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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 823-828 
    ISSN: 0044-2313
    Keywords: Tellurium ; niobium oxytrihalides ; hexatellurium(2+) ; tetrachlorooxoniobate (1-) ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Prismatic Te62+ Ion in the Structure of Te6(NbOCl4)2Te6(NbOCl4)2 is obtained from Te, TeCl4 and NbOCl3 at 200°C. It crystallizes triclinic, space group P1 (a = 915,5(4) pm, b = 1655,3(6) pm, c = 3134,4(9) pm, α = 42,62(2)°, β = 117,12(6)°, γ = 138,24(8)°). The crystal structure analysis shows, that the structure is built of one-dimensional polymeric ∞1[NbOCl4-] chains in which the monomers are linked via linear O—Nb—O-bridges and from discrete Te62+ polycations that are also arranged in strands, but without significant interactions. The structure is closley related but not isotypic to the previously reported tungsten containing analogue Te6(WOCl4)2 (monoclinic, P21/c). A comparison of the two structures shows that rotations of the cationic strands relative to the anionic strands lead to different cation-anion interactions.
    Notes: Te6(NbOCl4)2 wird aus Te, TeCl4 und NbOCl3 bei 200°C erhalten. Es kristallisiert triklin, P1, a = 915,5(4) pm, b = 1655,3(6) pm, c = 3134,4(9) pm, α = 42,62(2)°, β = 117,12(6)°, γ = 138,24(8)°. Die Kristallstrukturanalyse zeigt, daß die Struktur aus eindimensional-polymeren, über O-Atome verknüpften ∞1[NbOCl4-]-Strängen und aus diskreten, strangartig angeordneten Te62+-Polykationen aufgebaut ist. Die Struktur ist eng verwandt, aber nicht isotyp mit derjenigen der analogen wolframhaltigen Verbindung Te6(WOCl4)2 (monoklin, P21/c). Ein Strukturvergleich zeigt, daß Verdrehungen der Kationenstränge relativ zu den Anionensträngen zu unterschiedlichen Kation-Anionwechselwirkungen führen.
    Additional Material: 5 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 1971-1975 
    ISSN: 0044-2313
    Keywords: Tellurium ; niobium oxytrihalides ; poly(heptatellurium(2+)) ; tetrachlorooxoniobate (1-) ; tetrabromooxoniobate (1-) ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tellurium Cations stabilized by Niobium Oxytrihalides: Synthesis and Crystal Structure of Te7NbOBr5 and Te7NbOCl5The reaction of Te2Br with NbOBr3 in a sealed evacuated glass ampoule at 225°C yields Te7NbOBr5 in form of bright black needles. Te7NbOCl5 is obtained from tellurium, TeCl4 and NbOCl3 at 220°C. Both compounds crystallize orthorhombic in the space group Pcca (Te7NbOBr5: a = 2 651,9(4) pm, b = 836.6(1) pm, c = 794.6(1) pm; Te7NbOCl5: a = 2 597.7(5) pm, b = 805.1(1) pm, c = 791.2(1) pm). The crystal structure determinations show that Te7NbOBr5 and Te7NbOCl5 are built of one-dimensional polymeric tellurium cations, one-dimensional associated pyramidal NbOX4 groups (X = Cl, Br) and isolated halide anions. Magnetic properties of Te7NbOX5 were determined and confirm the expected diamagnetism. Te7NbOX5 can thus be formulated as ∞1[Te72+] ∞1[NbOX4-] (X-). The charge distribution in the structure type Te7MOX5 (M = W, Nb; X = Cl, Br) became clear by synthesis and characterisation of the two niobium containing compounds.
    Notes: Durch Reaktion von Te2Br mit NbOBr3 in einer evakuierten Glasampulle bei 225°C entsteht Te7NbOBr5 in Form von schwarzglänzenden, stäbchenförmigen Kristallen. Te7NbOCl5 wird aus Te, TeCl4 und NbOCl3 bei 220°C erhalten. Beide Verbindungen kristallisieren im orthorhombischen Kristallsystem in der Raumgruppe Pcca (Te7NbOBr5: a = 2 651,9(4) pm, b = 836,6(1) pm, c = 794,6(1) pm; Te7NbOCl5: a = 2 597,7(5) pm, b = 805,1(1) pm, c = 791,2(1) pm). Die Kristallstrukturanalysen zeigen, daß Te7NbOBr5 und Te7NbOCl5 aus eindimensionalen polymeren Tellur-Kationen, eindimensionalen Strängen von pyramidalen, über O-Atome assoziierten NbOX4-Einheiten und aus isolierten Halogenidionen aufgebaut sind. Magnetische Messungen bestätigen den erwarteten Diamagnetismus und zeigen, daß Nb in der formalen Oxidationsstufe + V vorliegt. Die ionische Schreibweise lautet daher ∞1[Te72+] ∞1[NbOX4-] (X-). Die Synthese und Charakterisierung der beiden niobhaltigen Vertreter klärt die Ladungsverteilung im Strukturtyp Te7MOX5 (M = W, Nb; X = Cl, Br).
    Additional Material: 4 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 70 (1958), S. 595-595 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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