title: Effect of the donor-bridge energy gap on the electron-transfer mechanism in donor-bridge-acceptor systems.
abstract: The effect of the energy gap between donor and bridge states in the electron transfer of a double mutant photosynthetic purple bacterial reaction center is thoroughly investigated using a recently introduced modified on-the-fly filtered propagator important path integral formalism. By decomposition of the reduced density matrix of a system coupled to a dissipative environment, partial contributions of incoherent hopping, coherent superexchange, and partially coherent hopping transport to the overall electron or charge transfer are evaluated. Within the tight-binding donor-bridge-acceptor model, the three mechanisms coexist for a wide range of donor-bridge energy gap values, and the governing mechanism changes from incoherent hopping to partially coherent hopping and eventually to coherent superexchange as the donor-bridge energy gap becomes large.
authors.affiliation: Department of Chemistry, Yonsei University, 134 Sinchondong Seodaemungu, Seoul 120-749, South Korea. esim@yonsei.ac.kr
authors.forename: Eunji
authors.initials: E
authors.lastname: Sim
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D004579:Electron Transport; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D045322:Photosynthetic Reaction Center Complex Proteins