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  • 1995-1999  (2)
  • 1965-1969
  • [FeO5] square pyramide  (1)
  • di-sodium cobalt vanadium hepta-fluoride  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 1573-1581 
    ISSN: 0044-2313
    Keywords: Weberite structure ; structure determination ; di-sodium iron vanadium hepta-fluoride ; di-sodium iron chromium hepta-fluoride ; di-sodium cobalt vanadium hepta-fluoride ; disodium cobalt chromium hepta-fluoride ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure Determinations of Four Monoclinic Weberites Na2MIIMIIIF7 (MII = Fe, Co; MIII = V, Cr)By solid state reaction of the binary fluorides single crystals of the following weberites were prepared and their monoclinic structure (space group C2/c, Z = 16) determined by X-ray methods: Na2FeVF7 (a = 1 271.0(3), b = 742.9(1), c = 2 471.6(5) pm, β = 100.03(3)°; R1 = 0.043 (1 545 Reflexe); Fe—F = 203.8, V—F = 193.0 pm); Na2FeCrF7 (a = 1 262.5(3), b = 739.1(1), c = 2 460.5(5) pm, β = 99.93(3)°; R1 = 0.029 (2 340); Fe—F = 203.6, Cr—F = 190.5 pm); Na2CoVF7 (a = 1 270.3(5), b = 739.1(3), c = 2 465.1(10) pm, β = 100.02(3)°; R1 = 0.028 (2 250); Co—F = 201.6, V—F = 193.6 pm); Na2CoCrF7 (a = 1 257.8(3), b = 733.5(1), c = 2 441.5(5) pm, β = 99.64(3)°; R1 = 0.030 (2 227); Co—F = 201.2, Cr—F = 190.2 pm). Concerning the above average distances within the distorted [MF6] octahedra and the shape of [NaF8] coordination details are given and discussed.
    Notes: Durch Festkörperreaktion der binären Fluoride wurden Einkristalle der folgenden Weberite dargestellt und röntgenographisch deren monokline Struktur bestimmt (Raumgruppe C2/c, Z = 16): Na2FeVF7 (a = 1 271,0(3), b = 742,9(1), c = 2 471,6(5) pm, β = 100,03(3)°; R1 = 0,043 (1 545 Reflexe); Fe—F = 203,8, V—F = 193,0 pm); Na2FeCrF7 (a = 1 262,5(3), b = 739,1(1), c = 2 460,5(5) pm, β = 99,93(3)°; R1 = 0,029 (2 340); Fe—F = 203,6, Cr—F = 190,5 pm); Na2CoVF7 (a = 1 270,3(5), b = 739,1(3), c = 2 465,1(10) pm, β = 100,02(3)°; R1 = 0,028 (2 250); Co—F = 201,6, V—F = 193,6 pm); Na2CoCrF7 (a = 1 257,8(3), b = 733,5(1), c = 2 441,5(5) pm, β = 99,64(3)°; R1 = 0,030 (2 227); Co—F = 201,2, Cr—F = 190,2 pm). Zu den genannten mittleren Abständen in den verzerrten [MF6]-Oktaedern und zur Form der [NaF8]-Koordination werden Einzelheiten mitgeteilt und diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1048-1054 
    ISSN: 0044-2313
    Keywords: Structure determination ; [FeO5] square pyramide ; asymmetric [PbO6] coordination ; lone pair effect ; perovskite relation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Lead Strontium Ferrate(III): The Crystal Structure of the Phase Pb4Sr2Fe6O15At orthorhombic single crystals of Pb4Sr2Fe6O15 (a = 568.73(8), b = 392.03(4), c = 2107.5(3) pm; Z = 4/3, space group Pnma) a X-ray structure determination has been performed (R1 = 0,036 for 488 „observed“ resp. wR2 = 0,073 for all 643 independent reflexions). It revealed a framework of polyhedra related to perovskite, in which chains of edgesharing pyramids [FeO5] (average Fe1—O: 197 pm; Fe1—Fe1: 305.5 pm) are linked via apices with corner-sharing [FeO6] octahedra (Fe2—O: 201 pm). 12-fold, strongly distorted cuboctahedrally coordinated „perovskite positions“ show mixed occupancy by 2/3 Sr + 1/3 Pb (= Sr2; Sr2—O: 287 pm). More spacy channels, running parallel to the chains of pyramids along [010] of the structure, contain lead atoms only. The double occupancy of the corresponding cages results in short distances Pb1—Pb1 (355.9 pm) and Pb1—Fe2 (314.4 pm), as well as in a very asymmetric [PbO6] coordination (Pb1—O: 253 pm), in the opposite hemisphere of which the lone electron pair s2 is supposed to be located. Details are communicated and structural relations discussed.
    Notes: An orthorhombischen Einkristallen von Pb4Sr2Fe6O15 (a = 568,73(8), b = 392,03(4), c = 2107,5(3) pm; Z = 4/3, Raumgruppe Pnma) wurde eine Röntgenstrukturbestimmung durchgeführt (R1 = 0,036 für 488 „beobachtete“ bzw. wR2 = 0,073 für alle 643 unabhängigen Reflexe). Diese ergab ein perowskitverwandtes Polyedergerüst, in dem Ketten kantenverknüpfter [FeO5]-Pyramiden (Mittelwert Fe1—O: 197 pm; Fe1—Fe1: 305,5 pm) mit ihrerseits eckenverknüpften [FeO6]-Oktaedern (Fe2—O: 201 pm) über Ecken verbunden sind. Zwölffach, stark verzerrt kuboktaedrisch koordinierte „Perowskit-Positionen“ sind gemischt besetzt mit 2/3 Sr + 1/3 Pb (= Sr2; Sr2—O: 287 pm). Dagegen befinden sich in größeren Kanälen, die sich parallel zu den Pyramidenketten längs [010] durch die Struktur ziehen, nur Bleiatome. Die doppelte Besetzung der zugehörigen Hohlräume führt zu kurzen Abständen Pb1—Pb1 (355,9 pm) und Pb1—Fe2 (314,4 pm), und zu einer ganz einseitigen [PbO6]-Koordination (Pb1—O: 253 pm). in deren Gegenhemisphäre das s2-Elektronenpaar zu vermuten ist. Einzelheiten werden mitgeteilt und Strukturverwandtschaften diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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