Proton-coupled electron transfer across benzimidazole bridges in bioinspired proton wires.
Proton-coupled electron transfer across benzimidazole bridges in bioinspired proton wires.
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DOI：
10.1039/c9sc06010c
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发表时间：
2020-03-20
期刊：
影响因子：
8.4
通讯作者：
Moore AL
中科院分区：
文献类型：
--
作者：
Odella E;Mora SJ;Wadsworth BL;Goings JJ;Gervaldo MA;Sereno LE;Groy TL;Gust D;Moore TA;Moore GF;Hammes-Schiffer S;Moore AL
设计用于控制人工光合系统中质子和电子运动的分子平台对于高效催化和太阳能转换至关重要。在反应期间质子和电子两者的转移被称为质子耦合电子转移（PCET），并且被自然界以无数方式用于为氧化还原反应和氧化还原平衡提供低过电位途径，以及产生生物能质子电流。在此，我们描述了一系列的生物启发苯并咪唑-苯酚（BIP）衍生物和一系列的二苯并咪唑-苯酚（BI 2 P）类似物的理论和电化学研究，每个系列具有相同的一组终端质子接受（TPA）基团。TPA组跨越超过6个pKa单位。这些化合物旨在探索桥连苯并咪唑在单电子氧化过程中的作用，该过程与分子内质子跨两个（BIP系列）或三个（BI 2 P系列）酸/碱位点的转移偶联。这些分子构建体的特征在于通过苯并咪唑基桥连接到TPA基团的电化学活性苯酚，其与苯酚和TPA基团一起形成支持Grotthuss型氢键网络的共价框架。红外光谱电化学表明，在氧化的苯酚，质子易位通过这个定义明确的氢键网络的TPA组。实验数据显示，苯并咪唑桥在PCET过程中是非无辜的参与者，因为每个苯并咪唑单元的加入使苯氧基自由基/苯酚对的氧化还原电位降低60 mV，而不管TPA基团的性质如何。使用一系列假设的热力学步骤，密度泛函理论计算正确预测的苯氧基自由基/苯酚对的氧化还原电位的最终质子化的物种的性质的依赖性，并提供洞察二苯并咪唑单元的热力学作用在PCET过程中。这些信息对于开发具有这些部分的分子“干质子线”至关重要，这些部分可以通过Grotthuss型机制长距离传输质子，而无需水分子的干预。实验和理论方法表征电化学驱动的质子耦合的电子转移过程中的生物启发的构造涉及多个质子易位在格罗特胡斯型质子线的热力学。
Designing molecular platforms for controlling proton and electron movement in artificial photosynthetic systems is crucial to efficient catalysis and solar energy conversion. The transfer of both protons and electrons during a reaction is known as proton-coupled electron transfer (PCET) and is used by nature in myriad ways to provide low overpotential pathways for redox reactions and redox leveling, as well as to generate bioenergetic proton currents. Herein, we describe theoretical and electrochemical studies of a series of bioinspired benzimidazole-phenol (BIP) derivatives and a series of dibenzimidazole-phenol (BI2P) analogs with each series bearing the same set of terminal proton-accepting (TPA) groups. The set of TPAs spans more than 6 pKa units. These compounds have been designed to explore the role of the bridging benzimidazole(s) in a one-electron oxidation process coupled to intramolecular proton translocation across either two (the BIP series) or three (the BI2P series) acid/base sites. These molecular constructs feature an electrochemically active phenol connected to the TPA group through a benzimidazole-based bridge, which together with the phenol and TPA group form a covalent framework supporting a Grotthuss-type hydrogen-bonded network. Infrared spectroelectrochemistry demonstrates that upon oxidation of the phenol, protons translocate across this well-defined hydrogen-bonded network to a TPA group. The experimental data show the benzimidazole bridges are non-innocent participants in the PCET process in that the addition of each benzimidazole unit lowers the redox potential of the phenoxyl radical/phenol couple by 60 mV, regardless of the nature of the TPA group. Using a series of hypothetical thermodynamic steps, density functional theory calculations correctly predicted the dependence of the redox potential of the phenoxyl radical/phenol couple on the nature of the final protonated species and provided insight into the thermodynamic role of dibenzimidazole units in the PCET process. This information is crucial for developing molecular “dry proton wires” with these moieties, which can transfer protons via a Grotthuss-type mechanism over long distances without the intervention of water molecules. Experimental and theoretical methods characterize the thermodynamics of electrochemically driven proton-coupled electron transfer processes in bioinspired constructs involving multiple proton translocations over Grotthus-type proton wires.
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DOI：
10.1016/j.saa.2016.03.021
发表时间：
2016-06-15
影响因子：
4.4
作者：
Cao, Chao-Tun;Bi, Yakun;Cao, Chenzhong
通讯作者：
Cao, Chenzhong
影响因子：
15
作者：
Odella, Emmanuel;Wadsworth, Brian L.;Moore, Ana L.
通讯作者：
Moore, Ana L.
影响因子：
2.9
作者：
Forés, M;Duran, M;Luque, FJ
通讯作者：
Luque, FJ
DOI：
10.1073/pnas.0708967105
发表时间：
2008-06-17
影响因子：
11.1
作者：
Markle, Todd F.;Rhile, Ian J.;Mayer, James M.
通讯作者：
Mayer, James M.
影响因子：
4.8
作者：
Mathes, Tilo;van Stokkum, Ivo H. M.;Kennis, John T. M.
通讯作者：
Kennis, John T. M.