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  • 1H, 31P, 7Li-NMR spectra  (1)
  • Asymmetric [As3]7- anion  (1)
  • Carbosilanes  (1)
  • 1
    ISSN: 0044-2313
    Keywords: Asymmetric [As3]7- anion ; Zintl phase ; defect Ca14AlSb11 structure ; tetraarsaniobate(V) anion ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sr13□NbAs11 und Eu13□NbAs11, Defektvarianten der Ca14AlSb11-Struktur mit asymmetrischen [As3]7--AnionenDie neuen Verbindungen Sr13NbAs11 und Eu13NbAs11 wurden aus den Elementen Sr, Nb und As sowie den binären Komponenten SrAs und Eu5As4 synthetisiert (Niobampullen; 1173 - 1273 K). Die tetragonalen tI 200-Phasen sind Defektvarianten der Ca14AlSb11-Struktur (Raumgruppe I41/acd (Nr. 142); Sr13□NbAs11: a = 1649.8(2) und c = 2214.1(3); Eu13□NbAs11: a = 1632.9(8) und c = 2197.3(8) pm; Z = 8). Die Strukturen sind aufgebaut aus den Kationen Sr2+ und Eu2+, den Anionen [NbAs4]7- und As3- sowie dem linearen Polyanion [As3]7-. Das Polyanion (isoster mit I3-) ist asymmetrisch mit den Bindungslängen d(As—As) = 273.0 und 346.0 pm (Sr) bzw. d(As—As) = 274.7 und 335.6 pm (Eu). Die Bindungslängen in den tetraedrischen Anionen betragen d(Nb—As) = 250.8 bzw. 251.1 pm. Die gesamte strukturelle Anordnung entspricht derjenigen von Cu2O durch die Ausbildung zweier sich durchdringender Netzwerke. Dabei werden die O-Atome durch As4-Tetraeder ersetzt (zentriert durch Nb) und die Cu-Atome durch As6-Oktaeder (zentriert durch Sr bzw. Eu). Die zentralen As-Atome der Polyanionen verbinden die Netze miteinander. Beide As-Netze werden von den restlichen Kationen eingehüllt, welche Würfel, tetragonale Antiprismen und überkappte trigonale Prismen ausbilden.
    Notes: The novel compounds Sr13NbAs11 and Eu13NbAs11 have been synthesized from SrAs, Eu5As4, Sr, Nb and As in niobium ampoules at 1173-1273 K. The tetragonal tI 200 phases are defect variants of the Ca14AlSb11 structure (space group I41/acd (no. 142); Sr13□NbAs11: a = 1649.8(2) and c = 2214.1(3); Eu13□NbAs11: a = 1632.9(8) and c = 2197.3(8) pm; Z = 8). The structures are built from the cations Sr2+, and Eu2+, respectively, and from the anions [NbAs4]7-, As3-, and the linear polyanion [As3]7-. This polyanion (isosteric to I3-) is asymmetric with d(As—As) = 273.0 and 346.0 pm (Sr) and 274.7 and 335.6 pm (Eu), respectively. The bond lengths in the tetrahedral anions are d(Nb—As) = 250.8 and 251.1 pm. The complete structural arrangement is related to that of Cu2O by forming two interpenetrating networks. The oxygen atoms are substituted by niobium centered As4 tetrahedra, and the Cu atoms are substituted by As6 octahedra (centered by Sr, Eu). The central As atoms of the polyanions connect the nets. Both As networks are enveloped by the remaining cations forming cubes, tetragonal antiprisms and capped trigonal prisms.
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  • 2
    ISSN: 0044-2313
    Keywords: Carbosilanes ; Cu-catalyzed reactions of silicon with C-chlorinated 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexanes ; crystal structures of hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane ; decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane and decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation of Organosilicon Compounds 113. Reactions of C-chlorinated 1,1,3,3,5,5-Hexachloro-1,3,5-trisilacyclohexanes with Si(Cu cat.). Structures of Hexadecachloro-1,3,5,7,9,11,13,14-octasiladispiro[5.1.5.1]tetradecane 12, Decachloro-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 13 and Decachloro-2-trichlorosilyl-1,3,5,7,9,11-hexasilatricyclo[6.4.0.02,7]dodecane 14Elemental Si(Cu cat.) was treated with 1,1,2,2,3,3,5,5-octachloro-1,3,5-trisilacyclohexane 3, 1,1,2,2,3,3,4,4,5,5-decachloro-1,3,5-trisilacyclohexane 4 and with (Cl2Si—CCl2)3 5, resp., in a stirred bed reactor at 330°C. The products can be understood as to be formed by silylation, hydrogenation, degradation, rearrangement and condensation reactions all of them starting from the CCl2 groups of the trisilacyclohexanes. Especially remarkable is Si8C6H8Cl16 12 with a C-spiro linked framework formed by a trisilacyclohexane, a disilacyclobutane and another trisilacyclohexane building block. In two further tricyclic carbosilanes Si6C6H10Cl10 13 and Si7C6H9Cl13 14, two trisilacyclohexane rings each share an opposite Si—C bond with a disilacyclobutane. Another group of compounds includes compounds consisting of two 1,3,5-trisilacyclohexane rings linked by either a C=C or a C=C=C unit. Moreover some derivatives of 1,3-disilacyclopentenes are formed obviously by a contraction of the C-chlorinated 1,3,5-trisilacyclohexane rings. Compound 12 crystallizes in the monoclinic space group P21/n (no. 14) with a = 1 307.8, b = 1 184.2, c = 984.4 pm, β = 93.58° and Z = 2 molecules per unit cell. 13 crystallizes in the triclinic space group P1 (no. 2) with a = 885.7, b = 911.6, c = 868.3 pm, α = 113.15°, β = 75.36° γ = 119.22° and Z = 1. 14 crystallizes in the monoclinic space group P21/c (no. 14) with a = 1853.2, b = 912.9, c = 1725.3 pm, β = 112.69° and Z = 4.
    Notes: 1,1,2,2,3,3,5,5,-Octachlor-1,3,5-trisilacyclohexan 3, 1,1,2,2,3,3,4,4,5,5-Decachlor-1,3,5-trisilacyclohexan 4 und (Cl2Si—CCl2)3 5 wurden mit Si(Cu) bzw. Cu im Rührbett bei 330°C umgesetzt. Die Reaktionen gehen von den CCl2-Gruppen der Trisilacyclohexane aus, und die verschiedenen Reaktionsprodukte sind durch Silylierung, Hydrierung, Kondensation und Umlagerung zu erklären. Besonders bemerkenswert ist das Si8C6H8Cl16 12, in dessen Grundgerüst zwei 1,3,5-Trisilacyclohexane über einen Disilacyclobutanring C-spiroverbrückt sind. In zwei tricyclischen Carbosilanen, Si6C6H10Cl10 13 und Si7C6H9Cl13 14, sind zwei Trisilacyclohexane über einen Disilacyclobutanring verbunden, der unter Ausbildung von zwei Si—C-Bindungen zwischen gegenüberliegenden SiCl- und CCl-Gruppen aufgebaut ist. Eine weitere Gruppe enthält Verbindungen, in denen zwei 1,3,5-Trisilacyclohexanringe entweder über eine C=C- oder C=C=C-Gruppe verbunden sind. Es entstehen auch 1,3-Disilacyclopentenderivate, deren Bildung auf eine Ringverengung der C-chlorierten 1,3,5-Trisilacyclohexane zurückgeführt wird. Verbindung 12 kristallisiert monoklin in der Raumgruppe P21/n (Nr. 14) mit a = 1 307,8, b = 1 184,2, c = 984,4 pm, β = 93,58° und Z = 2 Molekülen pro Elementarzelle; 13: triklin in der Raumgruppe P1 (Nr. 2) mit a = 885,7, b = 911,6, c = 868,3 pm, α = 113,15°, β = 75,36°, γ = 119.22° und Z = 1; 14: monoklin in der Raumgruppe P21/c (Nr. 14) mit a = 1 853,2, b = 912,9, c = 1 725,3 pm, β = 112.69° und Z = 4.
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  • 3
    ISSN: 0044-2313
    Keywords: Li(THF)2[η2-(tBu2P)2P] ; Li(TMEDA)[η2-(tBu2P)2P] ; Li(THF)2[η2-(iPr2P)2P] ; Li(THF)2[η2-(Et2N)2P—P—PtBu2] ; Li(THF)2[η2-(tBu2P—P—PiPr2)] ; (tBu2P)2P—SiMe3 ; crystal structures ; 1H, 31P, 7Li-NMR spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation and Structure of Li(THF)2[η2-(tBu2P)2P], Li(TMEDA)[η2-(tBu2P)2P], Li(THF)2[η2-(iPr2P)2P], Li(THF)2[η2-(Et2N)2P—P—PtBu2], Li(THF)2[η2-(tBu2P—P—PiPr2] and (tBu2P)2P—SiMe3The formation and crystal structures of the compounds (tBu2P)2P—SiMe3 1, Li(THF)2[η2-(tBu2P)2P] 2, Li(TMEDA)[η2-(tBu2P)2P] 3, Li(THF)2[η2-(iPr2P)2P] 4, Li(THF)2[η2-(Et2N)2P—P—PtBu2] 5 and Li(THF)2[η2-(tBu2P—P—PiPr2)] 6 are reported. Compounds 3-6 are formed by reacting the corresponding silylated triphosphanes with nBuLi: 2 and 3 result from (tBu2P)2P—SiMe3 1, 4 from (iPrP)2P—SiMe3, 5 from (Et2N)2P—P(SiMe3)—PtBu2 and 6 from tBu2P—P(SiMe3)—PiPr2. 1 crystallizes in the orthorhombic space group P212121 (no. 19) with a = 910.87(7) pm, b = 1132.5(1) pm, c = 2373.5(2) pm (determined at 90 K). The structure determination of 2 was performed at 293 K and 200 K, respectively. 2 crystallizes in the monoclinic space group P21/n (no. 14) with a = 1069.7(3) pm, b = 1802.5(3) pm, c = 1604.0(7) pm, β = 98.11(2)° (200 K); 3 also in P21/n (no. 14) with a = 904.3(2) pm, b = 1936.4(5) pm, c = 1653.2(3) pm, β = 94.52(1)° (200 K). 4 crystallizes monoclinically in C2/c (no. 15) with a = 1650.0(5) pm, b = 945.6(3) pm, c = 1779.8(5) pm, β = 108.81(2)° (200 K); 5 in P21/n (no. 14) with a = 939.4(5) pm, b = 1736.8(6) pm, c = 1943.3(7) pm, β = 98.17(4)° (200 K). All compounds contain Z = 4 molecules in the unit cell.The 1H, 31P and 7Li NMR spectra of 2-6 are discussed.
    Notes: Es wird über die Verbindungen (tBu2P)2P—SiMe3 1, Li(THF)2[η2-(tBu2P)2P] 2, Li(TMEDA) · [η2-(tBu2P)2P] 3, Li(THF)2[η2-(iPr2P)2P] 4, Li(THF)2[η2-(Et2N)2P—P—PtBu2] 5 und Li(THF)2[η2-(tBu2P—P—PiPr2)] 6 berichtet. Letztere bilden sich durch Umsetzung der entsprechenden silylierten Triphosphane mit nBuLi: 2 und 3 aus (tBu2P)2P—SiMe3 1, 4 aus (iPr2P)2P—SiMe3, 5 aus (Et2N)2—P · (SiMe3)—PtBu2, 6 aus tBu2P—P(SiMe3)—PiPr2.1 kristallisiert orthorhombisch in P212121 (Nr. 19) mit a = 910,87(7) pm, b = 1132,5(1) pm, c = 2373,5(2) pm (bei 90 K bestimmt). Die Strukturbestimmung von 2 erfolgte bei 293 K und 200 K. 2 kristallisiert monoklin in P21/n (Nr. 14) mit a = 1069,7(3) pm, b = 1802,5(3) pm, c = 1604,0(7) pm, β = 98,11(2)° (200 K), 3 ebenfalls in P21/n (Nr. 14) mit a = 904,3(2) pm, b = 1936,4(5) pm, c = 1653,2(3) pm, β = 94,52(1)° (200 K). 4 kristallisiert monoklin in C2/c (Nr. 15) mit a = 1650,0(5) pm, b = 945,6(3) pm, c = 1779,8(5) pm, β = 108,81(2)° (200K), 5 in P21/n (Nr. 14) mit a = 939,4(5) pm, b = 1736,8(6) pm, c = 1943,3(7) pm, β = 98,17(4)° (200 K). Alle fünf Verbindungen enthalten jeweils vier Formeleinheiten in der Elementarzelle.Es wird über die Untersuchung der 1H-, 31P- und 7Li-NMR-Spektren der Verbindungen 2-6 berichtet.
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