Abstract

The photosynthetic reaction center of Rb. sphaeroides is investigated by unique pump-probe anisotropy methods using 13 fs optical pulses tunable throughout the near IR absorption band. The time and wavelength resolved pump probe anisotropy transients yield detailed experimental descriptions of the energy levels, Py+ and Py- of the excitonically coupled special pair (P), and dynamics prior to charge separation, particularly energy transfer from the accessory bacteriochlorophylla's (B) to the special pair (P).