Photoelectron spectroscopy of large water cluster anions and related systems

大水团簇阴离子的光电子能谱及相关系统

• 批准号: 219187892
• 负责人: Professor Dr. Bernd von Issendorff
• 金额: --
• 依托单位: Arbeitsgemeinschaft Clusterphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/219187892?language=en
• 关键词: Photoelectron; spectroscopy; large; water; cluster

Although the hydrated electron has been discovered almost 50 years ago, its exact nature is still under debate. The reason lies in the complexity of the self-trapping effect, which reaches from details of the electron-water interaction to the structure of water itself. Water cluster anions are in principle ideal model systems to tackle these questions, as they allow to cover the full size range from small sizes, which are still treatable by high level calculations, to large, practically bulk-like sizes. For very small clusters (with less than 10 molecules) the agreement between theory and experiment has reached an impressively high level. This is not the case for larger clusters, though; neither the exact nature of the several structural forms of the clusters observed nor the correct extrapolation of the results to the bulk is known. On the experimental side, this is due to technical shortcomings of the existing measurements, like limited size range or lack of precise temperature control. Using a new generation cluster spectroscopy setup we plan to perform photoelectron spectroscopy on temperature controlled water cluster anions and related systems in a very broad size range. The results are expected to substantially improve the understanding of excess electrons in water clusters, and to finally clarify how these properties converge to the bulk.

尽管水合电子在近50年前就被发现了，但它的确切性质仍在争论中。原因在于自陷效应的复杂性，它从电子-水相互作用的细节到水本身的结构。原则上，水团簇阴离子是解决这些问题的理想模型系统，因为它们允许覆盖从小尺寸到大尺寸的全尺寸范围，小尺寸仍然可以通过高水平计算处理，大的尺寸几乎类似于大块尺寸。对于非常小的星团(分子少于10)，理论和实验之间的一致性已经达到了令人印象深刻的高水平。然而，对于较大的星系团来说，情况并非如此；所观察到的几种星系团结构形式的确切性质，以及对整体结果的正确推断，都是未知的。在实验方面，这是由于现有测量方法的技术缺陷，如尺寸范围有限或缺乏精确的温度控制。利用新一代团簇光谱装置，我们计划在很宽的尺寸范围内对温控水团簇阴离子及其相关体系进行光电子能谱研究。这些结果有望极大地提高对水团簇中过剩电子的理解，并最终澄清这些性质是如何会聚到整体的。