Ultrafast energy transfer in LHC-II revealed by three-pulse photon echo peak shift measurements
Ultrafast energy transfer in LHC-II revealed by three-pulse photon echo peak shift measurements
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DOI：
10.1021/jp9915578
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发表时间：
2000-04-06
影响因子：
3.3
通讯作者：
Fleming, GR
中科院分区：
文献类型：
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作者：
Agarwal, R;Krueger, BP;Fleming, GR
我们报告了绿藻莱茵衣藻的光捕获复合体 II (LHC-II) 的三脉冲光子回波峰移 (3PEPS) 测量结果。实验在两种不同的激发波长（670 和 650 nm）下进行。分别对应于 Chi-a 和 Chl-b 激发，使用新理论分析 3PEPS 数据，该理论结合了能量转移对三阶响应函数的影响。我们的理论模型将能量转移动力学与电子跃迁与蛋白质环境耦合产生的溶剂化动力学分开。我们认为蛋白质波动可以通过亚 100 fs 时间尺度上的超快溶剂化和长时间相关性（静态无序）来描述。 670 nm 峰移的衰减揭示了 Chl-rr 分子的光谱平衡时间尺度，范围从 300 fs 到 6 ps，并且与其他实验非常吻合。 650 nm 处的 3PEPS 数据（叶绿素-b 激发）揭示了叶绿素-b 到叶绿素-b 的快速能量转移（
We report the results of three-pulse photon echo peak shift (3PEPS) measurements on the light-harvesting complex II (LHC-II) of the green algae Chlamydomonas reinhardtii. Experiments were performed at two different excitation wavelengths, 670 and 650 nm. corresponding to Chi-a and Chl-b excitation, respectively, The 3PEPS data are analyzed using a new theory that incorporates the effect of energy transfer on third-order response functions. Our theoretical model separates energy transfer dynamics from the solvation dynamics arising from coupling of the electronic transitions to the protein environment. We suggest that the protein fluctuations can be described by an ultrafast solvation on a sub-100 fs time scale and a long time correlation (static disorder). Decay of the 670 nm peak shift reveals spectral equilibration time scales for Chl-rr molecules that range from 300 fs to 6 ps and agree well with other experiments. 3PEPS data at 650 nm (Chl-b excitation) reveal rapid Chl-b to Chl-b energy transfer (