Institut für Physikalische Chemie, Karlsruher Institut für Technologie, Kaiserstraße 12, 76131 Karlsruhe, Germany.
J Chem Phys. 2010 Dec 14;133(22):224302. doi: 10.1063/1.3514907.
We employ a combination of ion mobility measurements and an unbiased systematic structure search with density functional theory methods to study structure and energetics of gas phase tin cluster cations, Sn(n)(+), in the range of n = 3-15. For Sn(13)(+) we also carry out trapped ion electron diffraction measurements to ascertain the results obtained by the other procedures. The structures for the smaller systems are most easily described by idealized point group symmetries, although they are all Jahn-Teller distorted: D(3h) (trigonal bipyramid), D(4h) (octahedron), D(5h) (pentagonal bipyramid) for n = 5, 6, and 7. For the larger systems we find capped D(5h) for Sn(8)(+) and Sn(9)(+), D(3h) (tricapped trigonal prism) and D(4d) (bicapped squared antiprism) plus adatoms for n = 10, 11, 14, and 15. A centered icosahedron with a peripheral atom removed is the dominant motif in Sn(12)(+). For Sn(13)(+) the calculations predict a family of virtually isoenergetic isomers, an icosahedron and slightly distorted icosahedra, which are about 0.25 eV below two C(1) structures. The experiments indicate the presence of two structures, one from the I(h) family and a prolate C(1) isomer based on fused deltahedral moieties.
我们采用离子淌度测量和无偏系统结构搜索与密度泛函理论方法相结合的方法，研究了气相锡团簇阳离子 Sn(n)(+)（n=3-15）的结构和能态。对于 Sn(13)(+)，我们还进行了被困离子电子衍射测量，以确定其他程序得到的结果。较小体系的结构最容易用理想化的点群对称性来描述，尽管它们都是 Jahn-Teller 扭曲的：对于 n=5、6 和 7，D(3h)（三角双锥）、D(4h)（八面体）、D(5h)（五重锥）。对于较大的体系，我们发现 Sn(8)(+)和 Sn(9)(+)为 capped D(5h)，n=10、11、14 和 15 为 D(3h)（三帽三角棱柱）和 D(4d)（双帽正方形反棱柱）加 adatoms。一个中心的二十面体，去掉一个外围原子，是 Sn(12)(+)的主要特征。对于 Sn(13)(+)，计算预测了一系列几乎等能的异构体，一个二十面体和稍微扭曲的二十面体，它们比两个 C(1)结构低约 0.25 eV。实验表明存在两种结构，一种来自 I(h)家族，另一种是基于融合的 deltahedral 部分的拉长的 C(1)异构体。
