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Title: Mechanism of energy transfer from carotenoids to bacteriochlorophyll : light-harvesting by carotenoids having different extents of {pi}-electron conjugation incorporated into the B850 antenna complex from the carotenoidless bacterium Rhodobacter sphaeroides R-26.1.

Abstract

Spheroidene and a series of spheroidene analogues with extents of p-electron conjugation ranging from 7 to 13 carbon-carbon double bonds were incorporated into the B850 light-harvesting complex of Rhodobacter sphaeroides R-26.1. The structures and spectroscopic properties of the carotenoids and the dynamics of energy transfer from the carotenoid to bacteriochlorophyll (BChl) in the B850 complex were studied by using steady-state absorption, fluorescence, fluorescence excitation, resonance Raman, and time-resolved absorption spectroscopy. The spheroidene analogues used in this study were 5',6'-dihydro-7',8'-didehydrospheroidene, 7',8'-didehydrospheroidene, and 1',2'-dihydro-3',4',7',8'-tetradehydrospheroidene. These data, taken together with results from 3,4,7,8-tetrahydrospheroidene, 3,4,5,6-tetrahydrospheroidene, 3,4-dihydrospheroidene, and spheroidene already published (Frank, H. A.; Farhoosh, R.; Aldema, M. L.; DeCoster, B.; Christensen, R. L.; Gebhard, R.; Lugtenburg, J. Photochem. Photobiol. 1993, 57, 49. Farhoosh, R.; Chynwat, V.; Gebhard, R.; Lugtenburg, J.; Frank, H. A. Photosynth. Res. 1994, 42, 157), provide a systematic series of molecules for understanding the molecular features that determine the mechanism of energy transfer from carotenoids to BChl in photosynthetic bacterial light-harvesting complexes. The data support the hypothesis that only carotenoids having 10 or less carbon-carbon double bonds transfer energy via their 21Ag (S1) states to BChl to any significant degree. Energy transfer via the 11Bu (S2) state of the carotenoid becomesmore » more important than the S1 route as the number of conjugated carbon-carbon double bonds increases. The results also suggest that the S2 state associated with the Qx transition of the B850 BChl is the most likely acceptor state for energy transfer originating from both the 2{sup 1}A{sub g} (S{sub 1}) and 1{sup 1}B{sub u} (S{sub 2}) states of all carotenoids.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
ER
OSTI Identifier:
938357
Report Number(s):
ANL/CHM/JA-29681
Journal ID: ISSN 1089-5647; JPCBFK; TRN: US200908%%209
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Phys. Chem. B; Journal Volume: 102; Journal Issue: 42 ; Oct. 15, 1998
Country of Publication:
United States
Language:
ENGLISH
Subject:
14 SOLAR ENERGY; 59 BASIC BIOLOGICAL SCIENCES; CAROTENOIDS; ENERGY TRANSFER; BACTERIA; PHOTOSYNTHESIS; CHLOROPHYLL

Citation Formats

Desamero, R. Z. B., Chynwat, V., van der Hoef, I., Jansen, F. J., Lugtenburg, J., Gosztola, D., Wasielewski, M. R., Cua, A., Bocian, D. F., Frank, H. A., Univ. of Connecticut, Leiden Univ., Northwestern Univ., Univ. of California, and Univ. of connecticut. Mechanism of energy transfer from carotenoids to bacteriochlorophyll : light-harvesting by carotenoids having different extents of {pi}-electron conjugation incorporated into the B850 antenna complex from the carotenoidless bacterium Rhodobacter sphaeroides R-26.1.. United States: N. p., 1998. Web. doi:10.1021/jp980911j.
Desamero, R. Z. B., Chynwat, V., van der Hoef, I., Jansen, F. J., Lugtenburg, J., Gosztola, D., Wasielewski, M. R., Cua, A., Bocian, D. F., Frank, H. A., Univ. of Connecticut, Leiden Univ., Northwestern Univ., Univ. of California, & Univ. of connecticut. Mechanism of energy transfer from carotenoids to bacteriochlorophyll : light-harvesting by carotenoids having different extents of {pi}-electron conjugation incorporated into the B850 antenna complex from the carotenoidless bacterium Rhodobacter sphaeroides R-26.1.. United States. doi:10.1021/jp980911j.
Desamero, R. Z. B., Chynwat, V., van der Hoef, I., Jansen, F. J., Lugtenburg, J., Gosztola, D., Wasielewski, M. R., Cua, A., Bocian, D. F., Frank, H. A., Univ. of Connecticut, Leiden Univ., Northwestern Univ., Univ. of California, and Univ. of connecticut. Thu . "Mechanism of energy transfer from carotenoids to bacteriochlorophyll : light-harvesting by carotenoids having different extents of {pi}-electron conjugation incorporated into the B850 antenna complex from the carotenoidless bacterium Rhodobacter sphaeroides R-26.1.". United States. doi:10.1021/jp980911j.
@article{osti_938357,
title = {Mechanism of energy transfer from carotenoids to bacteriochlorophyll : light-harvesting by carotenoids having different extents of {pi}-electron conjugation incorporated into the B850 antenna complex from the carotenoidless bacterium Rhodobacter sphaeroides R-26.1.},
author = {Desamero, R. Z. B. and Chynwat, V. and van der Hoef, I. and Jansen, F. J. and Lugtenburg, J. and Gosztola, D. and Wasielewski, M. R. and Cua, A. and Bocian, D. F. and Frank, H. A. and Univ. of Connecticut and Leiden Univ. and Northwestern Univ. and Univ. of California and Univ. of connecticut},
abstractNote = {Spheroidene and a series of spheroidene analogues with extents of p-electron conjugation ranging from 7 to 13 carbon-carbon double bonds were incorporated into the B850 light-harvesting complex of Rhodobacter sphaeroides R-26.1. The structures and spectroscopic properties of the carotenoids and the dynamics of energy transfer from the carotenoid to bacteriochlorophyll (BChl) in the B850 complex were studied by using steady-state absorption, fluorescence, fluorescence excitation, resonance Raman, and time-resolved absorption spectroscopy. The spheroidene analogues used in this study were 5',6'-dihydro-7',8'-didehydrospheroidene, 7',8'-didehydrospheroidene, and 1',2'-dihydro-3',4',7',8'-tetradehydrospheroidene. These data, taken together with results from 3,4,7,8-tetrahydrospheroidene, 3,4,5,6-tetrahydrospheroidene, 3,4-dihydrospheroidene, and spheroidene already published (Frank, H. A.; Farhoosh, R.; Aldema, M. L.; DeCoster, B.; Christensen, R. L.; Gebhard, R.; Lugtenburg, J. Photochem. Photobiol. 1993, 57, 49. Farhoosh, R.; Chynwat, V.; Gebhard, R.; Lugtenburg, J.; Frank, H. A. Photosynth. Res. 1994, 42, 157), provide a systematic series of molecules for understanding the molecular features that determine the mechanism of energy transfer from carotenoids to BChl in photosynthetic bacterial light-harvesting complexes. The data support the hypothesis that only carotenoids having 10 or less carbon-carbon double bonds transfer energy via their 21Ag (S1) states to BChl to any significant degree. Energy transfer via the 11Bu (S2) state of the carotenoid becomes more important than the S1 route as the number of conjugated carbon-carbon double bonds increases. The results also suggest that the S2 state associated with the Qx transition of the B850 BChl is the most likely acceptor state for energy transfer originating from both the 2{sup 1}A{sub g} (S{sub 1}) and 1{sup 1}B{sub u} (S{sub 2}) states of all carotenoids.},
doi = {10.1021/jp980911j},
journal = {J. Phys. Chem. B},
number = 42 ; Oct. 15, 1998,
volume = 102,
place = {United States},
year = {Thu Oct 15 00:00:00 EDT 1998},
month = {Thu Oct 15 00:00:00 EDT 1998}
}