Eine Verbindung, die mit Schwermetallsalzen innere Komplexe

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Pentacalciumhexaphosphahypodiphosphat,Ca5P8: Eine Verbindung mit isolierten Anionen P810− mit der gestaffelten Konformation von Ethan

Pentacalcium Hexaphosphahypodiphosphate, Ca₅P₈, a Compound with Isolated Anions P₈^10? in the Staggered Ethane Conformation Ca₅P₈ is prepared from calcium and red phosphorus in a molar ratio 5:8 in argon atmosphere in corundum crucibles inserted in quartz ampullae (3.5 d 1 000°C). It is a red-brown powder which is hydrolyzed by moisture. Single crystals are formed from powder at 1 100°C within 60 d. Ca₅P₈ crystallizes in a new structure type (mC26) with isolated anions P₈^10? in staggered conformation: C2/m (no. 12); a = 689.9(4) pm, b = 1 188,3(4) pm, c = 748.4(3) pm, β = 108.25(2)°, Z = 2; d = 2.56(1). Ca₅P₈ is the first compound containing polyphosphide anions with fourfold and single bonded phosphorus atoms (formally P⁺ and P^2?, resp.). The cations Ca²⁺ are arranged in a distorted cubic close-packing. The centers of the polyphosphide anions replace in an ordered way one third of Ca²⁺ in every second layer. The terminal P atoms occupy all octahedral interstices, so that P₈^10? is coordinated by 18 Ca²⁺ in form of a cuboctahedron with capped squaric faces.     

Eine neue metastabile Verbindung mit eigenem Strukturtyp: BaNi2In8O15

A New Metastable Compound with a Hitherto Unknown Structure Type: BaNi₂In₈ O₁₅ A new metastable compound: BaNi₂In₈O₁₅ was prepared by high temperature technique and investigated by X-ray single crystal studies. It crystallizes with orthorhombic symmetry, space group D_2h¹⁸–Cmca (a = 12.2811, b = 11.0214, c = 9.9103 Å; Z = 4). A typical feature of the metastable property of BaNi₂In₈O₁₅ is the statistical occupation of one of the point positions with In³⁺ and Ni^2? ions. The structure, especially the InO₆/NiO₆-octahedral network are shown and discussed in respect to the metastable behavior of BaNi₂In₈O₁₅.     

Eine mit Tetraederketten aufgefüllte Rutilstruktur: Die Verbindung CaCu4P2≙CaP2(Cu4)

Rutile-Type Structure with Chains of Tetrahedra: The Compound CaCu₄P₂ CaCu₄P₂ was prepared by heating the elements (slight excess of Cu, 850–950°C) and investigated by single crystal X-ray methods. The compound crystallizes tetragonally in a rutile-type structure (P4₂/mnm, a = 729.0(2) pm, c = 383.1(1) pm) built up by Ca and P atoms in which Cu atoms occupy the vacancies in form of chains of edge-shared tetrahedra.     

Ti9Se2 – Eine Verbindung mit kolumnaren [Ti9]-Baueinheiten

The Metal-Rich Titanium Selenide Ti₉Se₂ The new compound Ti₉Se₂ has been prepared as hitherto most metal-rich phase in the system titanium-selenium. It crystallizes in the orthorhombic space group Pbam (No. 55) with a = 691.7(2), b = 1 550.5(9), c = 345.4(2) pm. The structure consists of [Ti₉]-strings which are described within the concept of condensed clusters. The Se atoms are coordinated by tricapped trigonal prisms of Ti atoms.     

Eine Spektralphotometrische Calciumbestimmung mit 8-Hydroxychinolin

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Eine Kristalline Kieselsäure mit hoher Einlagerungsfähigkeit

Crystalline Silicic Acid with Distinct Intracrystalline Reactivity The crystalline silicic acid H₂Si₂₀O₄₁ · xH₂O is obtained from its alkali and alkaline-earth salts by cation exchange. The crystalline silicic acid and its salts form layered host lattiees which interealate many organic compounds. The increased intracrystalline reactivity and the reversible swelling in water distinguish H₂Si₂₀O₄₁ · xH₂O from the other silicic acids. Differences between samples of H₂Si₂₀O₄₁ · xH₂O are detected by intracrystalline reactions more clearly than by X-ray diffraction studies. Thermal dehydration at about 150°C gives Siliea-X, a partially dehydrated form (about SiO₂ · 0,09 H₂O). The aggregation of the plate-like crystals to spherical aggregates provides an interesting material for interface reactions.