The Singlet Quenching of Chlorophyll b by Charge Transfer Interaction with Quinones

Abstract

There have been numerous reports on the quenching of chlorophyll a (Chl a) fluorescence by various oxidizing and reducing agents.^1–10 On the basis of the dependence of the quenching constants on the redox potentials of the quenchers, an electron transfer mechanism has been proposed although there is no experimental evidence for the radical ion pair formation. A survey of literature on chlorophyll fluorescence quenching shows that there have been no studies of singlet quenching of chlorophyll b (Chl b) so far. On the basis of singlet excited state halfwave potential values, Chl b would be expected to

Key Words:

• Fluorescence quenching
• Chlorophyll a
• Chlorophyll b
• Quinones