title: Picosecond absorbance difference spectra of the antenna of photosynthetic purple bacteria. The influence of exciton interactions and librations.
abstract: The influence of exciton interactions and pseudolocal librational modes on the relaxation of photo-induced absorption changes of the light-harvesting antenna of the photosynthetic purple bacterium, Rhodospirillum rubrum, was studied in the ps time domain. A hypothesis is put forward that the long-lived librational modes can occur in the circular aggregate of light-harvesting bacteriochlorophyll molecules of the core antenna. The model spectra obtained quantitatively fit the shape of the photo-induced picosecond absorbance difference spectra. The model predicts the decay of photo-induced spectra with the time constant within tens of picoseconds.
authors.affiliation: Physical Faculty, Vilnius University, Lithuania.
authors.forename: R
authors.initials: R
authors.lastname: Danielius
authors.forename: V
authors.initials: V
authors.lastname: Novoderezhkin
authors.forename: A
authors.initials: A
authors.lastname: Razjivin
mesh_terms: D020130:Bacterial Chromatophores / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D045342:Light-Harvesting Protein Complexes; D008962:Models, Theoretical; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D012247:Rhodospirillum rubrum / Q000378:metabolism*; D013055:Spectrophotometry, Infrared; D013997:Time Factors
chemical_list: D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins