Olson antenna complex
Journal Article
·
Thu Jul 08 00:00:00 EDT 1999
· Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
·
OSTI ID:682111
Q{sub y}-level structure and dynamics of solubilized light-harvesting complex 2 of green plants: Pressure and hole burning studies
Journal Article
·
Thu Apr 08 00:00:00 EDT 1999
· Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory
·
OSTI ID:338459