Darstellung und Struktur von K3(SH)TeS3

Preparation and Crystal Structure of K₃(SH)TeS₃ K₃(SH)TeS₃ has been prepared and structurally characterized. It crystallizes cubic with a = 1270(2) pm, space group 143m. The SH- Ions are surrounded by an octahedron of K⁺ ions. The TeS₃^2?. anions form flat trigonal pyramids with Te? S distances of 234.8(2) pm.     

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”?.     

Die Kristallstruktur von K2S3 und K2Se3

The Crystal Structure of K₂S₃ and K₂Se₃ Well formed crystals of K₂S₃ and K₂Se₃ were obtained by reaction of the elements in liquid ammonia at 500 bar and 150°C. The substances are both orthorhombic, space group Cmc2₁. Cell constants are: The structure contains S₃^2?(Se₃^2?) polyanions, with S? S? S(Se? Se? Se) angles of 105.4(102.5)°. The S? S(Se? Se) distance is 2.083(2.383) Å.     

Synthese und Kristallstrukturen von (PPh4)2[TeS3] · 2 CH3CN und (PPh4)2[Te(S5)2]

Synthesis and Crystal Structures of (PPh₄)₂[TeS₃] · 2 CH₃CN and (PPh₄)₂[Te(S₅)₂] (PPh₄)₂[TeS₃] · 2 CH₃CN was obtained by the reaction of PPh₄Cl, Na₂S₄ and Te in acetonitrile. With sulfur it reacts yielding (PPh₄)₂[Te(S₅)₂]. The crystal structures of both products were determined by X-ray diffraction. (PPh₄)₂[TeS₃] · 2 CH₃CN: triclinic, space group P1 , Z = 2, R = 0.041 for 4 629 reflexions; it contains trigonal-pyramidal [TeS₃]^2? ions with an average Te? S bond length of 233 pm. (PPh₃)₂[Te(S₅)₂]: monoclinic, P2₁/n, Z = 2, R = 0.037 for 2 341 reflexions. In the [Te(S₅)₂]^2? ion the tellurium atom has a nearly square coordination by four S atoms. Along with the Te atoms each of the two S₅ groups forms a ring with chair conformation.     

Zur Kenntnis von K2GeO3

On K₂GeO₃ Single crystals of K₂GeO₃ have been prepared by heating K₂O and GeO₂ (K:Ge = 3.0:1.0; Ag-cylinder, 10 d, 700–800°C). The structure has been refined. K₂GeO₃: a = 2302.5(3), b = 3286.3(5), c = 545.2(1) pm; Pbca; R = 13.83%; R_w = 9.60% (different parameters see text). The structure of K₂GeO₃ will be discussed. The Effective Coordination Numbers, ECoN, the Mean Fictive Ionic Radii, MEFIR, and the Madelung Part of Lattic Energy, MAPLE, are calculated.     

K3FeSe3 und K3Fe2Se4, zwei neue Verbindungen im System K/Fe/Se

K₃FeSe₃ and K₃Fe₂Se₄, Two New Compounds in the System K/Fe/Se The two selenides K₃FeSe₃ and K₃Fe₂Se₄ were synthesised by fusion reactions of potassium carbonate with iron and selenium in a stream of hydrogen charged with selenium at 695 °C and 710–730 °C, respectively. The crystal structures were determined by single‐crystal X‐ray diffractometer data. The atomic arrangement of K₃FeSe₃ is characterised by edge sharing [Fe₂Se₆] double tetrahedra separated by potassium ions (space group P2₁/c, Z = 4). The characteristic structural unit of the mixed‐valent compound K₃Fe₂Se₄ is a zig‐zag chain of edge‐sharing, iron‐centred selenium tetrahedra, again separated by potassium ions (space group Pnma, Z = 4).     

Zum System K2O/PbO. Zur Kenntnis von K2Pb2O3

On the System K₂O/PbO: The Crystal Structure of K₂Pb₂O₃ Orange-coloured single crystals of K₂Pb₂O₃ crystallize by means of 4-circle-Diffractometer data (237 of 238 possible hkl, R = 5.9₉%, MoKα) cubic with a = 8.41₉ Å, Z = 4, in space group I2₁3?T⁵, parameter see text. We find a superstructure of the perovskite type of structure, where, concerning the formula KPbO_3/2, half of the O^2? ions are omitted systematically, without loosing the 3-Dimensional arrangement of order. Pb²⁺ is surrounded by 3 K⁺ by 6 O^2? and O^2? by 2 Pb²⁺ and 4 K⁺. The Madelung Part of the Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, are calculated and discussed.     

K2CO3-Na2CO3-Li2CO3-H2O四元体系288K的相平衡

水盐体系;碳酸盐;溶解度;盐湖卤水;K2CO3-Na2CO3-Li2CO3-H2O四元体系288K的相平衡     

Kaliumamidotrioxogermanate(IV) – Wasserstoff-Brückenbindungen in K3GeO3NH2 und K3GeO3NH2 · KNH2

Potassium Amido Trioxo Germanates(IV) – Hydrogen Bridge Bonds in K₃GeO₃NH₂ and K₃GeO₃NH₂ · KNH₂ Colorless crystals of K₃GeO₃NH₂ and of K₃GeO₃NH₂ · KNH₂ were obtained by the reaction of KNH₂ with GeO₂ in supercritical ammonia at 450°C and p = 6 kbar in high-pressure autoclaves within 15 resp. 5 days. The crystal structures of both compounds were solved by X-ray single crystal methods. K₃GeO₃NH₂: P1 , a = 6.390(1) Å, b = 6.684(1) Å, c = 7.206(1) Å, α = 96.47(1)°, β = 101.66(1)°, γ = 91.66(1)°, Z = 2, R/R_w = 0.020/0.022, N(I) ≥ 2σ(I) = 3023, N(Var.) = 82 K₃GeO₃NH₂ · KNH₂: P2₁/c, a = 10.982(6) Å, b = 6.429(1) Å, c = 12.256(8) Å, β = 106.12(1)°, Z = 4, R/R_w = 0.022/0.029, N(F) ≥ 3σ(F) = 1745, N(Var.) = 107. In K₃GeO₃NH₂ tetrahedral ions GeO₃NH₂^3? are connected to chains by N? H …? O bridge bonds with 2.18 Å ≤ d(H …? O) ≤ 2.40 Å for d(N? H) ? 1.0 Å and by potassium ions while in K₃GeO₃NH₂ · KNH₂ bridge bonds between NH₂ groups of GeO₃NH₂^3? and NH₂^? ions as acceptors occur with 2.41 Å ≤ d((N? )H …? NH₂^?) ≤ 2.61 Å for d(N? H) ? 1.0 Å.     

3-Carboxylate-Substituted Isoindolinones in K2CO3-Catalyzed Michael Reactions

Activated 3-substituted isoindolinones have proved to be efficient nucleophiles in K₂CO₃-catalyzed Michael reactions of several types of electron-deficient olefins. Moreover, tricyclic pyrrolizidines have been conveniently synthesized via a modification of the described general protocol as a consequence of a cascade Michael/cyclization reaction of unsaturated aldehydes.     

Three new phases in the K/Cu/Th/S system: KCuThS3, K2Cu2ThS4, and K3Cu3Th2S7

Synthetic exploration of K/Cu/Th/S quaternary phase space has yielded three new compounds: KCuThS3 (I), K2Cu2ThS4 (II), and K3Cu3Th2S7 (III). All three phases are semiconductors with optical band gaps of 2.95, 2.17, and 2.49 eV(I-III). Compound I crystallizes in the orthorhombic space group Cmcm with a = 4.076(1) A, b = 13.864(4) A, and c = 10.541(3) A. Compound II crystallizes in the monoclinic space group C2/m with a = 14.522(1) A, b = 4.026(3) A, and c = 7.566(6) A; beta = 109.949(1) degrees . Compound III crystallizes in orthorhombic space group Pbcn with a = 4.051(2) A, b = 14.023(8) A, and c = 24.633(13) A. The compounds are all layered materials, with each layer composed of threads of edge-sharing ThS6 octahedra bridged by CuS4 tetrahedral threads of varying dimension. The layers are separated by well-ordered potassium ions. The relatively wide range of optical band gaps is attributed to the extent of the CuS4 motifs. As the dimension of the CuS4 chains increases, band gaps decrease in the series. All materials were characterized by single-crystal X-ray diffraction, microprobe chemical analysis, and diffuse reflectance spectroscopy (NIR-UV).     

Oxide eines neuen Formeltyps: Zur Kenntnis von K3Ni2O4 und K3Pt2O4

Oxides of a New Type of Formula: On the Knowledge of K₃Ni₂O₄ and K₃Pt₂O₄ K₃Ni₃O₄, greyblack single crystals, obtained by heating K₂O and NaNiO₂ [K:Ni = 2:1, 500°C, 7d, Ag-cylinders], crystallizes orthorhombic with a = 6.04₄, b = 9.04₉, c = 10.56₇ Å, Z = 4, space group Cmcm (d_rö = 3.43, d_pyk = 3.32 g · cm^?3). Due to four cycle diffractometer data (374 hkl, MoKα, R = 8.6percnt;) a new type of structure is found with wavebands of [NiO_4/2] \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^{\rm 1} $\end{document} exhibits the C.N. 6, \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^{\rm 2} $\end{document} the C.N. 4. Effective Coordination Numbers, ECoN, calculated by means of Mean Fictive Ionic Radii, MEFIR, the Madelung Part of Lattice Energy, MAPLE and the magnetic properties are discussed. K₃Pt₂O₄, black single crystals with metallic lustre, obtained by heating KO_x (x = 1.55 or 1.88) and Pt (powder) [K:Pt = 4:1,1000°C, lh, 600°C, 2d, Pt-capsules] is isotypic to K₃Ni₂O₄ (four cycle diffractometer data: 458 hkl, MoKα, R = 12percnt;). Cellparameters are a = 6.15, b = 9.27, c = 11.51 Å (single crystal data), d_rö = 5.79 and d_pyk = 5.77 g · cm^?3.     

Oxydationsprodukte intermetallischer Phasen. III. Tieftemperaturformen von K2Sn2O3 und Rb2Sn2O3 und eine Notiz über K2Ge2O3

Oxidation Products of Intermetallic Compounds. III. Low Temperature Forms of K₂Sn₂O₃ and Rb₂Sn₂O₃ and a Notice about K₂Ge₂O₃ By controlled oxidation of KSn (at 320°C) and RbSn (at 410°C) with O₂ the hitherto unknown low temperature forms of K₂Sn₂O₃ (a = 8.4100(8) Å) and Rb₂Sn₂O₃ (a = 8.6368(8) Å) are obtained, which are isotopic with cubic K₂Pb₂O₃. Oxidation at higher temperatures (at 510–5207°C) leads to the well-known HT-forms. The Madelung Part of Lattic Energie, MAPLE, is calculated for both compounds. K₂Pb₂O₃, Rb₂Pb₂O₃, Cs₂Pb₂O₃, and Cs₂Sn₂O₃ have been prepared too by oxidation of KPb, RbPb, CsPb, and CsSn. Oxidation of KGe (at 400°C) leads to the first oxogermanate(II), K₂Ge₂O₃ (cubic a = 8.339(1) Å, isotypic with K₂Pb₂O₃) together with K₆Ge₂O₇.