Über die Kristallstruktur der Phase La5B2C6

On the Crystal Structure of the Phase La₅B₂C₆ A homogeneous sample of La₅B₂C₆ annealed at 1000 °C was investigated by X‐ray powder and single‐crystal as well as electron diffraction. The crystal structure was refined in space group P4/ncc (a = 8.590(1) Å, b = 12.398(1) Å, Z = 4, ρ_calc = 5.723 g/cm, ρ_exp = 5.70 g/cm) allowing for anharmonic displacement parameters for the metal atoms. The structure contains twofold disordered CBCC units in bicapped tetragonal antiprismatic coordination in contrast to C₂ and CBC units in earlier investigations.     

Über die Synthese von Erdalkalimetalldihalogeniden und die Strukturen von Ca3Br2CBN und Sr3Cl2CBN

On the Synthesis of Alkaline-Earth Dihalides and the Structures of Ca₃Br₂CBN and Sr₃Cl₂CBN The reaction of alkaline-earth carbonates with ammonium chloride or bromide yields alkaline-earth dihalides at relatively low temperatures (300°C). Ca₃Br₂CBN and Sr₃Cl₂CBN were synthesized in sealed niobium containers at 950°C from the metal, its dihalide, boron nitride and graphite. The crystal structure of Sr₃Cl₂CBN was refined from single crystal data. Sr₃Cl₂CBN crystallizes isotypic with Ca₃Cl₂CBN in the orthorhombic space group Pnma (No. 62) with a = 1448.4(2) pm b = 405.46(5) pm, c = 1170.0(1) pm. The lattice constants of Ca₃Br₂CBN and Sr₃Cl₂CBN were determined by orthorhombic indexing of the powder patterns (Ca₃Br₂CBN: a = 1444.3(2) pm, b = 390.64(6) pm, c = 1139.2(2) pm; Sr₃Cl₂CBN: a = 1444.0(4) pm, b = 405.27(8) pm, c = 1167.8(2) pm). There was no success in preparing homologues with Barium.     

Synthese und Kristallstruktur des Goldclusters [Au16(AsPh3)8Cl6]

Synthesis and Structures of the Gold Cluster [Au₁₆(AsPh₃)₈Cl₆] Reduction of Ph₃AsAuCl with NaBH₄ in ethanol yields the gold cluster [Au₁₆(AsPh₃)₈Cl₆]. It can be crystallized from dichloromethane/diisopropyl ether in form of dark red, light sensitive crystals with the space group P2₁/n and a = 1777.68(8), b = 3372.7(1), c = 2696.2(1)pm, β = 94.166(6)°, Z = 4). The inner skeleton of the 16 Au atoms consists of a centered icosahedron of which one of the corners binds to three additional Au atoms forming a tetrahedron pendent. The shortest Au–Au distances of 264.3 to 266.6 pm correspond to the bonds to the three external Au atoms. Within the icosahedron the distances between the central atom and the peripheral atoms (273.0–279.1 pm) are distinctly shorter than the distances between the peripheral atoms (283.6–299.0 pm).     

Über die Synthese und spektroskopische Charakterisierung von Strontium‐ und Bariumtetrabromoferrat(III) und die Kristallstruktur von Ba(FeBr4)2

Preparation and Spectroscopic Characterization of Strontium and Barium Tetrabromoferrate(III) and the Crystal Structure of Ba(FeBr₄)₂ The synthesis of the hitherto unknown bromoferrates(III) of alkaline‐earth metals was carried out by heating mixtures of the metals or the binary bromides together with bromine at temperatures of 450 °C and pressures of up to 1500 bar in closed quartz ampoules. The attempts have been successful only with the larger cations of Sr and Ba. In the case of Be, Mg, and Ca only mixtures of the binary bromides with FeBr₃ could be received. By analysis of the Raman and electronic spectra the dark red compounds of Sr and Ba have been characterized as ternary tetrabromoferrates(III) containing tetrahedral FeBr₄ anions. The composition M(FeBr₄)₂ (M = Sr, Ba) has been determined by potentiometric and titrimetric analysis and thermal degradation by thermogravimetry. A single crystal structure determination of Ba(FeBr₄)₂ confirmed the spectroscopic assignments. The orthorhombic crystal structure (space group Pbca; a = 13.054(3) Å; b = 11.093(2) Å; c = 21.764(4) Å; Z = 8) consists of FeBr₄ and BaBr₉ polyhedra.     

Darstellung und Kristallstruktur von (NH4)2[V(NH3)Cl5]. Die Kristallchemie der Salze (NH4)2[V(NH3)Cl5], [Rh(NH3)5Cl]Cl2 und M2VXCl5 mit M = K,NH4, Rb,Cs und X = Cl,O

Preparation and Crystal Structure of (NH₄)₂[V(NH₃)Cl₅]. The Crystal Chemistry of the Compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂, and M₂VXCl₅ with M = K, NH₄, Rb, Cs and X ? Cl, O (NH₄)₂[V(NH₃)Cl₅] crystallizes like [Rh(NH₃)₅Cl]Cl₂ in the orthorhombic space group Pnma with Z = 4. The compounds are built up by isolated NH₄⁺ or Cl^? and complex MX₅Y ions. The following distances have been observed: V? N: 213.8, V? Cl: 235.8–239.1, Rh? N: 207.1–208.5, Rh? Cl: 235.5 pm. Both structures differ from the K₂PtCl₆ type mainly in the ordering of the MX₅Y polyhedra. The compounds M₂VCl₆ and M₂VOCl₅ with M = K, NH₄, Rb, and Cs crystallize with exception of the orthorhombic K₂VOCl₅ in the K₂PtCl₆ type. The ordering of the MX₅Y polyhedra in the compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂ and K₂VOCl₅ enables a closer packing.     

Über Sulfide der vierten Hauptgruppe vom Typ AIIBIVS3 und die Kristallstruktur des SnGeS31)

Inhaltsübersicht. Die Elemente der vierten Hauptgruppe bilden vier Sulfide vom Typ A^IIB^IVS₃: SnGeS₃, PbGeS₃, SnSnS₃, PbSnS₃. Die Verbindungen lassen sich durch Reaktion der Elemente sowie der binären Sulfide darstellen. Es können gute Einkristalle erhalten werden. Auf Grund chemischer, physikalischer und struktureller Eigenschaften lassen sich die Sulfide in zwei Gruppen einteilen. Bestimmend hierfür ist das Element in der Oxydationsstufe +IV. Die Struktur der isotypen Verbindungen SnGeS₃ und PbGeS₃ wurde durch eine vollständige Röntgenstrukturanalyse des SnGeS₃ bestimmt. Cherakteristisch für die Struktur sind Ketten aus eckenverknüpften GeS₄-Tetraedern, die über Sn-Atome zu stark gewellten Schichten vernetzt sind. Type A^IIB^IVS₃ Sulfides of the Fourth Main Group and the Crystal Structure of SnGeS₃ Abstract. The group IV elements form sulfides of the type A^IIB^IVS₃: SnGeS₃, PbGeS₃, SnSnS₃, PbSnS₃. The compounds are formed through the reaction of the elements and of the binary sulfides. Good single crystals are obtained. The sulfides can be sorted into two groups due to their physical, chemical and structural properties. The element in the oxidation state +IV determines these properties. The structure of the isotypic compounds SnGeS₃ and PbGeS₃ was determined by a complete x-ray structure analysis of SnGeS₃. Characteristic for the structure are chains of GeS₄ tetrahedra sharing to vertices each. The chains are linked into corrugated layers by the Sn atoms.     

Über die oxidative Fluorierung von (CF3)(R) (R = CF3, Cl) und die Kristallstruktur von (CF3)(Cl)F+ AsF6−

Oxidative Fluorination of (CF₃)(R) (R = CF₃, Cl) and the Crystal Structure of (CF₃)(Cl) F⁺ AsF₆^? Oxidative fluorination of (CF₃)(R) (R = CF₃, Cl) with XeF⁺MF₆^? (M = As, Sb) in anhydrous HF results in formation of monofluorsulfonium hexafluorometalates. The salts are characterized by vibrational, NMR, and mass spectra. (CF₃)(Cl)F⁺ AsF₆^? crystallizes in the monoclinic space group P2₁/c with a = 9.955(10) Å, b = 11.050(5) Å, c = 12.733(15) Å, β = 97.77(5)°, and Z = 4.     

Über Oxoplumbate(IV).IDie Kristallstruktur von Rb2PbO3

Rb₂PbO₃ [single crystals, 244 (hkl)] crystallises orthorhombic [D? Pmcn] with a = 10.8, b = 7.49, c = 5.98 Å [Z = 4, d_pyk = 5.69, d_rö = 5.80 g · cm^?3], Rb in 8(d) Pb in 4 (c), O_I in 4 (c). The parameters are shown in table 2. The MADELUNG Part of Lattice Energy of Rb₂RBO₃ and structurally related models are calculated and discussed in detail. Characteristic for the structure are ldimensional chains consisting of alternatingly directed pseudo-tetragonal pyramids, ∞¹[PbO₁O_4/2], connected via common basis edges.     

Über den Einfluß von Substitution auf die Kristallstruktur von SrNi2P2

About the Effect of Substitution on the Crystal Structure of SrNi₂P₂ With several series of mixed crystals the effect of substitution on the crystal structure of SrNi₂P₂ (polymorphic, the structures are variants of the ThCr₂Si₂ type) is investigated by X-ray methods. In the compound Ni completely can be substituted by Co and Cu respectively and also P by As; in Sr_1–xCa_xNi₂P₂ there is a gap of the miscibility between 0.3 ≤ x ≤ 0.6. A low substitution of the several elements more than proportionally changes the structure parameters. In this range the mixed crystals with Ca, Cu, and As, respectively, undergo first order phase transitions with significant changes of the bond distances, which will be interpreted by the results of band structure calculations.     

Rubidium-decaamidodichromat(III), Rb4Cr2(NH2)10 – Synthese und Kristallstruktur

Rubidium Decaamidodichromate(III), Rb₄Cr₂(NH₂)₁₀ – Synthesis and Crystal Structure The reaction of chromium(III) with rubidium amide in a molar ratio of Cr(NH₂)₃/RbNH₂ = 1 : 1.75 at 140 °C and p(NH₃) = 3 kbar in a high-pressure autoclave results after 90 days in dark violet crystals of Rb₄Cr₂(NH₂)₁₀. Structure determination was done by single crystal X-ray methods:Pna2₁ (No. 33), Z = 4, a = 12.244(3) Å, b = 6.727(1) Å, c = 19.775(5) Å, N(F²_o > 3σ(F²_o)) = 1046, N(Var.) = 94, R/R_w = 0,051/0,059&#TAB;The structure of Rb₄Cr₂(NH₂)₁₀ contains isolated, face-sharing N-octahedra around two Cr³⁺-ions giving [Cr(NH₂)₃(NH₂)_3/2]₂^3–. These are arranged to oneanother following the motif of a hexagonal closest packing. They are connected via Rb⁺- and one further amide ion not bound to Cr³⁺. The compound is characterized by thermoanalytical and IR-/Raman-spectroscopic measurements.     

Thermodynamik und Kinetik der Xa-Substitution bei den Komplexen [W6Cl8]X6a(2−) und [Mo6Cl8]X6a(2−) (X = Cl,Br, J)

Thermodynamics and Kinetics of the X^a-Substitution of [W₆Cl₈]X₆^a(2?) and [Mo₆Cl₈]X₆^a(2?) Complexes; (X = Cl, Br, I) The title subject has been investigated in different solvent mixtures (see “Inhaltsübersicht”). In some cases the progress of the reaction has been followed by an emf method; in most cases the reaction was stopped after definite times by precipitation of the oxiniumsalts. Thermodynamics. For equilibria of the type (a) one finds the constant \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm C} = \frac{{[{\rm Br}^{\rm a} ][{\rm Cl}^ - ]}}{{[{\rm Cl}^{\rm a} ][{\rm Br}^ - ]}} $\end{document}, where [Br^a] and [Cl^a] mark the total number of Br or Cl occupying X^a-positions of the complex. The X^a-positions are thermodynamically equivalent, the substitution proceeds statistically, so that the steps of reaction (a) with the equilibrium constants K₁ to K₆ are given by \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm K} = \frac{{{\rm W}({\rm hin})}}{{{\rm W}({\rm r\ddot uck})}} \cdot {\rm C} $\end{document} if W(hin) and W(rück) describe the probability of the forward and the back reaction. Similarly in some simple complexes (e. g. Irx₆^2?);PdX₄^2? the statistical effect plays a dominating role. The kinetics may be described as (b) The aquotation step is rate determining. Consequently the reaction of the first order. Rate constants for the forward and the reversed reaction between 0 and 25°C have been measured. The activation energy is ≈ 18 kcal. With the molybdenum complexes the X^a-substitutions is about 10 times faster as with the tungsten complexes.     

Isotype Strukturen einiger Hexaamminmetall(II)-halogenide von 3d-Metallen: [V(NH3)6]I2, [Cr(NH3)6]I2, [Mn(NH3)6]Cl2, [Fe(NH3)6]Cl2, [Fe(NH3)6]Br2, [Co(NH3)6]Br2 und [Ni(NH3)6]Cl2

The Structures of some Hexaammine Metal(II) Halides of 3 d Metals: [V(NH₃)₆]I₂, [Cr(NH₃)₆]I₂, [Mn(NH₃)₆]Cl₂, [Fe(NH₃)₆]Cl₂, [Fe(NH₃)₆]Br₂, [Co(NH₃)₆]Br₂ and [Ni(NH₃)₆]Cl₂ Crystals of yellow [V(NH₃)₆]I₂ and green [Cr(NH₃)₆]I₂ were obtained by the reaction of VI₂ and CrI₂ with liquid ammonia at room temperature. Colourless crystals of [Mn(NH₃)₆]Cl₂ were obtained from Mn and NH₄Cl in supercritical ammonia. Colourless transparent crystals of [Fe(NH₃)₆]Cl₂ and [Fe(NH₃)₆]Br₂ were obtained by the reaction of FeCl₂ and FeBr₂ with supercritical ammonia at 400°C. Under the same conditions orange crystals of [Co(NH₃)₆]Br₂ were obtained from [Co₂(NH₂)₃(NH₃)₆]Br₃. Purple crystals of [Ni(NH₃)₆]Cl₂ were obtained by the reaction of NiCl₂ · 6H₂O and NH₄Cl with aqueous NH₃ solution. The structures of the isotypic compounds (Fm3 m, Z = 4) were determined from single crystal diffractometer data (see “Inhaltsübersicht”). All compounds crystallize in the K₂[PtCl₆] structure type. In these compounds the metal ions have high-spin configuration. The orientation of the dynamically disordered hydrogen atoms of the ammonia ligands is discussed.     

Über die Trithiocyanatoargentate Rb2Ag(SCN)3 und Cs2Ag(SCN)3

On the Trithiocyanatoargentates Rb₂Ag(SCN)₃ and Cs₂Ag(SCN)₃ The trithiocyanatoargentates Rb₂Ag(SCN)₃ and CsAg(SCN)₃ are obtained by crystallization from highly concentrated aqueous solutions. In the crystal structures the Ag atoms are surrounded tetrahedrally by the S atoms of 4 SCN groups. These Ag(SCN)₄ tetrahedra are connected by common corners to polymer \documentclass{article}\pagestyle{empty}\begin{document}$ {}_\infty ^1 \left[{{\rm Ag}\left({{\rm SCN}} \right)_2 \left({{\rm SCN}_{2/2}} \right)} \right] $\end{document}¹[Ag(SCN)₂(SCN)_2/2] anion in Rb₂Ag(SCN)₃, whereas dimeric Ag₂(SCN)₆ anions were found in the Cs compound.     

Über die Systeme AJ/CoJ2 und die kristallchemischen Beziehungen in der Gruppe der Doppelhalogenide AnCoX(n+2) mit X = Cl,Br, J [1]

The Systems AI/CoI₂ (A = Alkali Metal, Tl, Ag) and the Crystal Chemistry of the Double Halides A_nCoX_(n+2) with X = Cl, Br, I The systems AI/CoI₂ (A = Cs, Rb, K, Tl, Na, Ag) were investigated by differencethermal analysis. The systems of NaI and AgI are found to be eutectical. A compound A₂CoI₄ always exists in the other systems. Cs₂CoI₄ crystallizes in the β-K₂SO₄ type with a coordination number (C.N.) for Cs equal to 9/10. Results obtained with single crystal technique reveal for the first time that among the double halides Rb₂CoI₄ is of the monoclinic Sr₂GeS₄ type (C. N. for Rb = 6(+2)). The compounds K₂CoJ₄, Tl₂CoJ₄, T-K₂CoBr₄, and T-Tl₂CoBr₄ are isotypic. Both structure groups are characterized by isolated CoX₄^2? tetrahedra. Reflectance spectra and magnetic susceptibilities can be explained on the basis of crystal field theory. – Our results close presently existing gaps in the knowledge on systems of CoBr₂ and CoCl₂ too.     

Darstellung von trans-[Mo6Cl8]Cl4Br22−ausgehend von kristallisierten [Mo6Cl8]Cl4(H2O)2 und die Kristallstruktur von [(C6H5)4As]2[Mo6Cl8]Cl4Br2

Preparation of trans-[Mo₆Cl₈]Cl₄Br₂^2? Starting from Crystalline [Mo₆Cl₈]Cl₄(H₂O)₂ and Crystal Structure of [(C₆H₅)₄As]₂[Mo₆Cl₈]Cl₄Br₂ The synthesis of the title compound is successful if the crystallized [(Mo₆Cl₈)Cl₄(H₂O)₂] containing the H₂O molecules in trans-position reacts with HBr + [(C₆H₅)₄As]Br in ethanol in a heterogeneous reaction. The X-ray structure investigation confirms the existence of discrete trans-Br-substituted cluster anions of composition [(Mo₆Cl₈)Cl₄Br₂]^2? in the crystal. The reaction in homogeneous solutions proceeds to Br-enriched compounds. [(C₆H₅)₄As]₂[(Mo₆Cl₈)Cl₄Br₂] crystallizes in the triclinic space group P¯1 with a = 11.071(2), b = 11.418(2), c = 12.813(2) Å, α = 116.10(2), β = 95.27(2) and γ = 94.41(2)° (?133°C). The crystal structure at ?133°C was determined from single crystal X-ray diffraction data (R₁ = 0.026). The [(Mo₆Cl₈)Cl₄Br₂]^2?-anions are not completely ordered but distributed statistically among the three positions which are possible within the limits of the ordered [Mo₆Cl₈]-cores (ratio 11:5:4). The frameworks of the anions consist of Mo₆ cluster units with (slightly distorted) octahedral arrangement of the metal atoms (d(Mo? Mo): 2.600(1) up to 2.614(1) Å), which are coordinated by the halogeno ligands in a square-pyramidal manner. The details of the structure will be discussed and compared with similar [(Mo₆X₈)Y₄] cluster units (X, Y ? Cl, Br).     

Darstellung und Kristallstruktur von (CH3NH3)8[NdCl6][NdCl4(H2O)2]2Cl3

Preparation and Crystal Structure of (CH₃NH₃)₈[NdCl₆][NdCl₄(H₂0)₂]₂Cl₃ (CH₃NH₃)₈[NdCl₆][NdCl₄ (H₂O)₂]₂Cl₃ is for the first time prepared and investigated by X-ray, single crystal work. It crystallizes in the monoclinic system (space group C2/m, Z = 2) with a = 9.358(5), b = 17.424(9), c = 15.360(8) Å, β = 108.30(4)°. The structure contains besides isolated Cl^? ions distorted [NdCl₆]^3? octahedra and [NdCl₄(H₂O)₂]^? chains.     

Über die Kristallstruktur von (C6H5)3SiSH und (C6H5)3SiSBr und die Darstellung des Iodsulfans (C6H5)3SiSI

The Crystal Structure of (C₆H₅)₃SiSH and (C₆H₅)₃SiSBr and the Preparation of the Iodosulfane (C₆H₅)₃SiSI The preparation of the halogenosulfanes Ph₃SiSBr and Ph₃SiSI from Ph₃SiSH and N-halogenosuccinimide is reported. They are characterized by vibrational spectroscopic measurements. Ph₃SiSBr crystallizes in space group P1 with a = 899.3(8) pm, b = 941.3(7) pm, c = 1 051.4(7) pm, α = 109.88(5)°, β = 99.23(6)°, γ = 96.78(6)° and Z = 2. Ph₃SiSH crystallizes in space group P2₁/c with a = 1 879.4(8), b = 966.3(5), c = 1 845.2(9), β = 107.84(4), Z = 8. The halogenosulfanes decompose in polar solvents by formation of sulphur and triphenylsilanhalide.     

Darstellung und Kristallstruktur der Alkalithiochromate (III), ACr5S8 (A ≙ Cs,Rb und K)

Preparation and Crystal Structure of the Alkali Thiochromates (III), ACr₅S₈ (A ? Cs, Rb und K) The alkali thiochromates (III), ACr₅S₈ (A ? Cs, Rb und K), can be obtained by the reaction of chromium powder with the corresponding alkali metal carbonate in a current of dry hydrogensulfide at about 1320 K. X-ray investigations on single crystals revealed that the compounds crystallize isotypic in the space group C2/m (No. 12), z = 2. Chromium is surrounded by six sulphur atoms in form of an octahedron. These sulphur octahedrons are sharing edges and partly faces, building up a frame with tubes which contain the alkali metal ions in a linear arrangement. Remarkable is the very short cesium-cesium distance of 346 pm, in CsCr₅S₈.     

Über den Einfluß der Substituenten im (R3Si)2(P–Si)R2Cl auf Bildung und Eigenschaften der Hexasila-tetraphosphadantane und deren 31P-NMR-Spektren

The Effect of the Substituents in (R₃Si)₂P–SiR₂Cl on the Formation and the Properties of the Hexasilatetraphospha-adamantanes and their ³¹P-NMR Spectra The thermolysis of (Me₃Si)₂P–SiEt₂Cl 4 at 300°C leads to the silylphosphanes with adamantane structure (Et₂Si)_x(Me₂Si)_6–x (x = 0–6), aside of (Me₃Si)₃P, (Et₂MeSi) (Me₃Si)₂P, (Et₂MeSi)₂(Me₃Si)P and Me₃SiCl, Et₂SiCl, Et₂MeSiCl. Due to the different positions of the Et₂Si-bridges in the adamantane cage the compounds featuring x = 2–4, form isomers. The thermolysis of (Me₃Si)₂P–SiEtMeCl 14 occurs analogously and leads to the adamantanes (EtMeSi)_x (Me₂Si)_6–xP₄ (x = 0–6). The introduction of the SiEtMe group causes the existence of chiralic isomers of the compounds featuring x = 2–6. From (Et₃Si)₂P–SiEt₂Cl 24 (Et₂Si)₆P₄ is obtained. The thermolyses of (Me₃Si)₂P–SiPh₂Cl 25 and [(Me₃Si)P–SiPh₂]₂ do not enable the formation of adamantanes with SiPh₂-bridges. They rather lead to Me- and Ph-substituted trisilylphosphanes. The syntheses of the starting compounds 4, 14, 24 , and 25 are reported. The ³¹P-NMR spectra of silylphosphanes with adamantane structure show, that the linear increase of the ³¹P-chemical shift values as dependent on the rising number of Et groups, which is observed in partially Et-substituted methyltrisilylphosphanes, allows the prediction of the δ³¹P values of the specific P atoms in an adamantane cage, heeding both the position and the direction of the SiEt groups in the particular molecule.     

Über Hexafluoroferrate(III): Cs2TlFeF6, Cs2KFeF6, Rb2KFeF6, Rb2NaFeF6 und Cs2NaFeF6

On Hexafluoroferrates(III): Cs₂TlFeF₆, Cs₂KFeF₆, Rb₂KFeF₆, Rb₂NaFeF₆, and Cs₂NaFeF₆ New prepared are the compounds Cs₂TlFeF₆ (a = 9.21₁ Å), Cs₂KFeF₆ (a = 9.04₁ Å), Rb₂KFeF₆ (a = 8.86₈ Å) and Rb₂NaFeF₆ (a = 8.46 ₄Å) all cubic Elpasolithes as well as Cs₂NaFeF₆ (Cs₂NaCrF₆?type, hexagonal with a = 6.28₁, c = 30.53₂ Å), all colourless. Cs₂KFeF₆ was measured magnetically (70–297,2 K). The spectra of reflection were measured (9000–36000 cm^?1). The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.