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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 600 (1991), S. 239-248 
    ISSN: 0044-2313
    Keywords: Cyano-elpasolites ; bis(-tetramethylammonium) alkali hexacyanometallates ; preparation ; crystal structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetragonal Cyano-Elpasolites: The Crystal Structures of [N(CH3)4]2KMn(CN)6 and [N(CH3)4]2RbCo(CN)6The tetragonal bis(-tetramethylammonium)-alkali-hexacyanometallates [N(CH3)4]2KMn(CN)6 (a = 884.8(2), c = 1222.2(6) pm) and [N(CH3)4]2RbCo(CN)6 (a = 884.7(1), c = 1233.1(2) pm) were prepared in the form of single crystals and their structures determined by X-ray methods (wR = 0.050 and 0.047 for 486 and 463 independent reflections, respectively; space group 14/m, Z = 2). The average distances in the resulting elpasolite structure, which is but slightly tetragonally distorted by small ferro-rotative displacements of the [M(CN6]3-) octahedra (Mn—C = 201.8, C—N = 115.6, K—N = 307.1 pm resp. Co—C = 190.7, C—N = 114.8, Rb—N = 320.1 pm), seem a bit enlarged if compared to related cyano complexes. Reasons for this are discussed using a tolerance factor concept for cyanoepasolites.
    Notes: Die tetragonalen Bis(-tetramethylammonium)-Alkali-Hexacyanometallate [N(CH3)4]2KMn(CN)6 (a = 884.8(2), c = 1222,2(6) pm) und [N(CH3)4]2RbCo(CN)6 (a = 884,7(1), c = 1233,1(2) pm) wurden in Form von Einkristallen dargestellt und röntgenographisch ihre Strukturen bestimmt (wR = 0,050 bzw. 0,047 für 486 bzw. 463 unabhängige Reflexe; Raumgruppe 14/m, Z = 2). Die mittleren Abstände in der resultierenden Elpasolithstruktur, die durch geringe ferrorotative Drehung der [M(CN)6]3--Oktaeder nur wenig tetragonal verzerrt ist (Mn—C = 201,8, C—N = 115,6, K—N = 307,1 pm bzw. Co—C = 190,7, C—N = 114,8, Rb—N = 320,1 pm), erscheinen leicht vergrößert im Vergleich zu Werten die in verwandten Cyanokomplexen beobachtet wurden. Gründe dafür werden im Rahmen einer Toleranzfaktorbetrachtung für Cyano-Elpasolithe 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 595 (1991), S. 139-149 
    ISSN: 0044-2313
    Keywords: Cesium copper(II) fluoride, CsCu2F5 ; crystal structure ; magnetism ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure of Cesium-containing Fluorides. IX. CsCu2F5, a Compound exhibiting Coordination Numbers 4, 5, and 6 for Copper(II)Single crystals of the monoclinic compound CsCu2F5 (a = 713.5, b = 738.6, c = 950.2 pm, β = 97.19°; P21/n, Z = 4) were prepared and their structure determined by X-ray methods (wR = 0.045 for 2140 independent reflections). Besides of square planar and elongated octahedral [CuFn] units (average Cu—F = 190.3 resp. 195.0/221.9 pm), the structure exhibits the first example of [CuF5] coordination, which is a distorted square pyramide (Cu—F = 190.7/221.6 pm). Relations to the pyrochlore structure are discussed, as well as the linking of polyhedra and the bridge angles Cu—F—Cu in context with the antiferromagnetic properties (TN = 54 K), which were found by powder susceptibility measurements.
    Notes: Einkristalle der monoklinen Verbindung CsCu2F5 (a = 713,5, b = 738,6, c = 950,2 pm, β = 97,19°; P21/n, Z = 4) wurden dargestellt und ihre Struktur röntgenographisch bestimmt (wR = 0,045 für 2140 unabhängige Reflexe). Neben quadratisch planaren und gestreckt oktaedrischen [CuFn]-Baugruppen (Mittelwerte Cu—F = 190,3 bzw. 195,0/221,9 pm) zeigt die Struktur das erste Beispiel einer [CuF5]-Koordination in Form einer verzerrten quadratischen Pyramide (Cu—F = 190,7/221,6 pm). Beziehungen zur Pyrochlorstruktur werden diskutiert, sowie die Vernetzung der Polyeder und die Brückenwinkel Cu—F—Cu im Zusammenhang mit den antiferromagnetischen Eigenschaften (TN = 54 K), die durch Suszeptibilitätsmessungen an Pulvern ermittelt wurden.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1614-1620 
    ISSN: 0044-2313
    Keywords: Structure determination ; vanadium weberites ; disodium metal(II) vanadium(III) heptafluorides ; sodium tetrafluoro-vanadate(III) ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structures of the Vanadium Weberites Na2MIIVIIIF7 (MII = Mn, Ni, Cu) and of NaVF4At single crystals of the vanadium(III) compounds NaVF4 (a = 790.1, b = 531.7, c = 754.0 pm, β = 101.7°; P21/c, Z = 4), Na2NiVF7 (a = 726.0, b = 1031.9, c = 744.6 pm; Imma, Z = 4) and Na2CuVF7 (a = 717.6, b = 1043.5, c = 754.6 pm; Pmnb, Z = 4) X-ray structure determinations were performed, at Na2MnVF7 (a = 746.7, c = 1821.6 pm; P3221, Z = 6) a new refinement. NaVF4 crystallizes in the layer structure type of NaNbO2F2. The fluorides Na2MIIVF7 represent new orthorhombic (MII = Ni; Cu) resp. trigonal (MII = Mn) weberites. The average distances within the [VF6] octahedra of the four compounds are in good agreement with each other and with data of related fluorides (V—F: 193.3 pm). The differences between mean bond lengths of terminal and bridging F ligands are 5% in NaVF4, but less than 1% in the weberites. Details and data for comparison are discussed.
    Notes: An Einkristallen der Vanadium(III)-Verbindungen NaVF4 (a = 790,1, b = 531,7, c = 754,0 pm, β = 101,7°; P21/c, Z = 4), Na2NiVF7 (a = 726,0, b = 1031,9, c = 744,6 pm; Imma, Z = 4) und Na2CuVF7 (a = 717,6, b = 1043,5, c = 754,6 pm; Pmnb, Z = 4) wurden Röntgenstrukturbestimmungen durchgeführt, an Na2MnVF7 (a = 746,7, c = 1821,6 pm; P3221, Z = 6) eine neue Verfeinerung. NaVF4 kristallisiert in der Schichtstruktur des NaNbO2F2-Typs. Die Fluoride Na2MIIVF7 sind neue orthorhombische (MII = Ni; Cu) bzw. trigonale (MII = Mn) Weberit-Vertreter. Die mittleren Abstände in den [VF6]-Oktaedern der vier Verbindungen stimmen gut miteinander und mit Daten in verwandten Fluoriden überein (V—F: 193,3 pm). Die Unterschiede zwischen den mittleren Abständen terminaler und verbrückender F-Liganden betragen in NaVF4 5%, in den Weberiten aber weniger als 1%. Einzelheiten und Vergleichsdaten werden diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    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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