Synthese und Kristallstrukturen von IMalnBr4 und NaInI4

Inhaltsübersicht. Einkristalle von NaInBr₄ und NaInI₄ erhält man aus Gemengen der binären Komponenten durch langsames Abkühlen der Schmelze. NaInBr₄ gehört zum NaAlCl₄-Typ: Orthorhombisch, P2₁2₁2₁, Z = 4; a = 1108,1(1); b = 1050,7(1); c = 676,1(1) pm. NaInI₄ ist isotyp mit LiAlCl₄: Monoklin, P2₁/c, Z = 4; a = 852,1(2); b = 766,1(2); c = 1558,3(3) pm; β = 92,65(2)°. In beiden Strukturen treten annähernd tetraedrische Baugruppen [InX₄]^– (X = Br, I) auf. Die Koordinationszahl von Na⁺ ist C.N. = 6 (NaInI₄; leicht verzerrt oktaedrisch) bzw. C.N. = 6+1+1 (NaInBr₄; verzerrtes, doppelt bekapptes Prisma). Synthesis and Crystal Structures of NaInBr₄ and NaInI₄ Single crystals of NaInBr₄ and NaInI₄ are obtained from mixtures of the binary components by slow cooling of the melts. NaInBr₄ belongs to the NaAlCl₄ type of structure: Ortho-rhombic, P2₁2₁2₁, Z = 4, a = 1108.1(1), b = 1050.7(1), c = 676.1(1) pm. NaInI₄ is isotypic with LiAlCl₄: Monoclmic, P2₁/c, Z = 4, a = 852.1(2), b = 766.1(2), c = 1558.3(3) pm, β = 92.65(2)°. Almost tetrahedral polyhedra [InX₄]^– (X = Br, I) are characteristic for both structures. The coordination number of Na⁺ is C.N. = 6 (NaInI₄; slightly distorted octahedron) and C.N. = 6+1+1 (NaInBr₄; distorted bicapped trigonal prism), respectively.     

Struktur und Eigenschaften von TlZnPO4 und TlZnAsO4

Structure and Properties of TlZnPO₄ and TlZnAsO₄ TlZnPO₄ and TlZnAsO₄ have polymorphic behavior with two phase transitions (TlZnPO₄: 263°C, 450°C; TlZnAsO₄: 562°C, 752°C) between room temperature and the congruent melting point at 1 090°C for TlZnPO₄ and 930°C for TlZnAsO₄. X-ray diffraction powder patterns have shown, that the compounds are isotypic and crystallize in the monoclinic system with the lattice constants a = 882.8(2), b = 546.2(1), c = 872.9(1) pm, β = 90.61(2)° for TlZnPO₄, a = 895.4(1), b = 562.3(1), c = 892.8(1) pm, β = 91.08(2)° for TlZnAsO₄, Z = 4, space group P2₁. TlZnPO₄ and TlZnAsO₄ belong to the „stuffed derivatives”︁ of the Icmm structure type with a [ZnXO₄]⁻ network of corner linked alternating ZnO₄ and XO₄ tetrahedra (X = P, As) with channels of six-membered rings in the direction of the c axis. These cavities contain the Tl cations. The results of ³¹P MAS-NMR measurement of TlZnPO₄ may be correlated with its structure. The Tl⁺ ionic conductivity at 300°C reaches only values of 4.4 × 10⁻⁸ Ω⁻¹ cm⁻¹ for TlZnPO₄ and 4.5 × 10⁻⁸ Ω⁻¹ cm⁻¹ for TlZnAsO₄.     

Zur Darstellung und Kristallstruktur von RbTlF4 und CsTlF4

Preparation and Crystal Structure of RbTlF₄ and CsTlF₄ RbTlF₄ and CsTlF₄ were synthesized by heating equivalent mixtures of alkaline chlorides or carbonates and Tl₂O₃ under a current of fluorine at 450–500°C. The crystal structure of RbTlF₄ has been determined by single crystal X-ray diffraction methods. The unit cell is orthorhombic with a = 8.252, b = 8.359, c = 6.244 Å (Z = 4); space group: C?Pb2₁a. CsTlF₄ and Tl^ITl^IIIF₄ (“TlF₂”) are isostructural with RbTlF₄. The structure contains layers of 2-dimensionally corner-linked distorted [TlF_4/2F₂]-octahedra, which are connected by rubidium ions.     

Synthese und Kristallstrukturen der Tetrachlorozinkate SrZnCl4 und BaZnCl4

Synthesis and Crystal Structures of the Tetrachlorozincates SrZnCl₄ and BaZnCl₄ The tetrachlorozincates SrZnCl₄ and BaZnCl₄ are obtained from the respective binary chlorides at 550 °C in silica ampoules. SrZnCl₄ (tetragonal, I4₁/a, Z = 4, a = 650.40(7), c = 1437.0(2) pm) crystallizes with the scheelite type of structure, BaZnCl₄ (orthorhombic, Pnna, Z = 4, a = 724.15(6), b = 986.2(2), c = 947.71(8) pm) belongs to the GaCl₂ type of structure. The coordination polyhedra of the cations are the same in both compounds: Sr²⁺ and Ba²⁺ are surrounded by eight Cl^– (trigon‐dodecahedron), Zn²⁺ is tetrahedrally coordinated. For both compounds no phase transitions could be detected between 140 and 620 K.     

Zintlphasen mit isolierten SiAs4- bzw. GeAs4-Anionen: Darstellung und Struktur von Ba4SiAs4 und Ba4GeAs4 sowie Sr4SiAs4 und Sr4GeAs4

Die erstmals dargestellten isotypen Verbindungen Ba₄SiAs₄, Ba₄GeAs₄, Sr₄SiAs₄ und Sr₄GeAs₄ kristallisieren kubisch, Raumgruppe P4 3n, mit 8 Formeleinheiten in der Elementarzelle: In den Strukturen liegen isolierte, d.h. nur von Ba-Ionen umgebene SiAs - bzw. GeAs -Tetraeder vor. Die Verbindungen sind die bisher eindrucksvollsten Beispiele für Zintlphasen mit komplexen Anionen. Zintl Phases with Isolated SiAs₄ or GeAs₄ Anions: Preparation and Structure of Ba₄SiAs₄, Ba₄GeAs₄, Sr₄SiAs₄, and Sr₄GeAs₄ The new compounds Ba₄SiAs₄, Ba₄GeAs₄, Sr₄SiAs₄, and Sr₄GeAs₄ have been prepared and their structures determined. They crystallize in the cubic system, P4 3n, with axes: data see “Inhaltsübersicht”. There are isolated SiAs or GeAs tetrahedra in the structures. The compounds can be interpreted as Zintl phases with complex anions.     

D-Glucosaminhydrochlorid und 4 Derivate

Ohne Zusammenfassung     

Synthese und chemie von 4R-silacyclohexa-2,5-dienen und 4R-silacyclohexa-2,4-dienen

The 1(Z),4(Z)-1,5-dilithium-3R-3-methoxypenta-1,4-dienes, available by cleavage of 1,1-di-n-butyl-4R-4-methoxy-1-stannacyclohexane-2,5-dienes with n-BuLi in ether, react with dichlorosilanes (R′R″ SiCl₂; R′, R″ = H, alkyl, aryl, alkoxy) to give 1R′,1R″,4R-4-methoxy-1-silacyclohexa-2,5-dienes.Claevage of the ether group with BBr₃, BCl₃ or PCl₃ gives 6-chloro(bromo)-1-silacyclohexa-2,4-dienes or 1,5-dichloro-1-silacyclohexane-2,4-dienes, respectively.Ether cleavage of 4R-4-methoxy-1-silacyclohexa-2,5-dienes with sodium results in the formation of 4R-1-silacyclohexadienyl anions, which can be hydrolyzed to give 1-silacyclohexa-2,4-dienes which reach further with trichloromethylsilane to give 6-trimethylsilyl-1-silacyclohexa-2,4-dienes.Phase transfer-catalyzed conversion of 1-chlorosilacyclohexadienes into the fluoro derivatives as well as further substitution reactions of 1-chlorosilacyclohexadienes are described.The ¹H NMR, ¹³C NMR, IR and mass spectra of the silacyclohexadienes are discussed.     

Phosphono- und Phosphinoameisensäurederivate via Alkoxycarbonylphosphon- und -phosphinsäuretrimethylsilylester

Phosphono-Phosphinoformic Acid Derivatives via Alkoxycarbonylphosphono and Phosphino Acid Trimethylsilylesters The sodium salts, the chlorides and amides of the phosphono- and phosphinoformic acid esters are easily prepared under various conditions from the corresponding alkoxycarbonyl-P-trimethylsilylesters. The alkoxycarbonyl group of the synthesized compounds it not Stable in acidic solution because of an autocatalytic decarboxylation. Under these conditions the chlorides and amides are hydrolyzed too. The Structure of the compounds prepared are discussed by means of their n.m.r. data.     

Halogenidsulfate des Gadoliniums: Synthese und Kristallstruktur von GdClSO4 und GdFSO4

Halide Sulfates of Gadolinium: Synthesis and Crystal Structure of GdClSO₄ and GdFSO₄ Single crystals of GdClSO₄ are obtained from the reaction of Gd₂(SO₄)₃ and GdCl₃ in silica ampoules. In the monoclinic compound (P2₁/c, Z = 4, a = 943.7(1), 657.59(8), 680.05(9) pm, β = 104.87(2)?, R_all = 0.0352) Gd³⁺ is surrounded by five sulfate groups and three chloride ligands. One of the sulfate groups acts as a bidentate ligand so that the coordination number of Gd³⁺ is nine. The reaction of Gd₂(SO₄)₃ with LiF in sealed gold ampoules yields colorless transparent single crystals of GdFSO₄. The compound crystallizes orthorhombic (Pnma, Z = 4, a = 843.6(1), b = 701.76(8), c = 643.38(7) pm, R_all = 0.0207) and contains eight‐coordinate Gd³⁺ ions. The ligands are six oxygen atoms of five sulfate groups and two fluoride ions.     

Schwingungsspektren von As4S4 und As4Se4

Vibrational Spectra of As₄S₄ and As₄Se₄ The vibrational spectra of solid α- and β-As₄S₄ and the Raman spectrum of molten As₄S₄ have been recorded. The assignments of the frequencies are proposed mainly based on polarization data. The Raman melt spectra suggest that As₄S₄ molecules (symmetry D_2d) are retained in the molten state. A partial decomposition of the melt by prolonged laser irradiation was observed. The Raman spectrum of solid As₄Se₄ is presented and the frequencies are tentatively assigned to an As₄Se₄ molecule of the cradle type, possessing D_2d symmetry.     

Synthese,Eigenschaften und Struktur von LiAuI4 und KAuI4 mit einer Diskussion der kristallchemischen Verwandtschaft zwischen den Halogenoauraten RbAuCl4, AgAuCl4, RbAuBr4 und LiAuI4

Synthesis, Properties, and Structure of LiAuI₄ and KAuI₄ with a Discussion of the Crystal Chemical Relationship between the Halogenoaurates RbAuCl₄, AgAuCl₄, RbAuBr₄ and LiAuI₄ The alkalimetal iodo aurates(III) MAuI₄ (M ? Li, K) are obtained in form of single crystals from MI, Au and I₂ in a sealed glass ampoule by heating to 550°C and slow cooling to 300°C. KAuI₄ crystallizes in the monoclinic space group P2₁/c with a = 968.6(4); b = 704.5(2), c = 1393.2(7) pm; β = 100.95(2)° and Z = 4. The crystal structure is built up from square planar AuI₄^? anions and K⁺ cations. The cations are coordinated by eight I atoms of neighbouring AuI₄^? anions with distances K? I between 350.0 and 369.6 pm. At 100°C KAuI₄ is reduced to form K₃Au₃I₈, which at 180°C decomposes to KI, Au and I₂ LiAuI₄ forms black, moisture sensitive needles, decomposing in the absence of iodine at 20°C to LiI, Au and I₂. It crystallizes in a variant of the RbAuBr₄ type structure with the space group P2₁/a and a = 1511.7(4); b = 433.9(4); c = 710.0(2) pm; β = 121.50(2)°; Z = 2. The crystal chemical relationship between the structures of RbAuCl₄, RbAuBr₄, AgAuCl₄ and LiAuI₄ is discussed.     

Zur Kenntnis von BaTiVO4 und SrTiVO4

On BaTiVO₄ and SrTiVO₄ BaTiVO₄ and SrTiVO₄ were prepared in closed systems by solid state reactions. They crystallize with orthorhombic symmetry (BaTiVO₄: space group D-Pmnb; a = 5.889; b = 7.889; c ?10.397 Å; Z = 4; SrTiVO₄: space group D-P2¹,2¹,2¹,2¹; a = 5.855; b = 7.572; c = 10.012 Å; Z = 4) and belong to β-K₂SO₄-type. The ordered occupation of point positions by Ba²⁺ and Tl⁺ as well as the decrease in symmetry of SrTiVO₄ are discussed.     

Züchtung und Untersuchung von Einkristallen der Verbindungen CuCrZrSe4 und CuCrSnSe4

Preparation and Characterization of CuCrZrSe₄ and CuCrSnSe₄ Single Crystals Single crystals of the compounds CuCrZrSe₄ and CuCrSnSe₄ were grown by chemical transport using mixtures of AlCl₃/I₂ as transporting agents. Characterization of the crystals was done by X-ray methods. The compounds are normal spinels, the space group is Fd3m. The results of least squares refinement using single crystal X-ray data are reported.     

Die Bildungsenthalpie von NbBr4 und Nbl4

Enthalpy of Formation of NbBr₄ and NbI₄ . The enthalpy of formation of NbBr₄ and NbI₄ has been determined by adiabatic calorimetry as ?120.0 kcal/Mole and ?63.04 kcal/Mole.     

Darstellung und Struktur der Verbindungen Ba2SiTe4 und Ba2SiSe4

On Chalcogenidosilicates: Ba₂SiTe₄ and Ba₂SiSe₄ The new compounds Ba₂SiSe₄ and Ba₂SiTe₄ crystallize in the monoclinic system, space group: P2₁/m (No. 11) with the lattice constants s. “Inhaltsübersicht”. Both compounds are isotypic to the Sr₂GeS₄ structure. Ba₂SiTe₄ is the first o-telluridosilicate with discrete SiTe₄^4? anions.     

Alkalikationen-Spezifität und Träger-Eigenschaften der Antibiotica Nigericin und Monensin

It is shown by means of IR. spectroscopic methods that nigericin and monensin have a cyclic conformation similar to that of their silver salts. Complex formation constants with sodium and potassium ions follow the selectivity order determined by EMF. measurements on liquid membranes: nigericin: K⁺ > Rb⁺ > Na⁺ > Cs⁺ > Li⁺; monensin: Na⁺ > K⁺ > Li⁺ > Rb⁺ > Cs⁺. Transport experiments show that nigericin and monensin facilitate the diffusion of potassiumions across model membranes, although in electrolytic transport experiments the permeability is not affected.     

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.