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。原因在于自俘获效应的复杂性，从电子-水相互作用的细节到水本身的结构。水簇阴离子在原则上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级计算处理，大尺寸几乎可以像体积一样。对于非常小的簇（少于10个分子），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，对于较大的集群来说，情况并非如此；既不知道观察到的星团的几种结构形式的确切性质，也不知道将结果正确地外推到整体。在实验方面，这是由于现有测量的技术缺陷，如有限的尺寸范围或缺乏精确的温度控制。利用新一代簇谱装置，我们计划在一个非常广泛的尺寸范围内对温度控制的水簇阴离子和相关系统进行光电子能谱分析。这些结果有望大大提高对水团簇中多余电子的理解，并最终阐明这些性质如何收敛到团簇中。