TY - JOUR
T1 - High-order fluorescence and exciton interaction in photosynthetic bacteria
AU - Kung, Mayfair Chu
AU - Devault, Don
N1 - Funding Information:
The authors wish to thank Dr. P.L. Dutton and his coworkers for the samples of R. sphaeroides and some of the chromatophores. A number of people, among whom may be mentioned M. Gouterman, D. Mauzerall, W.W. Parson, P.A. Loach, Govindjee, K.J. Kaufmann, C.E. Swenberg, and R.M. Hochstrasser have contributed helpful discussions. Mr. D. Henderson helped with the apparatus. We also thank Dr. William Parson for sending us several of his manuscripts before publication. Financial support came from the National Science Foundation (grants PCM76-15724 and PCM76-23744).
PY - 1978/2/9
Y1 - 1978/2/9
N2 - We have observed fluorescence at visible wavelengths from chromatophores of photosynthetic bacteria excited with infrared radiation which we attribute to bacteriochlorophyll of the antenna system. The fluorescence is prompt (no delay greater than 5 ns). Its spectrum shows peaks at 445, 530 (broad) and 600 nm when excited with either 694 or 868 nm. Quantum yield is of the order of 10-9. The dependence on intensity indicates generation by mainly third-order processes which could involve triplet states in combination with excited singlets. Second-order single-singlet fusion could also contribute. The high-order fluorescence can also be explained as arising from absorption of a second photon by singlet excited states.
AB - We have observed fluorescence at visible wavelengths from chromatophores of photosynthetic bacteria excited with infrared radiation which we attribute to bacteriochlorophyll of the antenna system. The fluorescence is prompt (no delay greater than 5 ns). Its spectrum shows peaks at 445, 530 (broad) and 600 nm when excited with either 694 or 868 nm. Quantum yield is of the order of 10-9. The dependence on intensity indicates generation by mainly third-order processes which could involve triplet states in combination with excited singlets. Second-order single-singlet fusion could also contribute. The high-order fluorescence can also be explained as arising from absorption of a second photon by singlet excited states.
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U2 - 10.1016/0005-2728(78)90028-2
DO - 10.1016/0005-2728(78)90028-2
M3 - Article
C2 - 304360
AN - SCOPUS:0018263810
VL - 501
SP - 217
EP - 231
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 2
ER -