B-side Electron Transfer in Bacterial Photosynthetic Reaction Centers Revealed by a Few-Cycle Pulse Laser

Abstract

B-side electron transfer in wide-type reaction centers from Rhodobacter sphaeroides 2.4.1 was investigated by broadband real-time vibrational spectroscopy. H-B(-) was found to be generated in less than 50 fs after the excitation of 6.3 fs laser pulse, and its decay lifetime was determined to be similar to 280fs and 1.4ps, which is extremely fast compared with the one occurring in A-side. Considering the ultrafast of the generation time of H-B(-), B-B rather than P was found to be the initial electron donor to the H. Hence, the initial charge-separated state is determined to be BB+HB- state.