Dirk M. Guldi研究组取得一项新突破。他们报道了高压泵-探针实验揭示了激发态质子耦合电子转移的机理以及从阶梯转移到协同转移的转变。这一研究成果发表在2025年3月20日出版的国际学术期刊《自然-化学》上。

该研究组在高压下从钌络合物的激发态检查了PCET。在较低的缓冲剂或淬灭剂浓度下，观察到PT/ET逐步机制。随着压力的增大，PT变慢，ET变快，两步并拢。相比之下，在较高浓度的缓冲液或淬灭剂下，CPET的反应速率没有压力依赖性。这是因为电子和质子的同时转移避免了电荷的变化，从而避免了过渡态中溶剂的电致伸缩。他们的发现表明，压力可以作为一种工具来监测PCET通路上的电荷变化，帮助确定其机制。

据悉，自然和人工系统中的化学能转换和存储依赖于质子耦合电子转移（PCET）过程。协同质子-电子转移（CPET）可以提供比逐步过程(电子转移（ET)/质子转移（PT）或PT/ET）动力学优势，因此了解如何区分和调节这些过程对其相关应用很重要。

附：英文原文

Title: High-pressure pump–probe experiments reveal the mechanism of excited-state proton-coupled electron transfer and a shift from stepwise to concerted pathways

Author: Langford, Daniel, Rohr, Robin, Bauroth, Stefan, Zahl, Achim, Franke, Alicja, Ivanovi-Burmazovi, Ivana, Guldi, Dirk M.

Issue&Volume: 2025-03-20

Abstract: Chemical energy conversion and storage in natural and artificial systems rely on proton-coupled electron transfer (PCET) processes. Concerted proton-electron transfer (CPET) can provide kinetic advantages over stepwise processes (electron transfer (ET)/proton transfer (PT) or PT/ET), so understanding how to distinguish and modulate these processes is important for their associated applications. Here, we examined PCET from the excited state of a ruthenium complex under high pressures. At lower buffer or quencher concentrations, a stepwise PT/ET mechanism was observed. With increasing pressure, PT slowed and ET sped up, indicating a merging of the two steps. In contrast, CPET at higher concentrations of buffer or quencher showed no pressure dependence of the reaction rate. This is because the simultaneous transfer of electrons and protons circumvents changes in charges and, consequently, in solvent electrostriction during the transition state. Our findings demonstrate that pressure can serve as a tool to monitor charge changes along PCET pathways, aiding in the identification of its mechanisms.

DOI: 10.1038/s41557-025-01772-5

Source: https://www.nature.com/articles/s41557-025-01772-5