Ion Mobility Studies of the Structures of Atomic Clusters

实验物理化学项目支持Martin F. Jarrold继续研究，利用气相离子迁移率测量确定中型团簇的结构。气相离子在弱电场作用下通过缓冲气体的速度取决于其几何形状。虽然可以从移动度中推断出一些几何形状的信息，但可以有多个几何形状具有相同的移动度。因此，Jarrold建议将最近建造的高分辨率仪器与磁瓶阴离子光电子能谱仪耦合在一起。使用这种方法，光电子能谱将被测量为碳、硅和锗多达数百个原子团簇的几何形状和团簇大小的函数。原子团簇是包含几个到几千个原子的小块材料。由于各种原因，这些物种的物理和化学性质与散装材料不同。检查属性并确定它们如何随着簇大小的变化而变化是过去十年来主要研究工作的对象。结构通常控制着任何材料的物理和化学性质。因此，关于原子团簇几何结构的信息对于理解它们的大小依赖性质是至关重要的。这些研究将大大增加我们对第4族（碳、硅和锗）元素簇的结构和键合的理解。

The Experimental Physical Chemistry Program support Martin F. Jarrold in his continuing studies to determine the structure of medium-sized clusters using gas phase ion mobility measurements. The speed with which a gas phase ion moves through a buffer gas under the influence of a weak electric field depends on its geometry. Although some information about the geometries can be deduced from the mobilities, more than one geometry can have the same mobility. Thus, Jarrold proposes to couple a recently-constructed high resolution apparatus with a magnetic-bottle anion photoelectron spectrometer. Using this approach, photoelectron spectra will be measured as a function of geometry and cluster size for carbon, silicon, and germanium clusters of up to hundreds of atoms. Atomic clusters are small pieces of material containing from a few to several thousand atoms. For a variety of reasons, the physical and chemical properties of these species are different than those of the bulk material. Examining the properties and determining how they change as a function of cluster size has been the object of a major research effort for the last ten years. Structure generally controls the physical and chemical properties of any material. Thus information about the geometric structure of atomic clusters is critical for understanding their size-dependent properties. These studies will substantially increase our understanding of the structure and bonding in clusters of the Group 4 (carbon, silicon and germanium) elements.