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Updated: Jun 23, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
The absolute quantum efficiency of bacteriochlorophyll photooxidation in reaction centres of Rhodopseudomonas
1Section of Genetics, Development and Physiology, Plant Science Building, Cornell University, Ithaca, NY 14850, USA.
Abstract:
The widely assumed correspondence between fluorescence and photochemistry in photosynthetic systems has recently been challenged by observations on the triplet state of bacteriochlorophyll in reaction centres of Rhodopseudomonas spheroides. In order to check this assumption we have conducted a precise determination of the quantum efficiency of bacteriochlorophyll photooxidation in reaction centres at room temperature. We find a quantum efficiency of 1.02 +/- 0.04 in contrast to a value of about 0.7 predicted from the variations in fluorescence yield.
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