Die Kristallstruktur der Verbindung Li6[Si2O7]

Zusammenfassung Die Kristallstruktur von Li₆[Si₂O₇] wird mit Hilfe von Patterson-Projektionen und dreidimensionalen Fourier-Synthesen sowie nach der Methode der kleinsten Quadrate bestimmt. Die Gitterparameter der tetragonalen Elementarzelle (P42₁m-D _2d ³ ) betragen:a=7,71₅;c=4,88 Å. Die Verbindung zählt zu den Sorosilicaten mit isolierten [Si₂O₇]-Gruppen. Die Lithiumionen weisen gegenüber Sauerstoff die Koordinationszahlen 4 und 5 auf. Als mittlere Abstände [Å] wurden ermittelt: Si-O : 1,64 Li-O : 1,95 [4] und 2,18 [5].

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The crystal structure ofLi ₆[Si ₂ O ₇]

The crystal structure of Li₆[Si₂O₇] has been determined by means of Patterson projections, 3-dimensional Fourier syntheses and the least-squares method. The lattice parameters of the tetragonal unit cell (P42₁m-D _2d ³ ) area=7.71₅ andc=4.88 Å. The compound belongs to the sorosilicates having isolated [Si₂O₇]-groups. The coordination numbers of the lithium ions are 4 and 5. The average interatomic distances were found to be: Si-O : 1,64 Å; Li-O : 1.95 [4] and 2.18 [5] Å.

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Die Kristallstruktur der Verbindung Li2ZnGeO4

The crystal structure of dilithiumzine orthogermanate, Li₂ZnGeO₄, has been determined and refined byFourier syntheses and least-squares, using three dimensional single-crystal data. A finalR-value of 5.7% was obtained. The monoclinic unit cell (Pn–C_s ²) with the dimensionsa=6.40,b=5.45,c=5.04 Å and =90.2° contains two formula units Li₂ZnGeO₄. The crystal structure is built up by [GeO₄] tetrahedra, which are linked together by [LiO₄] and [ZnO₄] tetrahedra. The average interatomic distances are found to be: Ge–O=1.77, Li–O=2.01 and Zn–O=1.93 Å.     

Zur Darstellung und Kristallstruktur von CrSO4 · 3 H2O

Preparation and Crystal Structure of CrSO₄ · 3 H₂O Evaporating a solution of Cr²⁺ in dilute sulphuric acid at 70°C light blue crystals of CrSO₄ · 3 H₂O were grown. Its x-ray powder diffraction pattern is quite similar to that of CuSO₄ · 3 H₂O. The crystal structure refinement of CrSO₄ · 3 H₂O (space group Ce, a = 5.7056(8) Å, b = 13.211(2) Å, c = 7.485(1) Å, β = 96.73(1)°, Z = 4) from single crystal data, using the parameters of the copper compound as starting values, results in a final R-value of R = 3.8%. The surrounding of the Cr²⁺ ion can be described as a strongly elongated octahedron. The basal plane of the CrO₆-octahedron consists of three hydrate oxygen atoms and one sulphate oxygen atom. The two more distant axial oxygen atoms also belong to sulphate groups. Thus they are forming chains of alterning CrO₆-octahedra and SO₄-tetrahedra along [110] and [1–10] linked via common corners. These chains are connected via sulphate groups and by bridging hydrogen bonds to a 3-dimensional network.     

Zur Kenntnis von Polymetaarseniten Darstellung und Kristallstruktur von BaAs2O4 · H2O

Concerning Polymetaarsenites. Preparation and Crystal Structure of BaAs₂O₄. H₂O BaAs₂O₄·H₂O was prepared by hydrothermal reaction of BaO with As₂O₃ at a temperatur of 200°C. An X-ray structural analysis demonstrated that the phase contains polymetaarsenite anions [As₄O₈^4?]_n, which adopt vierer single chains in the lattice. The relationship between the conformation of metaarsenite chains and cation size is discussed.     

Die Kristallstruktur der Verbindung Cd2Ge7O16

The crystal structure of Cd₂Ge₇O₁₆ has been determined by means of three-dimensional single-crystal data. A finalR-value of 6.3% was obtained by least squares refinement based on 230 observed reflexions. The tetragonal unit cell with the lattice parametersa=11.31 andc=4.63 Å contains two formula units Cd₂Ge₇O₁₆. The compound is built up by [GeO₄]-tetrahedra and [GeO₆]-octahedra forming a three-dimensional framework with the Cd atoms located in the cavities. The average interatomic distances are found to be: Ge–O=1.74 (tetrahedra), 1.89 (octahedra) and Cd–O=2.36 Å.

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Zur Darstellung und Kristallstruktur der Thiotellurite BaTeS3 · 2 H2O und (NH4)2TeS3

Preparation and Crystal Structure of the Thiotellurites BaTeS₃·2H₂O and (NH₄)₂TeS₃ The new compounds BaTeS₃ · 2 H₂O and (NH₄)₂TeS₃ have been prepared and their structures determined. According to these the anion of the trithiotelluric acid in these compounds represents a distorted trigonal TeS?pyramid. The Te? S-distances are 2.34–2.36 Å. Crystallographic data see ?Inhaltsübersicht”?.     

Darstellung und Kristallstruktur von Na2Mn3O7

Synthesis and Crystal-Structure of Na₂Mn₃O₇ Single crystals of Na₂Mn₃O₇ have been grown hydrothermally applying high oxygen pressure (p = 2 kbar). The new compound cystallizes triclinic; space group P1 ; a = 6.636(6) Å, b = 6.854(6) Å, c = 7.548(6) Å, α = 105.76(6)°, β = 106.86(6)°, γ = 111.60(6)°; Z = 2. The crystal structure has been solved and refined to R = 7.9% and R_w = 6.2% (diffractometer data, 1044 independent reflexions). The crystal structure consists of Mn₃O₇^2? anions with manganese coordinated octahedrally by oxygen. These layered anions are hold together by Na⁺ ions (coordination numbers 5 and 6).     

Darstellung und Kristallstruktur von Rb2Sn3S7 · 2H2O und Rb4Sn2Se6

Preparation and Crystal Structure of Rb₂Sn₃S₇ · 2 H₂O and Rb₄Sn₂Se₆ Rb₂Sn₃S₇ · 2 H₂O has been prepared by hydrothermal reaction of SnS₂ and Rb₂CO₃ in an with H₂S saturated aqueous solution at 190°C. The crystal lattice contains chain anions [Sn₃S₇^2?] which display both SnS₄ tetrahedra and SnS₆ octahedra. Methanolothermal reaction of SnCl₂ with Se and Rb₂CO₃ at 145°C leads to the formation of Rb₄Sn₂Se₆ which contains edge-bridged bitetrahedral [Sn₂Se₆]^4? anions.     

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.     

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.     

Die Kristallstruktur der Verbindung Li3Zn0,5GeO4

The crystal structure of the compound Li₃Zn_0.5GeO₄ has been determined and refined by means of three-dimensionalFourier syntheses and least squares. Li₃Zn_0.5GeO₄ crystallizes orthorhombic with space groupD _2h ¹⁶ -Pmnb (No. 62) and the lattice parametersa=6.29,b=10.74 andc=5.17 Å. The crystal structure consists of isolated [GeO₄] tetrahedra, which are linked together by [(Li,Zn)O₄] tetrahedra analogous to Li₃PO₄(h). An additional eight-fold position is partly occupied by two lithium atoms. The occupancy of this position may vary according to the observed range of composition, which lies between Li_3.8Zn_0.1GeO₄ and Li_2.6Zn_0.7GeO₄.

     

Darstellung und Kristallstruktur von Rb4Br2O und Rb6Br4O

Syntheses and Crystal Structures of Rb₄Br₂O and Rb₆Br₄O In the quasi‐binary system RbBr/Rb₂O, the addition compounds Rb₄Br₂O and Rb₆Br₄O are obtained by solid state reaction of the boundary components RbBr and Rb₂O. Crystals of red‐orange Rb₄Br₂O as well as of orange Rb₆Br₄O decompose immediately when exposed to air. Rb₄Br₂O (Pearson code tI14, I4/mmm, a = 544.4(6) pm, c = 1725(2) pm, Z = 2, 175 symmetry independent reflections with I_o > 2σ(I), R₁= 0.0618) crystallizes in the anti K₂NiF₄ structure type; Rb₆Br₄O (Pearson code hR22, R3c, a = 1307.8(3) pm, c = 1646.6(5) pm, Z = 6, 630 symmetry independent reflections with I_o > 2σ(I), R₁ = 0.0759) in the anti K₄CdCl₆ structure type. Both structures contain characteristic ORb₆‐octahedra and can be understood as expanded perovskites, following the general systematics of alkaline metal oxide halides.     

Darstellung und Kristallstruktur von Cs8P8O24 · 8H2O

Synthesis and Crystal Structure of Cs₈P₈O₂₄ · 8H₂O Cs₈P₈O₂₄ · 8H₂O was obtained from Na₈P₈O₂₄ · 6H₂O by cation exchange. Crystal growth was achieved by applying gel techniques (agar agar). The crystal structure (P1 ; a = 766.6(8); b = 1 156.9(9); c = 1 163.4(9) pm; α = 100,2(1)°; β = 106.5(2)°; γ = 92.2(1)°; Z = 1; 4 099 unique diffractometer data; R = 0.051; R(w) = 0.037) contains cyclo-octaphosphate anions with point symmetry C_2h. The cesium atoms are coordinated irregularily by eight and ten oxygen atoms, respectively. The threedimensional linkage of the P₈O₂₄^8?-rings is established via bonds to cesium atoms and hydrogen bonds Provided by H₂O molecules.     

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 Tieftemperaturmodifikationen von Ag6Si2O7 und Ag6Ge2O7 – Darstellung,Kristallstruktur und Vergleich der Ag?Ag-Abstände

On the Low Temperature Modifications of Ag₆Si₂O₇ and Ag₆Ge₂O₇ – Synthesis, Crystal Structure, and Comparison of Ag? Ag Distances For the first time, single crystals of Ag₆Si₂O₇ and Ag₆Ge₂O₇ have been obtained by solid state reactions of the binary oxides at temperatures of 350°C while applying oxygen pressures of 700 bar. According to the results of X-ray crystal structure determinations both compounds crystallize isostructural in P2₁ (Ag₆Si₂O₇: a = 5.3043(5) Å, b = 9.7533(7) Å, c = 15.9283(13) Å, β = 91.165(8)°, 3881 independent reflections, R1 = 3.3%, wR2 = 7.2%; Ag₆Ge₂O₇: a = 5.3713(4) Å, b = 9.9835(8) Å, c = 16.2249(14) Å, β = 90.904(8)°, 2111 independent reflections, R1 = 4.3%, wR2 = 6.0%, Z = 4). The crystal structures contain two independent M₂O₇^6? anions, one in a staggered, and the other in an ecliptic conformation. The cationic partial structure may be described as a distorted bcc arrangement of Ag⁺ and M⁴⁺. Comparison of the structures with respect to the Ag? Ag separations reveals the latter to be probably due to intrinsic d¹⁰–d¹⁰ bonding interactions as far as the range of 2.89 Å to 3.25 Å is considered.     

Darstellung und Kristallstruktur von Ag2O3

Preparation and Crystal Structure of Ag₂O₃ The novel compound Ag₂O₃ was obtained by anodic oxidation of aqueous solutions of AgBF₄, AgClO₄, and AgPF₆. According to single crystal investigations Ag₂O₃ belongs to the orthorhombic crystal system (Fdd2; a = 1286.9(1), b = 1049.0(1), c = 366.38(5) pm; Z = 8; 309 independent diffractometer data; R = 1.2%). Ag₂O₃ is isostructural to Au₂O₃ and contains silver square-planarly coordinated by oxygen. The AgO₄ groups are connected via common vertices forming a 3-d framework.     

Zur Darstellung und Kristallstruktur von Tl2O

The preparation of Tl₂O and its crystal structure is discussed. By FOURIER methods for a monoclinic unit cell(a_M = 6.08₂, b_M = 3.52₀, c_M = 13.2₄ Å, β = 108.2°, Z = 4, space group C_2h³) the determined atomic parameters can be transformed into the trigonal system by the assumption of special oxygen positions (space group No. 166–R3 m). Correspondingly the Tl₂O crystal structure may be described as a threefold polytype form of the anti CdJ₂ type (a_H = 3,51₆ c_H = 37.8₄ Å; c/a = 10.76, Z = 6, mol. vol. = 40.7 cm³; d_x = 10.44, d_pyk = 10.4 g m^?).     

Darstellung und Kristallstruktur der bekannten Zintl‐Phasen Cs3Sb7 und Cs4Sb2

Synthesis and Crystal Structure of the known Zintl Phases Cs₃Sb₇ and Cs₄Sb₂ Cs₃Sb₇ and Cs₄Sb₂ were synthesized from the elements and their crystal structures were determined on the basis of single crystal x‐ray data. Cs₃Sb₇ crystallizes in the monoclinic system with space group P2₁/c (a = 1605.7(1) pm, b = 1571.1(1) pm, c = 2793.9(2) pm, β = 96.300(2)°, Z = 16) and contains anions Sb₇^3–. In the structure of Cs₄Sb₂ (orthorhombic, space group Pnma, a = 1598.5(3) pm, b = 631.9(2) pm, c = 1099.5(2) pm, Z = 4) dumbbells Sb₂^4– are present.