Detailed studies of the subpicosecond kinetics in the primary electron transfer of reaction centers of Rhodopseudomonas viridis

The primary, light-induced charge separation in reaction centers of
Rhodopseudomonas viridis is investigated with femtosecond time
resolution. The absorption changes after direct excitation of the
primary donor P at 955 nm are investigated in the time range from
100 fs to 600 ps. The experimental data, taken at various probing
wavelengths, reveal one subpicosecond and two picosecond time
constants: 0.65 ± 0.2 ps, 3.5 ± 0.4 ps, and 200 ± 20 ps. The
previously undetected 0.65 ps kinetics can be observed clearly in
the spectral range of the Qx and Qy transitions of the monomeric
bacteriochlorophylls. The experimental data support the idea that
the accessory bacteriochlorophyll B A participates in the
electron-transfer process. References