Department of Chemistry, Durham University, Durham DH1 3LE, UK.
Nat Chem. 2018 Mar;10(3):341-346. doi: 10.1038/nchem.2912. Epub 2018 Jan 8.
The primary electron-attachment process in electron-driven chemistry represents one of the most fundamental chemical transformations with wide-ranging importance in science and technology. However, the mechanistic detail of the seemingly simple reaction of an electron and a neutral molecule to form an anion remains poorly understood, particularly at very low electron energies. Here, time-resolved photoelectron imaging was used to probe the electron-attachment process to a non-polar molecule using time-resolved methods. An initially populated diffuse non-valence state of the anion that is bound by correlation forces evolves coherently in ∼30 fs into a valence state of the anion. The extreme efficiency with which the correlation-bound state serves as a doorway state for low-energy electron attachment explains a number of electron-driven processes, such as anion formation in the interstellar medium and electron attachment to fullerenes.
电子驱动化学反应中的初级电子附加过程代表了最基本的化学转化之一，在科学和技术中具有广泛的重要性。然而，电子与中性分子反应形成阴离子这一看似简单的反应的机理细节仍然知之甚少，特别是在非常低的电子能量下。在这里，使用时间分辨方法通过时间分辨光电子成像来探测非极性分子的电子附加过程。阴离子最初占据的弥散非价态通过相关力在约 30fs 内相干地演化成阴离子的价态。相关束缚态作为低能电子附加的门户状态的极高效率解释了许多电子驱动过程，例如星际介质中的阴离子形成和富勒烯的电子附加。
