一个系统的机制性调查OH基和CH3OH在冰上的反应
W M C Sameera1,2, Avon P Jayaweera2, Atsuki Ishibashi1
1Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido 060-0819, Japan. wmcsameera@lowtem.hokudai.ac.jp.
Faraday discussions
|June 19, 2023
概括
这项研究研究了甲醇 (CH3OH) 和基 (OH) 在冰上的反应,显示CH2OH基结最强,其次是甲醇分子和CH3O基结. 这些发现对于计算天体化学至关重要.
科学领域:
- 天体化学是天体化学.
- 化学动力学 化学动力学
- 表面科学是一门学科.
背景情况:
- 在星际冰化学中,甲醇 (CH3OH) 和基 (OH) 之间的反应是重要的.
- 了解冰面上的吸附和反应机制对于天体化学至关重要.
研究的目的:
- 系统地研究CH3OH + OH反应在六角水冰 (Ih) 和无形固体水 (ASW) 上的反应机制和结合能.
- 为了确定CH3OH,CH2OH和CH3O在冰面上的相对结合强度.
- 为天体化学界提供可靠的计算数据.
主要方法:
- 使用ONIOM ((ωB97X-D/Def2-TZVP:AMOEBA09) 计算来确定冰上分子和基的结合能.
- 利用多组件人造力诱导反应 (MC-AFIR) 方法系统地探索反应路径.
- 使用 ωB97X-D/Def2-TZVP 理论水平计算反应障碍.
主要成果:
- 计算的结合能量显示了冰上吸附强度的顺序:CH2OH基 > CH3OH分子 > CH3O基.
- 确定了冰上CH3OH + OH的两个主要反应途径,导致CH2OH和CH3O基.
- 对于CH2OH基质形成的反应障碍范围在0.03-0.11 eV之间,而对于CH3O基质形成的反应障碍范围在0.03-0.44 eV之间.
- 结合部位和反应部位显著影响计算的结合能量和反应障碍.
结论:
- 在冰面上,CH2OH和CH3O两种基质形成途径都可能发生.
- 计算的结合能和反应障碍对于精制天体化学模型非常有价值.
- 该研究强调了在计算天体化学中考虑特定的结合和反应场所的重要性.
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