ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0044-2313
    Keywords: Zintl phases with anionic Rb, Na, Au and I ; (ARb6)5+ octahedra ; Sr11Ir4 type ; Li3Bi defect variants ; electrostatic potentials ; volume increments ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Cubic Phases Na16(ARb6)Sb7, Compounds with the Anions A = Rb-, Na-, Au-, I-The novel compounds Na16(ARb6)Sb7 have been synthesized from the elements in sealed Nb ampoules at 873 K (A = Rb) and 823 K (A = I, Na, Au). They form brittle cuboctahedra (silver metallic; A = Rb) and irregular polyhedra (silver metallic lustre; A = Na, I; golden metallic lustre; A = Au). They rapidly decompose in moist air to gray products. Their crystal structures have been determined by single crystal X-ray crystallography (A = Rb: a = 1565.8(2) pm; A = I: a = 1563.3(2) pm; A = Na: a = 1562.6(2) pm; A = Au: a = 1560.7(2) pm). They crystallize cubically in the space group Fm3m (no. 225) with Z = 4 formula units and are isotypic with Sc11Ir4. The compounds are ZINTL phases and their structures can be described as an eightfold defect variant of the Li3Bi type of structure (cF128-8; a = 2a′(Li3Bi)). The Sb atoms form a network of cuboctahedra, centered alternatingly by a SbNa8 cube or a ARb6 octahedron. Main structural features are the anions A- within the Rb6 octahedron. Supporting the existence of A- are the isotypical compounds with the more common anion forming elements (A = Au, I), as well as electrostatic potential considerations together with calculations of the volume increments. The semiconducting properties (Eg = 0.33 eV) of Na16(RbRb6)Sb7, as well as the diamagnetism χmol = -508 × 10-6 cm3 mol-1, are in accordance with those to be expected from the Zintl concept.
    Notes: Die neuartigen Verbindungen Na16(ARb6)Sb7 wurden aus den entsprechenden Elementen in verschweißten Nb-Ampullen bei 873 K (A = Rb) bzw. 823 K (A = I, Na, Au) dargestellt. Sie bilden spröde silberfarbene Kuboktaeder (A = Rb) bzw. unregelmäßige Polyeder (silberglänzend: A = Na, I; metallisch golden glänzend: A = Au). Die Verbindungen zersetzen sich schnell an feuchter Luft zu grauen Produkten. Die Kristallstrukturen wurden an Einkristallen bestimmt (A = Rb: a = 1565,8(2) pm; A = I: a = 1563,3(2) pm; A = Na: a = 1562,6(2) pm; A = Au: a = 1560,7(2) pm). Sie kristallisieren in der Raumgruppe Fm3m (Nr. 225) mit Z = 4 Formeleinheiten und sind isotyp zu Sc11Ir4. Die Verbindungen sind Zintl-Phasen, deren Strukturen als achtfache Defektvariante der Li3Bi-Struktur (cF128-8; a = 2a′ (Li3Bi)) beschrieben werden können. Die Sb-Atome bilden ein Netz von Kuboktaedern, die abwechselnd durch SbNa8-Würfel bzw. durch ARb6-Oktaeder zentriert werden. Wesentliches Strukturmerkmal sind die A--Anionen im Rb6-Oktaeder, deren Existenz durch die Darstellung der isotypen Verbindungen mit typischen Anionenbildnern (A = Au, I), durch elektrostatische Betrachtungen und Berechnungen der Volumeninkremente manifestiert wird. Im Einklang mit den nach dem Zintl-Konzept zu erwartenden elektronischen Eigenschaften ist Na16(RbRb6)Sb7 ein diamagnetischer Halbleiter mit Eg = 0,33 eV und χmol = -508 × 10-6 cm3 mol-1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...