液态水中的分子间库伦比衰变与质子转移和非adiabatic放松相竞争
Pengju Zhang1,2, Joel Trester3, Jakub Dubský4
1Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China. pengju.zhang@iphy.ac.cn.
Nature communications
|July 22, 2025
概括
在水中,分子间库伦比分解 (ICD) 的效率不如以前想象的那样高. 核运动,特别是质子转移,显著影响ICD效率,在重水 (D2O) 中观察到更高的效率.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 辐射化学 辐射化学
背景情况:
- 了解水系统中的辐射损伤至关重要,但仍然有限.
- 在水的内部价值电离后发生的分子间库伦比衰变 (ICD) 是破坏低能电子的潜在来源.
- 液态水中ICD的精确效率及其影响因素尚未得到充分确立.
研究的目的:
- 通过实验确定液态水 (H2O) 和重水 (D2O) 中分子间库伦比衰变 (ICD) 的效率.
- 为了研究竞争过程的作用,如质子转移和非adiabatic放松在影响ICD效率.
- 开发一个理论模型,准确地复制观察到的ICD效率.
主要方法:
- 在液态H2O和D2O上使用高波生成光源进行了电子电子巧合测量.
- 来自2a1外的光电子与ICD电子的巧合被检测到.
- 理论分析使用了ab initio计算和一个包含溶剂效应的多尺度随机模型.
主要成果:
- 发现ICD效率 (γ) 在液态H2O和D2O中均低于单位.
- ICD效率的比率被确定为γ ((H2O) /γ ((D2O) = 0.86 ± 0.03.
- Ab initio计算表明,质子转移和非adiabatic放松与ICD过程竞争并可以灭它.
结论:
- 在液态水中ICD的效率受到核运动的显著影响,包括质子转移和非adiabatic转换.
- 与H2O相比,D2O中的更高的ICD效率归因于更慢的质子转移和更重同位素中的非adiabatic转换.
- 这些发现促进了对水性环境中辐射损伤机制的理解.
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