揭开水合氢离子和氢氧根相互中和的非绝热途径，这一成果由斯德哥尔摩大学Daniel Strasser研究组经过不懈努力而取得。2025年3月25日出版的《自然-化学》杂志发表了这一最新研究成果。

对分离的D₃O⁺和OD，揭示了OD自由基形成的非绝热途径。两种相互竞争的途径导致不同的D₂O+OD+D和2OD+D₂产物通道，而质子转移机制由于动力学同位素效应基本上被抑制。三体动量相关性分析表明，D₂O+OD+D通道由电子在~4短距离转移形成。形成中间不稳定的中性D₃O基态，而2OD+D2产物是在距离约10Å处通过中性D₃O的激发态进行电子转移后获得的。

据了解，水合氢离子和氢氧根离子的相互中和是一种基本的化学反应。然而，关于其本质非绝热机理的直接实验证据非常有限。化学教科书将散装水中相互中和的产物描述为两个水分子；然而，这一反应被认为是最近报道的水微滴表面OH自由基自发形成的可能机制。

附：英文原文

Title: Unravelling non-adiabatic pathways in the mutual neutralization of hydronium and hydroxide

Author: Bogot, Alon, Poline, Mathias, Ji, MingChao, Dochain, Arnaud, Rosn, Stefan, Zettergren, Henning, Schmidt, Henning T., Thomas, Richard D., Strasser, Daniel

Issue&Volume: 2025-03-25

Abstract: The mutual neutralization of hydronium and hydroxide ions is a fundamental chemical reaction. Yet, there is very limited direct experimental evidence about its intrinsically non-adiabatic mechanism. Chemistry textbooks describe the products of mutual neutralization in bulk water as two water molecules; however, this reaction has been suggested as a possible mechanism for the recently reported spontaneous formation of OH radicals at the surface of water microdroplets. Here, following three-dimensional-imaging of the coincident neutral products of reactions of isolated D3O+ and OD, we can reveal the non-adiabatic pathways for OD radical formation. Two competing pathways lead to distinct D2O+OD+D and 2OD+D2 product channels, while the proton-transfer mechanism is substantially suppressed due to a kinetic isotope effect. Analysis of the three-body momentum correlations revealed that the D2O+OD+D channel is formed by electron transfer at a short distance of ~4 with the formation of the intermediate unstable neutral D3O ground state, while 2OD+D2 products are obtained following electron transfer at a distance of ~10 via an excited state of the neutral D3O.

DOI: 10.1038/s41557-025-01771-6

Source: https://www.nature.com/articles/s41557-025-01771-6