Institute of Chemical Physics, Vilnius University , Sauletekio al 9-III, 10222 Vilnius, Lithuania.
Department of Chemistry and Department of Physics, Kansas State University , 213 CBC Building, Manhattan, Kansas 66506-0401, United States.
J Phys Chem B. 2018 Feb 1;122(4):1348-1366. doi: 10.1021/acs.jpcb.7b08905. Epub 2018 Jan 17.
Spectroscopically relevant properties in photosynthetic reaction centers change during charge separation. In this paper, we focus on incorporation of the complete set of environmental fluctuations in the modeling of the nonlinear spectra of molecular aggregates. The model is applied in simulations of two-dimensional electronic spectra of a photosynthetic reaction center at low temperature (5 K), where spectral lines are narrow, such that more features can be resolved. We show that vertical cross sections of the simulated two-dimensional spectra (with all populations in the lowest excited state) reveal transient hole-burned spectra excited resonantly within the B band in agreement with experiment, thus providing new insight into environmental fluctuation parameters of Rhodobacter sphaeroides at low temperatures. Correlated fluctuations of molecular parameters are found to be necessary to describe charge separated configurations of molecular excited states.
在电荷分离过程中，光合作用反应中心的光谱相关性质会发生变化。在本文中，我们专注于在分子聚集体的非线性光谱建模中纳入完整的环境波动集。该模型应用于光合作用反应中心在低温（5 K）下二维电子光谱的模拟，在低温下光谱线很窄，可以分辨出更多的特征。我们表明，模拟二维光谱的垂直截面（所有处于最低激发态的种群）揭示了在 B 带内共振激发的瞬态空穴烧蚀光谱，与实验结果一致，从而为低温下球形红杆菌的环境波动参数提供了新的见解。发现分子参数的相关波动对于描述分子激发态的电荷分离构型是必要的。
