Electron-Induced Synthesis of Formamide in Condensed Mixtures of Carbon Monoxide and Ammonia
Electron-Induced Synthesis of Formamide in Condensed Mixtures of Carbon Monoxide and Ammonia
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DOI：
10.1021/acsearthspacechem.6b00011
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发表时间：
2017-03-01
影响因子：
3.4
通讯作者：
Swiderek, Petra
中科院分区：
文献类型：
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作者：
Bredehoeft, Jan H.;Boehler, Esther;Swiderek, Petra
在 30-35 K 的低温下，研究了在氨和一氧化碳的电子照射下，益生元相关分子甲酰胺的形成。使用辐射后热解吸光谱来研究反应的能量依赖性。观察到以类似于 9 eV 为中心的谐振过程以及高于类似于 12 eV 的阈值类型的产率增加。在不存在尿素和乙二酰胺等特定副产物的基础上，并在量子化学计算的支持下，提出了与甲酰胺生产的两种观察到的能量状态相关的反应机制。低于电离阈值，电子附着在氨上以及随后自由基阴离子的解离触发反应序列。在较高能量下，电子碰撞电离以及形成的自由基阳离子与中性分子的加成最终导致甲酰胺的形成。
The formation of the prebiotically relevant molecule formamide under electron exposure of ammonia and carbon monoxide was studied at cryogenic temperatures of 30-35 K. Postirradiation thermal desorption spectroscopy was used to study the energy dependence of the reaction. A resonant process centered around similar to 9 eV and a threshold type increase of the yield above similar to 12 eV were observed. On the basis of the absence of particular side products such as urea and ethanediamide and supported by quantum chemical calculations, reaction mechanisms related to the two observed energy regimes of formamide production are proposed. Below the ionization threshold, electron attachment to ammonia and the subsequent dissociation of the radical anion trigger the reaction sequence. At higher energies, electron impact ionization and addition of the formed radical cation to a neutral molecule ultimately lead to the formation of formamide.