The electronic characteristics and rapid dynamics associated with bacteriochlorophyll dimers in photosynthetic systems are investigated using novel ultrafast anisotropy techniques. The excitonic structure of isolated subunits (B820) from the core (LH-1) light harvesting complex of Rs. Rubrum and the reassociated complex (B873) is revealed in coherent anisotropy responses following impulsive excitation. For B820, the oscillatory anisotropy responses indicate excitonic splitting frequencies ranging from 370 cm$+$MIN@1$/ to 490 cm$+$MIN@1$/ indicating significant inhomogeneity in the excitonic spectrum. The complete set of wavelength dependent anisotropy result is analyzed to reveal the sources of inhomogeneity for B820; correlated distributions of dimer energetic parameters are necessary to reproduce the results. The coherent response of reassociated B873 complexes exhibit multiple frequencies, revealing the extended excitonic structure of the aggregates. In other experiments, the electronic properties of the photosynthetic reaction center and the rapid electronic dynamics prior to charge separation are investigated by both 'two color' anisotropy. A variety of excitation and detection conditions provide the first room temperature characterization of the excitonic structure of the special pair, and a detailed description of rapid energy transfer to and within the special pair. The results presented here stress the importance of delocalized excitation in both the light harvesting antenna complexes and the photosynthetic reaction center.
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机译：采用新型超快各向异性技术研究了与光合系统中的光合系统中的菌血基氯基二聚体相关的电子特性和快速动力学。来自核心（LH-1）的核（LH-1）光收获复合物的孤立亚基（B820）的兴奋结构。在冲动激发后，在相干的各向异性反应中揭示了rubrum和Realsociated复合物（B873）。对于B820，振荡的各向异性响应表示激发器分裂频率从370厘米$ + $ MIN @ 1 $ /至490厘米$ + $ min @ 1 $ /表示激发频谱中的显着不均匀性。分析了完整的波长依赖性各向异性结果，以揭示B820的不均匀性源;有关二聚体能量参数的相关分布是再现结果的必要条件。重新分配的B873配合物的相干响应表现出多种频率，揭示了聚集体的延伸激发器结构。在其他实验中，通过“两种颜色”各向异性研究了光合反应中心和在电荷分离前的快速电子动力学的电子特性。各种激励和检测条件提供了特殊对的激发结构的第一室温表征，以及对特殊对中的快速能量转移的详细描述。这里提出的结果强调了在光收集天线复合物和光合反应中心的光学化激发中的重要性。
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