Institute of physics conference series issue:126 pages:609-612
The picosecond fluorescence kinetics of closed (quinone acceptor Q(A) reduced) reaction centers isolated from the phototrophic bacterium C. aurantiacus shows time constants of almost-equal-to 20 ps and almost-equal-to 300 ps (amplitude ratio almost-equal-to 1:1). They are nearly independent of temperature (7K to 80K). Assuming a three-state kinetic model, two assignments of the kinetics to the electron transfer processes seem to be possible. One model includes a reversible electron transfer between P* and H(M), the pheophytin(s) in the M-branch. The other model involves the formation of a monomeric bacteriochlorophyll anion.