Interaction of long-living solvated electrons with adsorbates at the surface of ice

流体水、水团和水冰具有溶解离子和电子的神奇能力。在冰上，这些溶剂化的电子通过解离电子附着促进电子诱导的反应，例如在大气化学中发生的反应。与气相相比，这种工艺提高了横截面。目前对起作用的物理机制的理解仍然相当不完整。特别是，没有分子尺度的图像可以描述潜在的溶剂化动力学的溶剂化电子状态或在冰表面吸附物与溶剂化电子的相互作用。应当为模型系统开发这样一幅图。为此，我们结合了高度互补的方法，即时间分辨双光子光电子能谱，高分辨率扫描隧道显微镜，以及基于第一性原理和经验方法的理论方法。我们将利用在金属表面制备的晶体冰结构上的长寿命溶剂化电子态，以及吸附的卤代苯分子C6H5F、C6H5Cl和C6H5Br，即具有不同电子亲和度的分子的解离。在这个模型系统上获得的见解一般将有助于理解极性溶剂中的电子溶剂化现象和这些溶剂化电子引起的电子过程。

Fluid water, water clusters, and water ice possess the fascinating ability to solvate ions and electrons. On ice, these solvated electrons facilitate electron-induced reactions via dissociative electron attachment as, for example, takes place in atmospheric chemistry. Such process enhances the cross section as compared to the gas phase. The current understanding of the physical mechanisms at work remains rather incomplete. In particular, no molecular-scale picture exists that describes the underlying solvation dynamics of the solvated electron state or the interaction of the adsorbate with the solvated electron at the ice surface. Such a picture shall be developed for a model system. For this aim, we combine highly complementary approaches, namely, time-resolved two-photon photoelectron spectroscopy, high-resolution scanning tunneling microscopy, and theoretical approaches on the basis of first-principles and empirical methods. We will exploit the long-living solvated electron states at crystalline ice structures prepared on a metal surface and the dissociation of adsorbed halogenated benzene molecules C6H5F, C6H5Cl, and C6H5Br, i.e. of molecules with different electron afinity. The insight gained on this model system will in general contribute to the understanding of the phenomena of electron solvation in polar solvents and electron-induced processes by these solvated electrons.