Nonexponential kinetics of primary charge separation in purple bacterial reaction centre

摘要: Nonexponential kinetics of the primary charge separation in photosynthetic purple bacterial reaction centers of Rb. sphaeroides has been simulated. The fluctuations of the free energy gap between the states of the excited electron donor and of the oxidized electron donor and the reduced electron acceptor have been modelled by diffusion in the parabolic potential, with the sink described by the Marcus charge separation rate formula. The parameters required to fit the experimental biexponential charge separation kinetics have been found, and the interpretation of kinetic components has been proposed. The kinetic component with a shorter lifetime (2.9 ps) has been determined to reflect the reorganization of free energy gap distribution, while the component with a longer lifetime (11.7 ps) has been attributed to the actual primary charge separation. (Author)