Photoelectron spectroscopy of large water cluster anions and related systems

• Applicant: Professor Dr. Bernd von Issendorff
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 219187892

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.

• DFG Programme: Research Grants