瑞士苏黎世联邦理工学院Ruth Signorell团队报道了光激发的溶剂化介电子—低能电子的有效来源。相关研究成果发表在2023年5月25日出版的《科学》。

溶解在液氨或水介质中的低能电子是强大的还原剂，可以促进具有挑战性的还原反应，但也会对生物组织造成辐射损伤。关于潜在的机制过程的知识仍然不完整，特别是关于电子转移步骤的细节和能量学。

该文中，研究人员展示了如何利用金属氨团簇的紫外线（UV）光激发原位产生可调谐的低能电子。具体而言，将紫外光诱导的自旋配对溶剂化介电电子的产生及其随后通过非常规电子转移介导的衰变的弛豫确定为一种高效、低能量的电子源。该过程稳健而简单，有望提高人们对辐射损伤的理解，并促进溶剂化电子还原反应的机理研究。

附：英文原文

Title: Solvated dielectrons from optical excitation: An effective source of low-energy electrons

Author: Sebastian Hartweg, Jonathan Barnes, Bruce L. Yoder, Gustavo A. Garcia, Laurent Nahon, Evangelos Miliordos, Ruth Signorell

Issue&Volume: 2023-05-25

Abstract: Low-energy electrons dissolved in liquid ammonia or aqueous media are powerful reducing agents that promote challenging reduction reactions but can also cause radiation damage to biological tissue. Knowledge of the underlying mechanistic processes remains incomplete, particularly with respect to the details and energetics of the electron transfer steps. In this work, we show how ultraviolet (UV) photoexcitation of metal-ammonia clusters could be used to generate tunable low-energy electrons in situ. Specifically, we identified UV light–induced generation of spin-paired solvated dielectrons and their subsequent relaxation by an unconventional electron transfer–mediated decay as an efficient, low-energy electron source. The process is robust and straightforward to induce with the prospect of improving our understanding of radiation damage and fostering mechanistic studies of solvated electron reduction reactions.

DOI: adh0184

Source: https://www.science.org/doi/10.1126/science.adh0184