Synthese und Kristallstruktur von BaVo2,5

Single crystals of BaVO_2,5 were prepared by high temperature LASER-technique under a hydrogen atmosphere. The X-ray investigation leads to a trigonal symmetry (a=571.8;c=1161.3 pm, space group C _3v ¹ -P3m 1). BaVO_2,5 consists of a closest sphere packing of oxygen with a sequence of cubic and hexagonal layers of the type ... ccchh ... The consequences in respect to the coordination of Ba²⁺ and V³⁺ are discussed.

     

Analyse von Schichten und Schichtsystemen mit hochenergetischen Ionenstrahlen

Summary The utility of energetic ion beams for thin film analysis is reviewed briefly. The different methods for analysis are based on the different interactions of the fast ions with atomic nuclei and electrons of the solid state samples to be analysed. These interactions include not only ion scattering, but also emission of x-rays and nuclear reactions. Quantitative chemical analysis with good depth resolution by Rutherford-backscattering analysis (RBS) is demonstrated for the suicide formation at the interface between Si and metal. Particle induced x-ray emission (PIXE) can be used for the detection of small amounts of impurities (atomic number Z 6). In addition, light elements can be detected within a heavy matrix using ion beams for nuclear reaction analysis (NRA). The different ion beam methods are compared and their advantages are discussed with respect to different analytical problems. In addition, channeling experiments on epitaxial superlattices are presented which allow the determination of the strain individual interfaces.     

Komplexierung von Gold mit N,N-Dialkyl-N′-benzoylthioharnstoffen: Die Kristallstruktur von N,N-Diethyl-N′-benzoylthioureatogold(I)-chlorid

Complex Formation of Gold with N,N-Dialkyl-N′-benzoylthioureas: The Crystal Structure of N,N-0Diethyl-N′-benzoylthioureatogold(I) Chloride N,N-Diethyl-N′-benzoylthioureatogold(I) chloride AuCiS₁₂H₁₆N₂O crystallizes in the monoclinic space group P2₁/c. The cell parameters are a = 18.407(4), b = 5.456(1) and c = 196.322(3) Å, β = 113.6/8(1)°. The structure was solved with direct techniques and refined to final R-value of 5.92%. Gold(I) forms a monodentately sulfur-coordinated complex with the ligand N,N-Diethyl-N′-benzoylthiourea. The coordination sphere around Au(I) shows a nearly linear arrangement of sulfur and chloride.     

Komplexierung von Gold mit N,N-Dialkyl-N′-benzoythioharnstoffen: Die Kristallstruktur von N,N-Diethyl-N′-benzoylformamidin tetrachloroaurat (III)

Complex Formation of Gold with N,N-Dialkyl-N′-benzoylthioureas: The Crystal Structure of N,N-Diethyl-N′-benzoylformamidin-tetrachloroaurate(III) N,N-Diethyl-N′-benzoylformamidin-tetrachloroaurate(III) AuCl₄C₁₂H₁₇N₂O crystallizes in the monoclinic space group P2₁/c. The cell parameters are a = 7.764(2), b = 14.473(4) and c = 16. 105(9) Å β = 100.75(4) ⁰. The structure was solved with direct methods and refined to a final R-value of 3.38%.     

Synthesen überbrückter Bischinonmethide mit doppelter Acylketenaminal-Struktur

Syntheses of Bridged Bisquinonemethides with Double Acylketeneaminal Structure Starting with 1 , the synthesis of bis(tert-butyl)ester 2 is described. Some reactions including methylation of 2 to give 3 and 4 , ( 4 → 5 ) and deprotonation of 5 to 6 are reported. Possible structures of deprotonation products are discussed, based on NMR results.     

Fe4Si2Sn7O16: Eine Kombination von FeSn6-Oktaedern mit Schichten von (Fe3Sn)O6-Oktaedern; Präparation,Eigenschaften und Kristallstruktur [1]

Fe₄Si₂Sn₇O₁₆: A Combination of FeSn₆-Octahedra with Layers of (Fe₃Sn)O₆-Octahedra; Preparation, Properties, and Crystal Structure Fe₄Si₂Sn₇O₁₆ has been prepared by a solid state reaction at 900 °C from a mixture of Fe₂O₃, SnO₂, Sn, and Si. The compound is a paramagnetic semiconductor. Results of Mössbauer and suszeptibility measurements as well as bond length-bond strength calculations lead to the possible ionic formulation Fe₄²⁺Si₂⁴⁺Sn₁²⁺Sn₁⁴⁺O₁₆^2–. The compound crystallizes in the trigonal space group P3m1 (no. 164), with one formula unit per cell. Lattice parameters obtained by powder measurements are: a = 6.8243(6) Å, c = 9.1404(6) Å, γ = 120°, V = 368.6(1) ų. The structure consists of layers of edge linked oxygen octehedra exactly centered by Sn and Fe in the ratio 1 : 3. Three plains of isolated SiO₄ tetrahedra, FeSn₆ octahedra and again SiO₄ terahedra are inserted between two such layers. The layers are stacked along [001] and linked three-dimensionally by oxygen.     

Über die Reaktion von W3O mit lod. Darstellung,Kristallstruktur und Eigenschaften von WOI3

On the Reaction of W₃O with Iodine: Preparation, Crystal Structure, and Properties of WOI₃ The novel tungsten oxide iodide WOI₃ is obtained from the reaction of the metalrich tungsten oxide W₃O (also known as ‘β-tungsten’) with iodine in a sealed glass tube placed in a temperature gradient (440–400°C). In the low-temperature region WOI₃ is formed as mouse-grey intergrown needle-like crystals. WOI₃ crystallizes in the tetragonal NbOCl₃ structure type, space group P4₂/mnm, with a = 12.346(2), c = 3.765(1) Å (20°C). The crystal structure at – 130°C was determined from single-crystal diffractometer data (R = 0.023). Results of magnetic susceptibility and vibrational spectroscopic measurements are given together with the mass spectrum of WOI₃ obtained on heating.     

Ein,altes‘ Rhodiumsulfid mit überraschender Struktur: Synthese,Kristallstruktur und elektronische Eigenschaften von Rh3S4

An ‘old' Rhodiumsulfide with surprising Structure – Synthesis, Crystal Structure, and Electronic Properties of Rh₃S₄ The reaction of rhodium with rhodium(III)‐chloride and sulfur at 1320 K in a sealed evacuated quartz glass ampoule yields silvery lustrous, air stable crystals of the rhodiumsulfide Rh₃S₄. Although a sulfide of this composition was described in 1935 a closer characterization has not been undertaken. Rh₃S₄ crystallizes in a new structure type in the monoclinic space group C2/m with a = 1029(2) pm, b = 1067(1) pm, c = 621.2(8) pm, β = 107.70(1)°. Besides strands of edge‐sharing RhS₆ octahedra which are connected by S₂ pairs (S–S = 220 pm), the crystal structure of Rh₃S₄ contains Rh₆ cluster rings in chair conformation with Rh–Rh single bond lengths of 270 pm. Both fragments are linked by common sulfur atoms. Extended Hückel calculations indicate bonding overlap for both S–S‐ and Rh–Rh‐interactions. Rh₃S₄ has a composition between the neighboring phases Rh₂S₃ and Rh₁₇S₁₅ and the structure combines typical fragments of both: RhS₆‐octahedra from Rh₂S₃ and domains of metal‐metal bonds as found in Rh₁₇S₁₅. Rh₃S₄ is a metallic conductor, down to 4.5 K the substance shows a weak, temperature independent paramagnetism.     

Ein Polyphosphid mit Rhenium-Clustern: Synthese und Kristallstruktur von Re6P13

A Polyphosphide with Rhenium Clusters: Synthesis and Crystal Structure of Re₆P₁₃ Microcrystalline Re₆P₁₃ was prepared by heating the elemental components in the presence of iodine. Single crystals were obtained by reaction of the components in molten tin. They are rhombohedral, R3 , with the hexagonal cell dimensions: a = 15.665(9), c= 8.320(2) Å, Z = 6. The structure was determined and refined from single-crystal data(R = 0.053). The Re atoms are coordinated by six P atoms in distorted octahedral configuration. Four edge-sharing octahedra are distorted in such a way that Re? Re bonds (2.76 to 2.94 Å) are formed. All P atoms are tetrahedrally coordinated by Re and P atoms. The P atoms form six-membered rings, four membered chains, and pairs. One P atom has only Re neighbors. The crystal structure of Re₆P₁₃ is discussed together with the structures of related compounds.     

Über Tellurhalogenide des Kupfers mit hoher Ionen-Teilleitfähigkeit Die Kristallstruktur von CuTeJ

Telluride Halides of Copper with High Ionic Partial Conductivity. The Crystal Structure of CuTeI Copper telluride iodide, CuTeI, which has a high copper(I) ionic partial conductivity, could be obtained as crystals and the structure determined (359 hkl, R = 0.031). The space group is I4₁/amd with the lattice constants a = 17.170, c = 4.876 Å, and Z = 16. Characteristic for the structure are the helicoidal arrangements of the tellurium atoms, symmetry related by fourfold screwaxes (4₁) and the statistical population of the Cu sites. The latter is a hint for a copper ionic conductivity.     

Reaktion von 3-Dimethylamino-2,2-dimethyl-2H-azirin mit 6-Methyluracil; Kristallstruktur der Reaktionsprodukte

Reaction of 3-Dimethylamino-2,2-dimethyl-2H-azirine with 6-Methyluracil; Crystal Structure of the Products The reaction of 3-dimethylamino-2,2-dimethyl-2H-azirine ( 1 ) with 6-methyl-uracil ( 4 ) in 2-propanol at 80° yields the 4H-imidazoje derivative 5 as the main product. This reaction is similar to the previously reported ones with heterocyclic compounds containing the sequence NH? CO? NH? CO. In the presence of water, 5 is easily hydrolyzed to 6 . The structures of 5 and 6 have been established by X-ray crystallography.