Präparation und röntgenographische Untersuchung eines neuen Kupfer-Oxoaluminats: Cu2Al4O7

Solid state reaction of CuO and Al₂O₃ with a flux of PbO about 930°C and reaction time of 8d gives the new compound Cu₂Al₄O₇. The red single crystals were examined by energydispersive microanalysis and X-ray diffraction methods. Cu₂Al₄O₇ has cubic symmetry, space group ,a=908.0 pm. The typical coordination of Cu⁺ (CN=6 and CN=12) and the interstitial arrangement of the AlO₄-tetrahedra are discussed with respect to related compounds.

     

Ba6CoNb9O30: Ein neuer Vertreter der tetragonalen Wolframbronzen

Ba₆CoNb₉O₃₀: A New Compound of the Tetragonal Bronze Structure The hitherto unknown compound Ba₆CoNb₉O₃₀ was examined by X-ray single crystal work. (Space group C-P4bm; a = 1258.9; c = 400.9 pm) Co³⁺ and Nb⁵⁺ occupy a special position in an octahedral framework. The coordination of Ba²⁺ is discussed.     

Über Erdalkalimetalloxogallate. VIII Synthese und Aufbau eines neuen Calciumoxogallats: Ca3Ga4O9

The hitherto unknown compound Ca₃Ga₄O₉ was prepared and investigated by X-ray single crystal methods. Ca₃Ga₄O₉ has orthorhombic symmetry:a=1435.8;b=1682.5;c=532.1 pm; space group C _2v ¹¹ –Cmm2,Z=6. The tetrahedra network (circles of 4 and 5 GaO₄-tetrahedra) and the surrounding of Ca²⁺ are described and discussed with respect to other oxogallates.

     

Beiträge zur Chemie der Pyrrolpigmente, 39. Mitt.: Ein Kraftfeldmodell zur konformationsanalytischen Untersuchung von Gallenfarbstoffen

A force field model was designed with respect to the special needs of bile pigments. It is parametrized and tested using partial structures of bile pigments as well as an integral pigment; the solution structures of the molecules were previously deduced using independent experimental methods.

38. Mitt::Falk, H., Schlederer, T., Wolshann, P., Mh. Chem.112, 199 (1981).     

Ein Beitrag zur Stereochemie des Arsens in As(III)—Sauerstoffverbindungen

The oxygen coordination sphere around As(III) consists of the three primary oxygen atoms (average As–O distance 1.78₅ Å) and secondary oxygen atoms between 2.70 and 3.37 Å (3.37 Å is the assumed sum of theVan der Waals radii). Reasons are discussed why neither the number (0–3) nor the length of the secondary As–O distances exert an influence on the geometry of the [AsO₃]-group and its As–O distances.

     

Ein Beitrag zur Pyrochlorstruktur an La2Zr2O7

Single crystals of the compound La₂Zr₂O₇ were prepared for the first time and examined by x-ray investigations. La₂Zr₂O₇ crystallizes in the space group O? Fd3m, a = 10.786 Å. The free oxygen parameter, which is characteristic for the pyrochlore structure, was found to be x = 0.295.     

Synthese und Untersuchung von NiNb2O6-Einkristallen mit Columbit- und Rutilstruktur

Synthesis and Investigation of NiNb₂O₆ Single Crystals of Columbite and Rutil Type C-NiNb₂O₆ (columbite type) and R-NiNb₂O₆ (rutil type) single crystals were prepared by solid state reactions. C-NiNb₂O₆ a = 14.032; b = 5.687; c = 5.033 Å, space group D—Pbcn. R-NiNb₂O₆ a = 4.710; c = 3.038 Å, space group D—P4₂/mnm. The metal positions of the rutil structure are statisticaly occupied by Ni²⁺ and Nb⁵⁺ ions. R-NiNb₂O₆ is in respect to lower temperatures a metastable compound.     

Ein Beitrag zur Kristallstruktur von CuSmMo2O8 und CuGdMo2O8

A Contribution on the Crystal Structure of CuSmMo₂O₈ and CuGdMo₂O₈ Single crystals of (I) CuSmMo₂O₈ and (II) CuGdMo₂O₈ were prepared and investigated using an X-ray technique. Both compounds crystallize with orthorhombic symmetry, space group D-Pbca with Z = 8. ((I): a = 10.302, b = 9.796, c = 14.697 Å; (II): a = 10.200, b = 9.779, c = 14.646 Å). The crystal structure and the classification into the already known Copper(I) Lanthanoidemolybdates are discussed.     

Die Kristallstruktur des Komplexnitrides NbMoN1−x (x≤0,1)

The crystal structure of NbMoN_1–x has been determined from X-ray powder patterns. It is isotypic with the formerly described^1,2 complex nitrides NbCrN and Ta_1–x Cr_1+x N. The tetragonal unit cell contains 6 atoms and belongs to the space groupP4/nmm-D _4h ⁷. The lattice parameters are:a=3,095 Å,c=7,799 Å. The structure is characterized by relatively close packed double layers of Nb-atoms and Mo-atoms parallel to the base plane. The nitrogen atoms are within the octahedral interstitial sites.

     

Zur Struktur der Produkte der Reaktion vonE/Z-1-Benzolsulfonyl-3-(1-pentenyl)-indol mit N-Phenylmaleinimid: Ein erster Beitrag zur Konfigurations- und Konformationsanalyse in der Vinylindol-Cycloadditionsreihe

The products2,3 of the reaction ofE/Z-1-benzenesulfonyl-3-(1-pentenyl)-indole (1) and N-phenylmaleimide were analysed by¹H-NMR spectroscopy. Exemplarily, the structure elucidation of theendo-cyclo-adduct2 b was achieved by using several NMR techniques (diff. NOE-, INDOR-measurements, decoupling experiments, spectra simulation). The¹H-NMR-spectroscopically gained prediction of relative configuration and conformation of2 b was supported on X-ray analysis. The cyclohexene ring of the new cycloadducts adopts in the liquid phase and in the crystal a slightly twisted boat conformation.

     

Kristallstrukturuntersuchung an NiTa2O6-Einkristallen Ein Beitrag zur Systematik geordneter und ungeordneter Oxometallate: AB2O6 und ABO4

Crystal Structure Investigation of NiTa₂O₆-Single Crystals. A Contribution about Ordered and Disordered Oxocompounds: AB₂O₆ and ABO₄ Single crystals of NiTa₂O₆ were prepared and the well known tri-Rutil type refined by X-ray methods. Additionally the compounds of Columbit-composition AB₂O₆ with partly ordered tri-α-PbO₂ structure and statistically metal distribution in the Rutil type are discussed. There are crystal chemical relationships to ABO₄ compounds of the α-PbO₂, Wolframite, and Zn₃Nb₂O₈-type.     

Ein neuer Strukturtyp mit flächenverknüpften BaO6-Oktaedern: Ba6Nd2Al4O15

Summary A compound Ba₆Nd₂Al₄O₁₅ with a new structure-type was prepared by solid state reaction. It crystallizes with hexagonal symmetry, space group C _6v ⁴ – P 6₃mc;a=11.5696;c=6.9662 Å;z=2. Ba₆Nd₂Al₄O₁₅ has a dominating Ba/O-framework with incorporated AlO₆-octahedra and AlO₄-tetrahedra. A main feature of the structure are face connected BaO₆-octahedra. One of the point positions of the heavy atoms is occupied statistically by Ba²⁺ and Nd³⁺.

     

Na2BaCuV2O8: Ein neuer Strukturtyp der Alkali-Erdalkalimetall Kupfer-Oxovanadate

Na₂BaCuV₂O₈: A New Structure Type of the Alkaline-Alkaline Earth Copper Oxovanadates Single crystals of Na₂BaCuV₂O₈ were prepared by a high temperature flux. It crystallizes with monoclinic symmetry space group C–C2/c, a = 9.4329 Å, b = 5.6858 Å, c = 14.0488 Å, β = 92.344° Z = 4 and represents a new structure type. The crystal structure show VO₄ tetrahedra, stretched CuO₆ octahedra, trigonal bipyramids around Na⁺ and a BaO₁₀₊₂ polyedron.     

Beitrag zur Synthese des Hydroxylammoniumfluorids

Summary Hydroxylammonium fluoride was prepared in aqueous solution by the reaction of hydroxylamine with aqueous hydrogen fluoride. The solubility in water (148.7 g/100 g) and ethanol (0.146 g/100 g), the density (1.621±0.005 g/cm³) and the metling point (97.8±2 °C) of the compound have been determined. [NH₃OH]F crystallizes orthorombic, P_abc,a=6.490(1) Å,b=9.799(1) Å,c=13.519(2) Å.

     

Ein Beitrag zur Kristallstruktur von CuYW2O8, CuHoW2O8 und CuYbW2O8

A Contribution on the Crystal Structure of CuYW₂O₈, CuHoW₂O₈, and CuYW₂O₈ Single crystals of (I) CuY₂O₈, (II), CuHoW₂O₈, and (III) CuYbW₂O₈ were prepared and investigated by X-ray technique. (I) crystallizes with triclinic symmetry, space group C? P1 (a = 5.939 Å, b = 6.042 Å, c = 5.025 Å; α = 112.30°, β = 111.77°; Z = 1). (II) and (III) belong to monoclinic symmetry, space group C? P2/n (II) (a = 10.045 Å, b = 5.808 Å, c = 5.021 Å; β = 94.38°; z = 2 (III) a = 9.948 Å, b = 5.824 Å, c = 5.008 Å; β = 93.36°; Z = 2). The crystal structures will be discussed with respect to other to copper rare earth tungstates.     

Physikalisch-chemische Eigenschaften der Halbleiter im System GeS x Se1−x

Specimens of the system GeS _x Se_1–x were examined by means of X-ray and differential thermal analysis for 0x1. The activation energy of the specimens was calculated according to a semi-empirical method on the basis of the known thermodynamic parameters of the components.

     

Zur Kristallchemie der tetragonalen Wolframbronze: Ba6FeNb9O30

Solid state reaction of BaCO₃, FeC₂O₄·2H₂O and Nb₂O₅ gave single crystals of Ba₆FeNb₉O₃₀. The crystal structure was solved by X-ray investigations (a=12.597,c=3.990Å, space group P 4 bm-C _4v ² ,Z=1). Ba₆FeNb₉O₃₀ crystallyzes in the tetragonal bronze type with a statistical distribution of Fe³⁺ and Nb⁵⁺ in the octahedral framework. The anisotropic temperature factors of barium are discussed with respect to the oxygen coordination.

     

Er3O2F5: Ein Erbiumoxidfluorid mit Vernier‐Struktur

Er₃O₂F₅: An Erbium Oxide Fluoride with Vernier‐Type Structure Attempts to synthesize multinary erbium‐trifluoride derivatives (e. g. Er₃F[Si₃O₁₀], Er₄F₂[Si₂O₇][SiO₄], CsEr₂F₇, and RbEr₃F₁₀) from mixtures of ErOF‐contaminated erbium trifluoride (ErF₃) itself and appropriate other components (such as Er₂O₃ and SiO₂ or CsF and RbF, respectively) frequently resulted in the formation of pale pink, transparent, lath‐shaped single crystals of Er₃O₂F₅ (orthorhombic, Pnma; a = 562.48(5), b = 1710.16(14), c = 537.43(4) pm; Z = 4) as by‐product, typically after seven days at 800 °C and regardless of the applied reaction‐container material (evacuated torch‐sealed silica or silica‐jacketed arc‐welded tantalum capsules). Its crystal structure, often described as a vernier‐type arrangement consisting of two interpenetrating and almost misfitting lattices (ErOF and ErF₃), contains two crystallographically different Er³⁺ cations in the eight‐ and seven‐plus‐one‐fold anionic coordination of bicapped trigonal prisms. Whereas (Er1)³⁺ carries four O^2? and F^? anions each, (Er2)³⁺ resides in the neighbourhood of only two O^2?, but five plus one F^? anions. As the main structural feature, however, one can consider O^2?‐centred (Er³⁺)₄ tetrahedra which share common edges to form linear double strands of the composition . Running parallel to the [100] direction and assembling like a hexagonal closest rod‐packing, their electroneutralization and three‐dimensional interconnection is achieved by three crystallographically independent F^? anions (d(F^??Er³⁺) = 221 ? 251 plus 281 pm) in three‐ and two‐plus‐two‐fold coordination of the Er³⁺ cations, respectively.     

Die erste Verbindung mit Mn2+ der Stoffklasse BaMLn2O5: BaMnDy2O5

The First Compound of BaMLn₂O₅-Type Containing Mn²⁺: BaMnDy₂O₅ Single crystals of the hitherto unknown compound BaMnDy₂O₅ were prepared by CO₂-Laser technique and H₂ atmosphere. Four circle diffractometer measurements led to space group D¹⁶_2h-Pnma, a = 12.428; b = 5.766; c = 7.143 Å; Z = 4. It is isotypic to BaCuSm₂O₅ and shows Mn²⁺ in square pyramids of oxygen.