Garrido-Barros Pablo, Romero Catherine G, Winkler Jay R, Peters Jonas C
Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States.
J Am Chem Soc. 2024 May 8;146(18):12750-12757. doi: 10.1021/jacs.4c02610. Epub 2024 Apr 26.
Interest in applying proton-coupled electron transfer (PCET) reagents in reductive electro- and photocatalysis requires strategies that mitigate the competing hydrogen evolution reaction. Photoexcitation of a PCET donor to a charge-separated state (CSS) can produce a powerful H-atom donor capable of being electrochemically recycled at a comparatively anodic potential corresponding to its ground state. However, the challenge is designing a mediator with a sufficiently long-lived excited state for bimolecular reactivity. Here, we describe a powerful ferrocene-derived photoelectrochemical PCET mediator exhibiting an unusually long-lived CSS (τ ∼ 0.9 μs). In addition to detailed photophysical studies, proof-of-concept stoichiometric and catalytic proton-coupled reductive transformations are presented, which illustrate the promise of this approach.
在还原性电催化和光催化中应用质子耦合电子转移（PCET）试剂的兴趣需要减轻竞争性析氢反应的策略。将PCET供体光激发到电荷分离态（CSS）可以产生一种强大的氢原子供体，该供体能够在与其基态相对应的相对阳极电位下进行电化学循环。然而，挑战在于设计一种具有足够长寿命激发态以实现双分子反应性的介质。在此，我们描述了一种强大的二茂铁衍生的光电化学PCET介质，其具有异常长寿命的CSS（τ ∼ 0.9 μs）。除了详细的光物理研究外，还展示了概念验证的化学计量和催化质子耦合还原转化，这说明了这种方法的前景。
