Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Inorg Chem. 2011 Aug 15;50(16):7831-7. doi: 10.1021/ic200984q. Epub 2011 Jul 20.
The sulfide-tellurides Ba(3)Cu(17-x)(S,Te)(11) and Ba(3)Cu(17-x)(S,Te)(11.5) were synthesized from the elements in stoichiometric ratios heated to 1073 K, followed by slow cooling to 873 K over 100 h. Ba(3)Cu(17-x)(S,Te)(11) is isostructural to Ba(3)Cu(17-x)(Se,Te)(11) when [S] > [Te], space group R ̅3m, with lattice dimensions of a = 12.009(1) Å, c = 27.764(2) Å, V = 3467.6(5) Å(3), for Ba(3)Cu(15.7(4))S(7.051(5))Te(3.949) (Z = 6). The structure is composed of Cu atoms forming paired hexagonal antiprisms, capped on the two outer hexagonal faces, where each Cu atom is tetrahedrally coordinated by four Q (= S, Te) atoms. The new variant is formed when [Te] > [S]; then Ba(3)Cu(17-x)(S,Te)(11.5) adopts space group Fm3̅m with a = 17.2095(8) Å, V = 5096.9(4) Å(3), for Ba(3)Cu(15.6(2))S(5.33(4))Te(6.17) (Z = 8). This structure consists of eight Te-centered Cu(16) icosioctahedra per cell interconnected by cubic Cu(8) units centered by Q atoms. Electronic structure calculations and property measurements illustrate that these compounds behave as extrinsic p-type semiconductors-toward metallic behavior for the latter compound. With standard oxidation states Ba(2+), Cu(+), and Q(2-), the electron precise formulas are Ba(3)Cu(16)Q(11) and Ba(3)Cu(17)Q(11.5).
硫化物-碲化物 Ba(3)Cu(17-x)(S,Te)(11) 和 Ba(3)Cu(17-x)(S,Te)(11.5) 是由元素在化学计量比下加热到 1073 K 合成的，然后在 873 K 下以 100 h 的速度缓慢冷却。当 [S] > [Te] 时，Ba(3)Cu(17-x)(S,Te)(11) 与 Ba(3)Cu(17-x)(Se,Te)(11) 具有相同的结构，空间群为 R ̅3m，晶格参数为 a = 12.009(1) Å，c = 27.764(2) Å，V = 3467.6(5) Å(3)，对于 Ba(3)Cu(15.7(4))S(7.051(5))Te(3.949) (Z = 6)。结构由形成对六边形反棱柱的 Cu 原子组成，在两个外六边形面上被盖帽，其中每个 Cu 原子由四个 Q (= S, Te)原子四面体配位。当 [Te] > [S] 时形成新变体；然后 Ba(3)Cu(17-x)(S,Te)(11.5) 采用空间群 Fm3̅m，a = 17.2095(8) Å，V = 5096.9(4) Å(3)，对于 Ba(3)Cu(15.6(2))S(5.33(4))Te(6.17) (Z = 8)。该结构由八个以 Te 为中心的 Cu(16) icosioctahedra 组成，每个细胞通过以 Q 原子为中心的立方 Cu(8)单元相互连接。电子结构计算和性能测量表明，这些化合物表现为外禀 p 型半导体-对于后者化合物则表现为金属行为。具有标准氧化态 Ba(2+)、Cu(+)和 Q(2-)，电子精确公式为 Ba(3)Cu(16)Q(11)和 Ba(3)Cu(17)Q(11.5)。
