Electronic Structure of Hydrogen Bonded Clusters

在本研究项目中，我们的目标是生成大尺寸的氢键团簇，并了解团簇的电子结构和几何结构之间的关系。对于氢键团簇，在氢键力的各向异性静电相互作用下，团簇尺寸越大，容易形成规则的周期性结构。基于这些概念，我们尝试构建了用于产生大尺寸星团的星团源，即液体束。利用液体束装置，我们成功地在裸分子挥发时生成了大簇。然而，用多光子电离方法观察到的各簇的电子能谱显示，由于不可避免的破碎过程，总是含有较高簇的成分。另一方面，我们已经成功地产生了大尺寸的簇阴离子，可以很容易地进行批量选择。利用液体束源对大簇阴离子进行光电子能谱分析。

In the present research project, we aimed to generate large sized hydrogen bonded clusters and to understand the relationship between electronic structure and geometric structure of clusters. In the case of hydrogen bonded clusters, regular and periodic strucure may occur easily when cluster size becomes larger in the presence of anisotropic electrostatic interaction of hydrogen bond force. Based on these concept, we have tried to construct the cluster source for the generation of large size clusters, i.e., liquid beam. By the use of liquid beam apparatus, we succeeded in the generation of large clusters when the bare molecule is volatile. However, the observed electronic spectra of respective clusters by means of multiphoton ionization method have revealed to contain always the conponent due to higher clusters because of the inevitable fragmentation process. On the othe hand, we have succeeded in the generation of cluster anions of large size which can be easily mass-selected. Photoelectron spectroscopy of large cluster anions using liquid beam source is now underway in our laboratory.