Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Phys Chem Chem Phys. 2012 Jul 14;14(26):9403-10. doi: 10.1039/c2cp23247b. Epub 2012 Feb 14.
The electronic properties of germanium and tin clusters containing a transition- or lanthanide-metal atom from group 3, 4, or 5, MGe(n) (M = Sc, Ti, V, Y, Zr, Nb, Lu, Hf, and Ta) and MSn(n) (M = Sc, Ti, Y. Zr, and Hf), were investigated by anion photoelectron spectroscopy at 213 nm. In the case of the group 3 elements Sc, Y, and Lu, the threshold energy of electron detachment of MGe(n)(-) exhibits local maxima at n = 10 and 16, while in the case of the group 4 elements Ti, Zr, and Hf, it exhibits a local minimum only at n = 16, associated with the presence of a small bump in the spectrum. A similar behavior is observed for MSn(n)(-) around n = 16, and these electronic characteristics of MGe(n) and MSn(n) are closely related to those of MSi(n). Compared to MSi(n), however, the larger cavity size of a Ge(n) cage allows metal atom encapsulation at a smaller size n. A cooperative effect between the electronic and geometric structures of clusters with a large cavity of Ge(16) or Sn(16) is discussed together with the results of experiments that probe their geometric stability via their reactivity to H(2)O adsorption.
用 213nm 波长的阴离子光电子能谱法研究了含第 3、4、5 族过渡金属或镧系金属原子的锗和锡团簇 MGe(n)（M=Sc、Ti、V、Y、Zr、Nb、Lu、Hf 和 Ta）和 MSn(n)（M=Sc、Ti、Y、Zr 和 Hf）的电子性质。对于第 3 族元素 Sc、Y 和 Lu，MGe(n)(-)的电子离脱阈能在 n=10 和 16 处表现出局部最大值，而对于第 4 族元素 Ti、Zr 和 Hf，仅在 n=16 处表现出局部最小值，这与谱图中存在小凸起有关。MSn(n)(-)在 n=16 附近也表现出类似的行为，这些 MGe(n)和 MSn(n)的电子特性与 MSi(n)密切相关。然而，与 MSi(n)相比，Ge(n)笼较大的空腔尺寸允许金属原子在较小的尺寸 n 下封装。本文讨论了具有较大 Ge(16)或 Sn(16)空腔的团簇的电子和几何结构之间的协同效应，以及通过其对 H(2)O 吸附的反应性来探测其几何稳定性的实验结果。
