2-粒子-1-空穴Feshbach共振形成羟基阴离子的强证据

中文摘要 AI 辅助

本研究以2-丙醇为模型体系，通过解离电子附着过程研究羟基阴离子（OH$^-$）的形成，该体系可用于研究有机和无机分子。利用高水平的CAP-EOM-EA-CCSD计算和先进的飞行时间质谱技术，我们证明在7至11 eV电子能量范围内，OH$^-$的形成主要由双粒子-单空穴（2p-1h）Feshbach共振主导。势能曲线揭示了一个密集的阴离子态流形，这些态通过众多避免交叉相互耦合，促进了C-OH键解离过程中的非绝热布居转移。存活概率分析识别出六个长寿命共振的子集，它们能够持续足够长的时间以驱动碎裂，其中态25和态28作为主要驱动者，将附着电子引入局域的$\sigma^*(\text{C{-}OH})$反键轨道。这些理论预测与实验中观察到的在8.6 eV处显著的OH$^-$产率峰相吻合，支持了一种位点特异性碎裂机制，该机制可推广到更广泛的分子类别。

英文摘要

This study investigates the formation of the hydroxyl anion (OH$^-$) via dissociative electron attachment in 2-propanol as a model system for studying both organic and inorganic molecules. Using high-level CAP-EOM-EA-CCSD calculations and advanced ToF mass spectrometry, we demonstrate that OH$^-$ formation at electron energies between 7 and 11 eV is dominated by two-particle-one-hole (2p-1h) Feshbach resonances. The potential-energy curves reveal a dense manifold of anionic states coupled through numerous avoided crossings, facilitating nonadiabatic population transfer during C-OH bond dissociation. Survival-probability analysis identifies a subset of six long-lived resonances that persist long enough to drive fragmentation, with states 25 and 28 acting as primary drivers by funneling the attached electron into the localized $σ^*(\mathrm{C{-}OH})$ antibonding orbital. These theoretical predictions are confirmed by experimental observations of a prominent OH$^-$ yield peaking at 8.6 eV, supporting a site-specific fragmentation mechanism that generalizes to the broader class of molecules.

发表机构

• Indian Institute of Science Education and Research Kolkata（印度科学教育研究学院加尔各答分校）
• Ashoka University（阿肖卡大学）
• Institute of Physical Chemistry, Polish Academy of Sciences（波兰科学院物理化学研究所）
• University of Kassel（卡塞尔大学）
• Center for Atomic, Molecular and Optical Sciences and Technologies, Joint initiative of IIT Tirupati and IISER Tirupati（原子、分子和光学科学与技术中心（泰米尔纳德邦理工学院与泰米尔纳德邦科学教育研究学院联合倡议））

机构由 AI 辅助整理，请以论文原文为准。

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10 pages, 8 figures