Experimental Physics IV and Bayreuth Institute for Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany.
J Phys Chem B. 2012 Sep 13;116(36):11017-23. doi: 10.1021/jp3040456. Epub 2012 Sep 4.
Evidence for the formation of self-trapped exciton states in photosynthetic antenna complexes is provided by comparing single-molecule fluorescence-excitation and emission spectra that have been recorded from the same individual LH2 complex from Rhodopseudomonas acidophila . While the excitation spectra showed the signatures for the B800 and B850 bands as observed previously, two distinctively different types of emission spectra were found. One group of antenna complexes shows spectra with a relatively narrow spectral profile with a clear signature of a zero-phonon line, whereas the other group of complexes displays spectra that consist only of a broad featureless band. Analysis of these data reveals clear correlations between the spectral position of the emission, the width of the spectral profile, and the associated electron-phonon coupling strength.
为光合天线复合物中自陷激子态的形成提供了证据，方法是比较从嗜酸红假单胞菌的同一个 LH2 复合物中记录的单分子荧光激发和发射光谱。虽然激发光谱显示了之前观察到的 B800 和 B850 带的特征，但发现了两种截然不同的发射光谱类型。一组天线复合物显示出具有相对较窄光谱轮廓的光谱，并且具有零声子线的清晰特征，而另一组复合物显示的光谱仅由一个宽的无特征带组成。对这些数据的分析揭示了发射光谱的位置、光谱轮廓的宽度以及相关的电子-声子耦合强度之间的明显相关性。
