Li Bin, Corbett John D
Ames Laboratory-DOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Inorg Chem. 2007 Jul 23;46(15):6022-8. doi: 10.1021/ic700519c. Epub 2007 Jun 20.
Six robust intermetallic compounds with cations in three different tunnel-like structures have been synthesized in alkali-metal-Au-In systems via high-temperature solid-state methods and characterized by X-ray diffraction: AAu(4)In(6) [A = K (I), Rb (II), P6m(2), Z = 1], K(1.76(6))Au(6)In(4) (III, I4/mcm, Z = 4), and A(x)Au(2)In(2) [x approximately 0.7, A = K (IV), Rb (V), Cs (VI), P4(2)/nmc, Z = 8]. The first type is constructed from a single cage unit: an alkali-metal-centered 21-vertex polyhedron A@Au(9)In(12) with 6-9-6 arrangement of planar rings. The others contain uniaxial arrays of tunnels built of differently puckered eight- and four-member Au/In rings. The largely different cation distributions depend on the tunnel constitutions and cation sizes. Tight-binding electronic structure calculations by linear muffin-tin-orbital (LMTO) methods were performed for I and idealized III in order to help understand their chemical bonding. These also reveal large differences in relativistic effects for Au d orbitals, as well as for different Au sites in each structure.
通过高温固态法在碱金属 - 金 - 铟体系中合成了六种具有阳离子且阳离子处于三种不同隧道状结构的坚固金属间化合物，并通过X射线衍射对其进行了表征：AAu₄In₆ [A = K (I)，Rb (II)，P6m₂，Z = 1]，K₁.₇₆(₆)Au₆In₄ (III，I4/mcm，Z = 4)，以及AₓAu₂In₂ [x约为0.7，A = K (IV)，Rb (V)，Cs (VI)，P4₂/nmc，Z = 8]。第一种类型由单个笼状单元构成：一个以碱金属为中心的21顶点多面体A@Au₉In₁₂，具有平面环的6 - 9 - 6排列。其他的包含由不同褶皱的八元和四元金/铟环构建的单轴隧道阵列。阳离子分布的显著差异取决于隧道结构和阳离子大小。为了帮助理解它们的化学键合，对I和理想化的III进行了线性 muffin - tin - 轨道（LMTO）方法的紧束缚电子结构计算。这些计算还揭示了金d轨道以及每种结构中不同金位点的相对论效应存在很大差异。
