Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
J Phys Chem B. 2013 Sep 26;117(38):11349-62. doi: 10.1021/jp403028x. Epub 2013 Jul 18.
Excited state dynamics in LH2 complexes of two purple bacterial species were studied by broad-band two-dimensional electronic spectroscopy. The optical response was measured in the 500-600 nm spectral region on the 0-400 fs time scale. Global target analysis of two-dimensional (2D) transient spectra revealed the main energy transfer pathways between carotenoid S2, 1Bu(-) and S1 states and bacteriochlorophyll Qx state. Global analysis ascertained the evolutionary and vibration-associated spectra, which also indicated the presence of a higher-lying vibrational level in the carotenoid S1 state. The estimation of the spectral overlap between the 1Bu(-) state and the Qx state indicated a significant contribution of the 1Bu(-) state to the overall S2-to-Qx excitation energy transfer.
通过宽带二维电子光谱研究了两种紫色细菌 LH2 复合物的激发态动力学。在 0-400 fs 的时间尺度上，在 500-600nm 的光谱区域测量了光响应。二维（2D）瞬态光谱的全局目标分析揭示了类胡萝卜素 S2、1Bu(-) 和 S1 态与细菌叶绿素 Qx 态之间的主要能量转移途径。全局分析确定了进化和振动相关的光谱，这也表明类胡萝卜素 S1 态中存在更高的振动能级。对 1Bu(-)态和 Qx 态之间的光谱重叠的估计表明，1Bu(-)态对 S2 到 Qx 激发能量转移的整体贡献显著。
