On the Role of the Special Pair in Photosystems as a Charge Transfer Rectifier
On the Role of the Special Pair in Photosystems as a Charge Transfer Rectifier
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DOI：
10.1021/acs.jpcb.9b11431
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发表时间：
2020-03-12
影响因子：
3.3
通讯作者：
Dunietz, Barry D.
中科院分区：
文献类型：
--
作者：
Aksu, Huseyin;Schubert, Alexander;Dunietz, Barry D.
这种特殊的对，在细菌反应中心的核心发现的细菌叶绿素a（BChl）二聚体，已知在光系统的功能中发挥关键作用，作为光合作用过程的前体。本文分析了特殊电子对的固有亲和势，对电子对内的光致电荷转移进行了校正。特别是，我们表明，分子环境影响的核几何形状，导致两个可能的intrapair CT过程之间的对称性破缺。为此，我们研究的intrapair CT和分子的几何形状相对于由分子环境提供的有效介电常数的关系。我们确定的特殊对结构特征，打破了两个分子之间的对称性，导致CT整流。激发态能量，振子强度，和电子耦合值通过依赖于时间的密度泛函理论，采用最近开发的框架的基础上筛选范围分离的混合功能内的极化连续模型（SRSH-PCM）。我们分析的整流能力的特殊对计算的CT率使用基于第一性原理的费米黄金法则的方法。
The special pair, a bacteriochlorophyll a (BChl) dimer found at the core of bacterial reaction centers, is known to play a key role in the functionality of photosystems as a precursor to the photosynthesis process. In this paper, we analyze the inherent affinity of the special pair to rectify the intrapair photo-induced charge transfer (CT). In particular, we show that the molecular environment affects the nuclear geometry, resulting in symmetry breaking between the two possible intrapair CT processes. To this end, we study the relationships of the intrapair CT and the molecular geometry with respect to the effective dielectric constant provided by the molecular environment. We identify the special pair structural feature that breaks the symmetry between the two molecules, leading to CT rectification. Excited state energies, oscillator strengths, and electronic coupling values are obtained via time-dependent density functional theory, employing a recently developed framework based on a screened range-separated hybrid functional within a polarizable continuum model (SRSH-PCM). We analyze the rectification capability of the special pair by calculating the CT rates using a first-principles-based Fermi's golden rule approach.