Lyon Jonathan T, Gruene Philipp, Fielicke André, Meijer Gerard, Janssens Ewald, Claes Pieterjan, Lievens Peter
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
J Am Chem Soc. 2009 Jan 28;131(3):1115-21. doi: 10.1021/ja807518y.
We present gas-phase infrared spectra for small silicon cluster cations possessing between 6 and 21 atoms. Infrared multiple photon dissociation (IR-MPD) of these clusters complexed with a xenon atom is employed to obtain their vibrational spectra. These vibrational spectra give for the first time experimental data capable of distinguishing the exact internal structures of the silicon cluster cations. By comparing the experimental spectra with theoretical predictions based on density functional theory (DFT), unambiguous structural assignments for most of the Si(n)(+) clusters in this size range have been made. In particular, for Si(8)(+) an edge-capped pentagonal bypriamid structure, hitherto not considered, was assigned. These structural assignments provide direct experimental evidence for a cluster growth motif starting with a pentagonal bipyramid building block and changing to a trigonal prism for larger clusters.
我们展示了含有6至21个原子的小硅团簇阳离子的气相红外光谱。利用这些与氙原子络合的团簇的红外多光子解离（IR-MPD）来获得它们的振动光谱。这些振动光谱首次给出了能够区分硅团簇阳离子确切内部结构的实验数据。通过将实验光谱与基于密度泛函理论（DFT）的理论预测进行比较，对该尺寸范围内的大多数Si(n)(+)团簇进行了明确的结构归属。特别是，对于Si(8)(+)，确定了一种迄今未被考虑的边缘封顶五角双锥结构。这些结构归属为从五角双锥构建块开始并向更大团簇转变为三角棱柱的团簇生长模式提供了直接的实验证据。
