Cs5Sb8 und β‐CsSb: Zwei neue binäre Zintl‐Phasen

Cs₅Sb₈ and β‐CsSb: Two New Binary Zintl Phases The anion in the crystal structure of the new Zintl phase Cs₅Sb₈ synthesized from the elements (monoclinic, space group P2₁/c, a = 724.4(2) pm, b = 1135.2(3) pm, c = 2750.9(8) pm, β = 96.663(5)°, Z = 4) consists of two and three bonded Sb atoms, which are connected to form puckered nets with 5 and 28 membered rings. β‐CsSb (monoclinic, space group P2₁/c, a = 1519.4(3) pm, b = 734.0(2) pm, c = 1432.2(2) pm, β = 113.661(3)°, Z = 4) crystallizes with a superstructure of the LiAs structure type. As in the α phase (NaP type), twobonded Sb^‐ atoms form neary ideal 4₁ screx chains. In contrast to the α phase the helices have opposite chirality.     

Darstellung und Kristallstruktur von Cs4SnO3

Preparation and Crystal Structure of Cs₄SnO₃ Crystals of Cs₄SnO₃ were synthesized by reaction of SnO with elemental Cs. The compound crystallizes with the triclinic spacegroup P1 with lattice constants a = 737.61(9) pm, b = 1171.3(1) pm, c = 1199.2(1) pm, α = 66.08(3)°, β = 80.88(2)°, γ = 82.28(3)° and Z = 4. The crystal structure exhibits isolated stannate(II) ions [Sn^IIO₃]^4– of ψ-tetrahedral form. Whereas a new structure type is present, there is a close relationship with the structures of the Cs stanntates and plumbates(IV).     

Das Zintl-Konzept als Syntheseprinzip: Darstellung und Kristallstrukturen von K2Ba3Sb4 und KBa4Sb3O

Starting from the Zintl-Concept: Syntheses and Crystal Structures of K₂Ba₃Sb₄ and KBa₄Sb₃O The black, metallic lustrous, air sensitive compounds K₂Ba₃Sb₄ and KBa₄Sb₃O were prepared from melts of mixtures of the elements, in case of KBa₄Sb₃O with a stoichiometric amount of Sb₂O₃. K₂Ba₃Sb₄ crystallizes in the orthorhombic system, space group Pnma (a = 870.5(1) pm, b = 1770.2(2) pm, c = 923.6(1) pm, Z = 4) and is the first Sb compound with only [Sb₂]^4– dumbbells in the anionic partial structure. The compound KBa₄Sb₃O crystallizes in the tetragonal system, space group I4/mcm (a = 882.4(1) pm, c = 1659.4(2) pm, Z = 4). In this structure antimony forms [Sb₂]^4–-dumbbells and isolated ions Sb^3–. Each antimony ion of the dumbbells – in K₂Ba₃Sb₄ as well as in KBa₄Sb₃O – is coordinated in form of a bicapped skew trigonal prism. The isolated Sb^3– ions in KBa₄Sb₃O center bicapped tetragonal antiprisms, the O^2– ions occupy tetrahedral voids.     

Zintl‐Verbindungen mit Gold und Germanium: M3AuGe4 mit M = K,Rb und Cs

Zintl‐Compounds with Gold and Germanium: M₃AuGe₄ with M = K, Rb, Cs Black, brittle single crystals of M₃AuGe₄ with M = K, Rb, Cs were synthesized by reactions of alkali metal azides (MN₃) with gold sponge and germanium powder at T = 1120 K. The structures of the compounds (space group Pmmn, Z = 2, K₃AuGe₄: a = 6.655(1)Å, b = 11.911(2)Å, c = 6.081(1)Å; Rb₃AuGe₄: a = 6.894(1)Å, b = 12.421(1)Å, c = 6.107(1)Å; Cs₃AuGe₄: a = 7.179(1)Å, b = 12.993(2)Å, c = 6.112(2)Å) were determined from X‐ray single‐crystal diffractometry data. The semiconducting compounds contain equation/tex2gif-stack-2.gif[AuGe₄]‐chains with P₄‐analogous Ge₄‐tetrahedra which are connected by μ₂‐bridging gold atoms in a distorted tetrahedral Ge‐coordination.     

Darstellung und Kristallstruktur von Cs2Sb4S7

Preparation and Crystal Structure of Cs₂Sb₄S₇ The first thioantimonite of Cesium has been synthesized and its crystal structure determined. The substance crystallizes monoclinic with spacegroup P2₁/_c. The lattice constants are a = 1111.2(5) pm, b = 1227.1(5) pm, c = 1163.7(5) pm and ß = 97.60(5)°. There are four formula units in the unit cell. Sb–S chains are formed by trigonal SbS₃ pyramids and ψ-trigonal SbS₄ bipyramids.     

Zur Kristallstruktur von Rb2C2 und Cs2C2

On the Crystal Structure of Rb₂C₂ and Cs₂C₂ By reaction of rubidium or caesium solved in liquid ammonia with acetylene AC₂H with A = Rb, Cs was obtained, which was subsequently converted into the binary acetylide A₂C₂ in vacuum at temperatures of 520 K (Rb₂C₂) and 470 K (Cs₂C₂) using a surplus of the respective alkali metal. The crystal structures of the very air sensitive compounds were solved and refined by a combination of both neutron and X‐ray powder diffraction data. Rb₂C₂ as well as Cs₂C₂ coexist in two modifications. The hexagonal modification (P 6 2m, Z = 3) crystallises in the known Na₂O₂ structure type with two crystallographic independent sites for the C₂^2– dumbbells. For the orthorhombic modification (Pnma, Z = 4) a new structure type was found, which is related to the PbCl₂ structure type with ordered C₂^2– dumbbells occupying the Pb sites. Temperature dependent investigations between 4 K and the decomposition temperature by the means of neutron and X‐ray powder diffraction resulted in a very complex dynamic disorder of the C₂ dumbbells, which is still not completely understood. The frequencies of the C–C stretching vibration determined by the help of Raman spectroscopy fit nicely to the results obtained for other alkali metal acetylides and alkali metal hydrogen acetylides. These results seem to indicate that the electronegativity of the alkali metal has a strong influence on the frequency of the C–C stretching vibration.     

Darstellung und Kristallstruktur der Phasen Zr3S4 und Hf3S4

The crystal structure of the Zr₃S₄ phase was confirmed by single crystal work. The structure parameters were refined. An isotypic phase forming a microcrystalline powder could be prepared in the system hafnium/sulphur.     

Darstellung und Kristallstruktur von Rb2Sb4S7

Preparation and Crystal Structure of Rb₂Sb₄S₇ The first thioantimonite of rubidium has been synthesized and its crystal structure determined. The substance crystallizes triclinic with spacegroup P1 . The lattice constants are a = 968.0(5) pm, b = 1193.4(5) pm, c = 723.1(5) pm, α = 87.68(5)°, β = 101.39(5)° and γ = 102.66(5)°. There are two formula units in the unit cell.     

Caesiumchromhalogenide Cs3CrCl6, Cs3Cr2Cl9 und Cs3CrBr6 – Darstellung,Eigenschaften, Kristallstruktur

Cesium Chromium Halides Cs₃CrCl₆, Cs₃Cr₂Cl₉, and Cs₃CrBr₆ – Preparation, Properties, Crystal Structure The crystal structures of Cs₃CrCl₆ and Cs₃Cr₂Cl₉ were determined and redetermined by X‐ray single‐crystal studies (space group Pnnm, Z = 6, a = 1115.6(2) pm, b = 2291.3(5) pm, c = 743.8(1) pm, R_f = 7.73%, 1025 unique reflections with I > 2σ(I) (Cs₃CrCl₆); P6₃/mmc, Z = 2, a = 721.7(2) pm und c = 1791.0(1) pm; R_f = 2.06%, 395 unique reflections with I > 2.5σ(I) (Cs₃Cr₂Cl₉). The structure of Cs₃CrCl₆ consists of two different isolated CrCl₆ octahedra and five crystallographic different Cs⁺ ions. The CrCl₆ octahedra form ropes in the direction [001]. Because of orientational disordering of the Cr(1)Cl₆ octahedra and the an only half‐occupation of some cesium and chlorine sites Cs₃CrCl₆ is strongly disordered in direction of the (020) plane. The ionic conductivity of Cs₃CrCl₆, which was expected owing to the great disorder, however, is with 7.3 × 10^–5 Ω^–1 cm^–1 at 740 K relatively small. The compound Cs₃CrBr₆, which was firstly prepared by quenching stoichiometric amounts of CsBr and CrBr₃ from 833 K, is metastable at ambient temperature. It is probably isostructural to Cs₃CrCl₆ as shown by X‐ray powder photographs.     

Korrektur zur Kristallstruktur von „Cs4PbO3”︁ und die Strukturverwandtschaft zwischen den Modifikationen von Cs4PbO4

Correction of the Crystal Structure of “Cs₄PbO₃” and the Structural Relationship between the Modifications of Cs₄PbO₄ The compound that has been described as Cs₄PbO₃ really is Cs₄PbO₄. It does not crystallize in the space group P2₁, as assumed, but in P2₁/c. The observed fictitiuous violation of the extinction law for the c glide plane is due to twinning. The structure was refined using the original data as well as new data from an untwinned crystal. The denomination β-Cs₄PbO₄ is used to distinguish this structure from another known modification (α-Cs₄PbO₄). Both structures, α-Cs₄PbO₄ and β-Cs₄PbO₄, can be derived from the sphere packing of γ-plutonium when certain voids in its packing are occupied with oxygen atoms.     

Zintl‐Anionen des Siliciums in den Halogeniden La3Cl2Si3 und La6Br3Si7

Zintl Anions of Silicon in the Halides La₃Cl₂Si₃ and La₆Br₃Si₇ La₃Cl₂Si₃ and La₆Br₃Si₇ are prepared at temperatures of around 950 °C from LaX₃ (X = Cl, Br), La metal and Si as starting materials. La₃Cl₂Si₃ crystallizes in C2/m with a = 1802(3), b = 420.6(4), c = 1058(2) pm, β = 97.9(2)°, and La₆Br₃Si₇ in Pmmn mit a = 1686.9(2), b = 412.93(11), c = 1185.2(1) pm. In both compounds the Si atoms are located in trigonal prisms of La atoms, which are connected through common triangular and rectangular faces to form layers. The bromine atoms connect the metal atom double layers. In La₃Cl₂Si₃ the Si atoms form zig‐zag chains, in La₆Br₃Si₇ chains build up from ‐connected Si₁₂ rings. Both compounds are metallic conductors.     

RbSb2 – Eine mit KSb2 verwandte Zintl‐Phase

RbSb₂ – A Zintl Phase related to KSb₂ The electron‐precise Zintl compound RbSb₂, which was known to melt incongruently at 418 °C, has been prepared in pure phase from elemental rubidium and antimony in sealed tantalum crucibles. In accordance with the ribbon‐shaped antimonide anions, the compound crystallizes with extremely thin intergrown, mechanically and chemically very sensitive needles of dark‐metallic lustre. The crystal structure could be determined and refined using single crystal x‐ray data (monoclinic, space group C2/m, a = 1403(2), b = 414.0(4), c = 855.7(14) pm, β = 104.45(12)°, Z = 4, R1 = 0.0901) despite the poor quality of the crystals. It shows fused six‐membered rings of two‐ and three‐bonded Sb atoms forming ribbons running along the monoclinic b axis, which can be interpreted as sections of the elemental structure of antimony (d_Sb‐Sb = 281.9(5) and 286.0(9) pm respectively). The structure of RbSb₂ is thus closely related to that of KSb₂, which exhibits identical antimony anions. Compared to the potassium compound, the ribbons are reoriented against each so that the coordination number of the A counter ions is increased from 6 + 2 (for A = K) to 8 + 2 (for A = Rb). The results of a FP‐LAPW band structure calculation of RbSb₂ are used to explain the chemical bonding in this classical Zintl phase with a calculated indirect band gap of 0.38 eV.     

Zur Darstellung und Kristallstruktur von Rb2Sb4S7

On the Preparation and Crystal Structure of Rb₂Sb₄S₇ Rb₂Sb₄S₇ was prepared by methanolothermal reaction of Rb₂CO₃ with Sb₂S₃ at a temperature of 140°C. An X-ray structural analysis demonstrated that the compound contains polythioantimonate(III) anions (Sb₄S₇^2?)_n, for which the basic element is a ψ-trigonal (SbS₄)-bipyramid. Edge bridged SbS₄ polyhedra build vierer single chains (Sb₄S₈^4?)_n, which are linked via two symmetry related S atoms with neighbouring chains so that an (Sb₄S₇^2?)_n sheet is formed.     

Die Kristallstrukturen von (DDI)2[Sb2F6O] und (DDI)2[Sb3F7O2] (DDI = 1, 3‐Diisopropyl‐4, 5‐dimethylimidazolium) — Ein Beitrag zur Hydrolyse von SbF3 [1]

The Crystal Structures of (DDI)₂[Sb₂F₆O] and (DDI)₂[Sb₃F₇O₂] (DDI = 1,3‐Diisopropyl‐4,5‐dimethylimidazolium) — a Contribution to the Hydrolysis of SbF₃ [1] The salts (DDI)₂[Sb₂F₆O] ( 2 ) and (DDI)₂[Sb₃F₇O₂] ( 3 ), (DDI = 1,3‐diisopropyl‐4,5‐dimethylimidazolium) are obtained by hydrolysis of C₁₁H₂₀N₂SbF₃ ( 1 ). The anion [Sb₂F₆O]^2? consists of two SbF₂ fragments linked by a symmetrical oxygen bridge and two unsymmetrical fluorine bridges to form a distored ψ‐octahedral coordination sphere at the antimony atoms. In [Sb₃F₇O₂]^2?, two SbF₂ units are linked by a symmetrical fluorine bridge, while the third antimony atom is connected with each SbF₂ fragment by a symmetrical oxygen and an unsymmetrical fluorine bridge. The antimony atoms adopt the centres of strongly distored ψ‐polyhedra.     

Darstellung und Kristallstruktur des Lithium‐Strontium‐Hydridnitrids LiSr2H2N

Synthesis and Crystal Structure of the Lithium Strontium Hydride Nitride LiSr₂H₂N LiSr₂H₂N was synthesized by the reaction of LiH and Li₃N with elemental strontium in sealed tantalum tubes at 650 °C within seven days. This second example of a quaternary hydride nitride crystallizes orthorhombically in space group Pnma (no. 62) with the lattice constants a = 747.14(5) pm, b = 370.28(3) pm and c = 1329.86(9) pm (Z = 4). Its crystal structure contains both kinds of anions H^? and N^3? in a sixfold distorted octahedral metal cation coordination each. The coordination polyhedra [(H1)Sr₅Li]¹⁰⁺, trans‐[(H2)Sr₄Li₂]⁹⁺ and [NSr₅Li]⁸⁺ are connected via edges and corners to form a three‐dimensional network. Two crystallographically different Sr²⁺ cations exhibit a sevenfold monocapped trigonal prismatic coordination by H^? and N^3? with [(Sr1)H₅N₂]^9? and [(Sr2)H₄N₃]^11? polyhedra, wheras Li⁺ shows a nearly planar fourfold coordinative environment ([LiH₃N]^5?). Cationic double chains of edge‐shared [NSr₅Li]⁸⁺ octahedra dominate the structure according to . Running parallel to the [0 1 0] direction, they are bundled like a hexagonal rod‐packing which is interconnected by H^? anions within the (0 0 1) plane first and finally even in the third dimension (i. e. along [0 0 1]). Therefore the structure of LiSr₂H₂N is compared to that one of the closely related quaternary hydride oxide LiLa₂HO₃.     

Verfeinerung der Kristallstruktur des Dicaesium-Tetraazido-Zinkates Cs2Zn(N3)4 und die Kristallstrukturen komplexer Zinkazide

Summary The crystal structure of dicesium-tetraazido-zincate, Cs₂Zn(N₃)₄, has been refined from single crystal X-ray-diffractometer data. The previously reported orthorhombic structure, consisting of isolated Zn(N₃)₄-tetrahedra was confirmed and improved lattice parameters and atomic distances were determined. The azide groups are asymmetric and the coordination of central nitrogen atoms to cesium was observed. A table of structure data and mean atomic distances for fourteen zinc-azide compounds is added and the structures are discussed.

Herrn Prof. Dr. Karl Torkar zum 70. Geburtstag gewidmet     

Synthese und Kristallstruktur von Cs3AuO2

Synthesis and Crystal Structure of Cs₃AuO₂ Bright orange single crystals of Cs₃AuO₂, sensitive to moisture and atmosphere, are obtained by reacting CsAu with a 1 : 1 molar mixture of Cs₂O and CsO₂ (CsAu : Cs₂O : CsO₂ = 3 : 2 : 2) in sealed silver crucibles under argon atmosphere at 380 °C for a period of 6 days. The crystal structure (Pearsoncode mP72, P2₁/n, a = 1019.6(3), b = 1984.3(7), c = 1028.5(4) pm, β = 93.96(1)°, Z = 12, 2562 reflections mit I_o > 2σ(I), R₁ = 0.0662, wR₂ = 0.1660) is characterized by the presence of dumb‐bell‐shaped [O–Au–O]‐moieties (d(Au–O) = 200,8(2) pm), a common feature of oxoaurates(I).     

Wasserfreie Sulfate der Selten‐Erd‐Elemente: Synthese und Kristallstruktur von Y2(SO4)3 und Sc2(SO4)3

Anhydrous Sulfates of Rare Earth Elements: Syntheses and Crystal Structures of Y₂(SO₄)₃ and Sc₂(SO₄)₃ The reaction of YCl₃ and Li₂SO₄ in sealed gold ampoules yields colorless single crystals of Y₂(SO₄)₃. According to the X‐ray single crystal determination the compound crystallizes with orthorhombic symmetry (Pbcn, Z = 4, a = 1273.97(13), b = 916.76(9), c = 926.08(7) pm, R_all = 0.0274). The crystal structure is buildt up from [YO₆] octahedra and sulfate tetrahedra connected via all vertices. In the same way [ScO₆] octahedra and sulfate groups are connected in the crystal structure of Sc₂(SO₄)₃ (trigonal, R‐3, Z = 6, a = 870.7(1), c = 2247.0(4) pm, R_all = 0.0255). Single crystals of Sc₂(SO₄)₃ were obtained via crystallisation of powder samples from a NaCl melt. The crystal structures of both compounds are closely related to each other and to the binary sulfides Rh₂S₃ and Lu₂S₃; the structures are the same with the complex SO₄^2– ions replacing the S^2– ions of the sulfides.     

Reactions of Polyarsenides with Acetylene: Synthesis and Characterization of [Cs([18]crown‐6)]2As7C14H11·6NH3 and As2C6H6

The reaction of Cs₃As₇ with diphenylacetylene in the presence of 18 crown‐6 in liquid ammonia results in the formation of the new compound [Cs( 18 crown‐6)]₂As₇C₁₄H₁₁ · 6NH₃, which crystallizes in black monoclinic crystals. It contains the first monosubstituated heptaarsenide anion with a hydrocarbon‐only substituent and theoretical calculations show a significant influence of the organic substituent on the electronic structure within the cage. The (Z)‐1, 2‐diphenylethenyl‐heptaarsenide di‐anion can be seen as the first step towards the formation of 1, 2,3‐triarsolides. Further experiments regarding the reaction of Rb₃As₁₁ and Cs₃As₁₁ with acetylene gas in liquid ammonia reveal the formation of the diarsabarrelene As₂C₆H₆, which crystallizes as colorless orthorhombic crystals. Calculations based on the structural data obtained by X‐ray crystallography show the electronically inert character of the arsenic lone pair.