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  • 11
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 805-810 
    ISSN: 0044-2313
    Keywords: Gadolinium compounds ; preparation ; crystal structures ; DTA-TG analysis ; X-ray powder pattern ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure and Thermal Behaviour of Gadolinium(III)-sulfate-octahydrate Gd2(SO4)3 · 8 H2O.Gd2(SO4)3 · 8 H2O crystallizes monoclinic with space group C2/c and the lattice constants a = 13.531(7), b = 6.739(2), c = 18.294(7) Å, β = 102.20(8)°. In the structure Gd is coordinated by 4 oxygen atoms of crystal water and 4 oxygens of sulfate giving rise to a distorted square antiprism. During DTA-TG-experiments the title compound first loses crystal water in a two-step mechanism in the temperature range 130-306°C. The resulting Gd2(SO4)3 is amorphous and recrystallization occurs in the range 380-411°C. The so-obtained low-temperature modification β-Gd2(SO4)3, undergoes a monotropic phase transition at about 750°C to the high-temperature form α-Gd2(SO4)3. The powder pattern of this modification was indexed based on monoclinic symmetry with space group C2/c and lattice constants a = 9.097(3), b = 14.345(5), c = 6.234(2) Å, β = 97.75(8)°. The hightemperature modification of gadolinium-sulfate shows decomposition to Gd2O2SO4 at 900°C and, subsequently, decomposition at 1 200°C yields the formation of C-Gd2O3.
    Notes: Gd2(SO4)3 · 8 H2O kristallisiert monoklin in der Raumgruppe C2/c mit den Gitterkonstanten a = 13,531(7), b = 6,739(2), c = 18,294(7) Å und β = 102,20(8)°. In der Struktur ist Gd von je 4 Sauerstoffatomen des Hydratwassers und der Sulfationen in Form eines stark verzerrten quadratischen Antiprismas umgeben. Im DTA-TG-Experiment verliert Gd2(SO4)3 · 8 H2O in einem zweistufigen Prozeß im Temperaturbereich 130-306°C zunächst Kristallwasser; anschließend tritt zwischen 380 und 411°C Rekristallisation des amorphen Gd2(SO4)3 unter Bildung der Tieftemperaturmodifikation β-Gd2(SO4)3 auf. Bei ca. 750°C wird monotrop die Hochtemperaturmodifikation α-Gd2(SO4)3 gebildet. Aus der Analyse der Pulverdaten folgt monokline Symmetrie mit der Raumgruppe C2/c und den Gitterkonstanten a = 9,097(3), b = 14,345(5), c = 6,234(2) Å und β = 97,75(8)°. Ab ca. 900°C beginnt die Zersetzung von α-Gd2(SO4)3 zu Gd2O2SO4 und ab 1 200°C liegt C-Gd2O3 vor.
    Additional Material: 2 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 491 (1982), S. 34-38 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure of MgHg(SCN)4 · 2 H2OThe crystal structure of the monoclinic MgHg(SCN)4 · 2 H2O (a = 1 335.1(6) pm, b = 531.6(5) pm, c = 1 867.0(14) pm, β = 92.3(1)°, Z = 4, space group C2/c) contains nearly tetrahedral Hg(SCN)4 and octahedral Mg(OH2)2(NCS)4 groups. These groups are joined together with Hg—SCN—Mg bridges and are forming a network of layers.
    Notes: In der Kristallstruktur des monoklinen MgHg(SCN)4 · 2 H2O (a = 1 335,1(6) pm, b = 531,6(5) pm, c = 1 867,0(14) pm, β = 92,3(1)°, Z = 4, Raumgruppe C2/c) sind annähernd tetraedrische Hg(SCN)4- und oktaedrische Mg(OH2)2(NCS)4-Baugruppen über Hg—SCN—Mg-Brücken zu Schichten verbunden.
    Additional Material: 1 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 516 (1984), S. 30-34 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure of BaHg(CN)4 · 4 PyridineThe structure of the tetragonal BaHg(CN)4 · 4 Pyridine (space group I4, a = 1119.4(7), c = 1 057.9(7) pm, Z = 2, dc = 1.87 g · cm-3) contains tetrahedral Hg(CN)4 and bisdisphenoide Ba(NC)4(py)4 groups, which are linked together by Hg—CN—Ba bridges. The BaHg(CN)4 framework consists of a 3-dimensional network of all round edge-sharing tetrahedrons. The analogous strontium compound is isotype with a = 1 108.2(9) and c = 1 035.3(14) pm.
    Notes: In der Struktur des tetragonalen BaHg(CN)4 · 4 Pyridin (Raumgruppe I4, a = 1119,4(7), c = 1 057,9(9) pm, Z = 2, dc = 1,87 g · cm-3) sind tetraedrische Hg(CN)4- und bisdisphenoide Ba(NC)4(py)4-Gruppen über Hg—CN—Ba-Brücken zu einem Raumnetz verknüpft. Dem BaHg(CN)4-Gerüst liegt ein Aufbau aus allseitig eckenverknüpften Tetraedern zugrunde. Die analoge Strontium-Verbindung ist isotyp mit a = 1 108,2(9) und c = 1 035,3(14) pm.
    Additional Material: 2 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 499 (1983), S. 15-19 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure of SrHg(SCN)4 · 3 H2OSrHg(SCN)4 · 3 H2O is orthorhombic, space group Pcca, with a = 19.476(7), b = 8.150(1), c = 8.991(3) Å, V = 1427.1 Å3, Z = 4, dc = 2.67 g · cm-3, μ(AgKα) = 77.95 cm-1.The salt consists of nearly tetrahedral Hg(SCN)4 groups, Sr has a tricapped trigonal prismatic coordination: four N and five O atoms. The thiocyanate groups form end-to-end bridges and connect the Hg and Sr coordination polyhedra.
    Notes: SrHg(SCN)4 · 3H2O ist orthorhombisch, Raumgruppe Pcca, mit a = 19,476(7), b = 8,150(1), c = 8,991(3) Å, V = 1427,1 Å3, Z = 4, dc = 2,67 g · cm-3, μ(AgKα) = 77,95 cm-1.In der Verbindung sind annähernd tetraedrische Hg(SCN)4-Einheiten enthalten. Sr besitzt eine tricapped trigonal prismatische Koordination (4 N- und 5 O-Atome). Die Thiocyanatogruppen liegen als end-to-end-Brücken vor und verbinden die beiden Koordinationspolyeder.
    Additional Material: 1 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 500 (1983), S. 171-180 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Dicyanothiocyanatomercurates(II) of the Alkaline-earth MetalsThe reactions between Hg(CN)2 and M(NCS)2 · nH2O (M = Mg, Ca, Sr, Ba; n = 3, 4) in aqueous solutions lead to the compounds M[Hg(CN)2SCN]2 · 4 H2O. The compounds yielded by crystallization are characterized with x-ray, spectroscopic, and thermal methods. The crystal structures of Mg[Hg(CN)2SCN]2 · 4 H2O and Sr[Hg(CN)2SCN]2 · 4 H2O have been determined by x-ray structure analysis. These structures can be compared with the compounds M′Hg(CN)2SCN (M′ = K, Rb, Cs).
    Notes: Durch Reaktion zwischen Hg(CN)2 und den Erdalkalithiocyanaten M(NCS)2 · nH2O (M = Mg, Ca, Sr, Ba; n = 3, 4) in H2O wurden die Verbindungen M[Hg(CN)2SCN]2 · 4H2O dargestellt. Die kristallinen Spezies wurden durch röntgenographische, spektrometrische und thermische Methoden charakterisiert. Die Strukturen der Verbindungen mit M = Mg und Sr konnten bestimmt werden. Der strukturelle Aufbau läßt Vergleiche mit den entsprechenden Verbindungen der Alkaliionen M′Hg(CN)2SCN (M′ = K, Rb, Cs) zu.
    Additional Material: 4 Ill.
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  • 16
    ISSN: 0044-2313
    Keywords: Gold complexes ; preparation ; crystal structures ; ab initio Hartree-Fock calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Dimeric Gold Selenolates: Preparation and Characterization of [(n-C4H9)4N]2[AuSSeC = C(CN)2]2 and [(n-C4H9)4N]2[AuSe2C = C(CN)2]2The preparation and structural characterization of the dimeric AuI complexes of 1,1-dicyanoethene-2,2-thioseleonlate (i-mnts) and 1,1-dicyanoethene-2,2-diselenolate (i-mns), isolated as Bu4N salts, are described. They are isotype (monoclinic, space group P21/c, Z = 2) with lattice parameters: (Bu4N)2[Au(i-mnts)]2; a = 14.078(3) Å, b = 8.912(3) Å, c = 20.142(4) Å, β = 106.32(5)°; (Bu4N)2[Au(i-mns)]2; a = 13.998(3) Å, b = 9.125(3) Å, c = 20.039(2) Å, β = 105.12(5)°. Ab initio Hartree-Fock calculations based on the experimentally determined structure yield a positive value of the Au—Au bonding order suggesting weak bonding interactions between the d10 metal centres.
    Notes: Die Darstellung und Strukturaufklärung der als Bu4N-Salze (Bu = n-C4H9) isolierten dimeren AuI-Komplexe des 1,1-Dicyanoethen-2,2-thioselenolats (i-mnts) und des 1,1-Dicyanoethen-2,2-diselenolats (i-mns) werden beschrieben. Sie kristallisieren zueinander isotyp (monoklin, Raumgruppe P21/c, Z = 2) mit folgenden Gitterkonstanten: (Bu4N)2[Au(i-mnts)]2; a = 14,078(3) Å, b = 8,912(3) Å, c = 20,142(4) Å β = 106,32(5)°; (Bu4N)2[Au(i-mns)]2; a = 13,998(3) Å, b = 9,125(3) Å, c = 20,039(2) Å, β = 105,12(5)°. Ab-initio-Hartree-Fock-Rechnungen unter Zugrundelegung der experimentell bestimmten Geometrie mit Kristallfeldsimulation liefern einen positiven Wert der Au—Au-Bindungsordnung, der darauf hindeutet, daß der kurze Au—Au-Abstand (2,810(1) äR) auf schwache bindende Wechselwirkungen zwischen den d10-Metallzentren zurückgeführt werden kann.
    Additional Material: 1 Ill.
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  • 17
    ISSN: 0044-2313
    Keywords: Tantalum disulfide ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Tribochemical Hydrolysis of 2H—TaS2 and on the Thermal Decomposition of Partially Hydrolysed 2H—TaS2On intense grinding of 2 H-TaS2 in automatic mortars a partial hydrolysis occurs, accompanied by evaluation of H2S. Also traces of atmospheric water are intercalated. It is shown that texture-effects in powder diagrams are reduced significantly by grinding. The critical temperature indicating superconductivity is raised from 0.7 K to 1.8 K by the grinding procedure.The thermal decomposition of ground TaS2 starts at 185° C and a maximum is reached at 233° C. The gaseous decomposition products are monitored by DTA-TG-QMS technique and consist of H2O, H2S, SO2 and simple sulfur fragments S, S2, and S3. Up to 1000° C a total mass-loss of 18.5% is monitored and solid decomposition products are TaS2-x and Ta2S.
    Notes: 2H—TaS2 unterliegt beim Kugelmahlprozeß in der Schwingmühle einer partiellen Hydrolyse unter H2S-Freisetzung; außerdem werden Spuren von Wasser aus der Atmosphäre eingelagert. Das gemahlene TaS2 zeigt im Pulverdiffraktogramm nur geringe Textureffekte, die Sprungtemperatur, die den Übergang in den supraleitenden Zustand markiert, steigt von 0,7 K für nicht vorbehandeltes Disulfid auf 1,8 K an.Das gemahlene TaS2 ist thermolabil-der thermische Abbau wurde mit DTA—TG—QMS Technik untersucht. Die Zersetzung beginnt bei 185°C und erreicht ein Maximum bei 233°C durch Abspaltung von H2O, H2S, SO2 und den Schwefelfragmenten S, S2, und S3. Im Temperaturbereich von RT bis 1000°C wird ein maximaler Massenverlust von 18,5 Gew.% registriert, als Abbauprodukte können TaS2-x und das Subsulfid Ta2S nachgewiesen werden.
    Additional Material: 6 Ill.
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