Photoelectron Spectra of Hot Polyatomic Ions: A Statistical Treatment of Phenide
Photoelectron Spectra of Hot Polyatomic Ions: A Statistical Treatment of Phenide
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热多原子离子的光电子能谱：Phenide 的统计处理
DOI：
10.1021/acs.jpca.2c07361
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Sanov, Andrei
中科院分区：
文献类型：
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作者：
Ru, Beverly;Sanov, Andrei
许多不同的振动状态导致热多原子阴离子的拥挤光电子能谱。这通常使得完整的 Franck-Condon (FC) 分析既不切实际又不必要。尽管通常将 FC 计算限制为 FC 活性模式的子集，但这种有限方法仅严格适用于基态（冷）阴离子。在高温下，所有振动模式都参与热激发，并且 FC 和热活动交织在一起。我们报告了在 355 nm (3.49 eV)、532 nm (2.33 eV) 和 611 nm (2.03 eV) 处获得的~700 K 苯醚 (C6H5–) 的光电子能谱，并描述了几个有助于解释和分析结果的实用模型。其中包括主动模式模型、主动模式+暗浴模型和主动模式+明浴模型，最后是节能模型。该模型将有限（因此可行）FC 计算的结果与统计分析相结合，并提供从宽而拥挤的光电子能谱确定离子温度的有效方法。所描述的功能可应用于热等离子体、离子的碰撞激发或冷却以及簇离子的蒸发冷却。
Many distinct vibrational states contribute to the congested photoelectron spectra of hot polyatomic anions. This often makes the complete Franck–Condon (FC) analysis both impractical and unnecessary. Although it is common to limit the FC calculations to a subset of the FC-active modes, such a limited approach is strictly applicable to the ground-state (cold) anions only. At high temperatures, all vibrational modes participate in thermal excitation, and the FC and thermal activities become intertwined. We report the photoelectron spectra of ∼700 K phenide (C6H5–) obtained at 355 nm (3.49 eV), 532 nm (2.33 eV), and 611 nm (2.03 eV) and describe several practical models that help interpret and analyze the results. Among them are the active-modes model, the active modes + dark bath and the active modes + bright bath models, and, finally, the energy-conservation model. The models combine the results of limited (and, therefore, feasible) FC calculations with statistical analysis and provide efficient means of determining the ion temperature from the broad and congested photoelectron spectra. The described capability can be applied to hot plasmas, the collisional excitation or cooling of ions, and evaporative cooling in cluster ions.