The two new ternary amalgams K 1−x Rb x Hg 11 [x = 0.472(7)] and Cs 3−x Ca x Hg 20 [x = 0.20(3)] represent two different examples of how to create ternary compounds from binaries by statistical atom substitution. K 1−x Rb x Hg 11 is a Vegard-type mixed crystal of the isostructural binaries KHg 11 and RbHg 11 [cubic, BaHg 11 structure type, space group Pm3̅ m, a = 9.69143(3) Å, Rietveld refinement], whereas Cs 3−x Ca x Hg 20 is a substitution variant of the Rb 3 Hg 20 structure type [cubic, space group Pm3̅ n, a = 10.89553( 14) Å, Rietveld refinement] for which a fully substituted isostructural binary Ca phase is unknown. In K 1−x Rb x Hg 11 , the valence electron concentration (VEC) is not changed by the substitution, whereas in Cs 3−x Ca x Hg 20 , the VEC increases with the Ca content. Amalgams of electropositive metals form polar metal bonds and show "bad metal" properties. By thermal analysis, magnetic susceptibility and resistivity measurements, and density functional theory calculations of the electronic structures, we investigate the effect of the structural disorder introduced by creating mixed-atom occupation on the physical properties of the two new polar amalgam systems.

The new ternary amalgam CsNa2Hg18 was synthesised from the elements in an unconventional low-temperature procedure. It crystallises in a tetragonal structure type (space group I4/mmm, a = 7.3054(7) and c = 20.046 Å) and combines ionic and metallic bonding contributions. In the crystal structure, Cs and Na atoms are embedded in a Hg scaffold with highly covalent Hg–Hg bonding. The alkali metal atoms are coordinated exclusively by Hg atoms in unusual environments with coordination numbers CN = 24 for Cs and CN = 16 for Na. Polar amalgams are suitable model systems for studying the parameters influencing the ’bad metal behaviour’ in polar intermetallic phases. We present structural studies on the basis of powder and single crystal diffraction data together with measurements of the specific resistivity and DFT calculations of the electronic structure. For CsNa2Hg18, a high specific resistivity can be observed, but the Ioffe–Regel saturation of the resistivity is expressed much less than in other polar amalgams.

Earth metals I 2000The Suboxometallates A9MO4 (A: Rb, Cs; M: Al, Ga, In, Fe, Sc). -Single crystals of A 9 MO 4 (A: Rb, Cs; M: Al, Ga, In, Fe, Sc) are prepared from mixtures of M 2 O 3 , A, and A2O in a ratio of 1:5:8 (Ta crucible, 300°C, 2 h). The A9MO4 compounds and (Rb0.57Cs0.43)Cs8GaO4, (Rb0.87Cs0.13)Cs8InO4, Cs9(Al0.51In0.49)O4, and Cs9(Sc0.68In0.32)O4 crystallize in the tetragonal space group I4/mcm with Z = 4 (single crystal XRD) and contain ortho-oxometallate(III) anions in a metallic matrix. -(HOCH*, C.; BENDER, J.; WOHLFARTH, A.; SIMON, A.

Lanthanum I 2700Sheets of La6(C2) Octahedra in Lanthanum Carbide Chlorides -Undulated and Plane. -The new compounds La 8 (C 2 ) 4 Cl 5 (I), Ce 8 (C 2 ) 4 Cl 5 (II), La 14 (C 2 ) 7 Cl 9 (III), La20(C2)10Cl13 (IV), La22(C2)11Cl14, (V), La36(C2)18Cl23 (VI), and La2(C2)Cl (VII) are synthesized from mixtures of Ln, LnCl3 (Ln: La, Ce), and C (Ta ampules, Ar, 970-1080°C, 80% yield (III), 10% yield (IV) and (V)) and characterized by powder and single crystal XRD. Compounds (I), (II), (IV), and (VI) crystallize in the monoclinic space group P2 1 /c with Z = 2 and (V) in the same space group with Z = 1. Compound (III) crystallizes in the monoclinic space group Pc with Z = 2, and (VII) in the monoclinic space group C2/c with Z = 4. The structures contain distorted C2 centered La octahedra forming chains by edge sharing. Three and four such chains join into ribbons, which are connected into undulated layers with Cl atoms between them. -(MATTAUSCH*, H.; SIMON, A.; KIENLE, L.; KOEHLER, J.; HOCH, C.; NUSS, J.; Z. Anorg. Allg.

Three new cesium oxometallates with trigonal-planar [MO 3 ] n− anions (M = Zn, Fe, B) were observed as products of reactions aimed at the formation of alkali metal suboxometallates A 9 MO 4 (A = Rb, Cs; M = Al, Ga, In, Fe, Sc), or as decomposition products thereof. Cs 4 [FeO 3 ], Cs 4 [ZnO 3 ] and Cs 3 [BO 3 ] crystallize with new structure types (Cs 4 [FeO 3 ]: triclinic, space group P1, a = 7.0652(1), b = 7.125(1), c = 9.939(2)Å, α = 80.74(2), β = 71.32(2), γ = 64.04(2) • , Z = 2, Cs 4 [FeO 3 ]: monoclinic, space group P2 1 /c, a = 7.146(4), b = 18.572(1), c = 7.050(4)Å, β = 115.47(4) • , Z = 4, Cs 3 [BO 3 ]: orthorhombic, space group Pnma, a = 10.967(1), b = 10.967(1), c = 10.353(1)Å). In all structures the trigonal-planar anions have no or low point symmetry, but deviate only marginally from ideal6m2 symmetry. The new crystal structures can be derived from simple and highly symmetrical packings of spheres or from known binary structure types.