ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
The First Mixed-valent Oxoplumbate with Isolated Anions. On KNa7[PbIVO4][PbIIO3]For the first time KNa7Pb2O7 has been prepared by reaction of K and Na Oxides with „PbO2“ rsp. PbOred [e. g.: KO0.48:NaO0.36:„PbO2“ = 1:7:2 (Ag-cylinders, reduced Ar-pressure, sealed in supremax-glas ampoules, 600°C, 14 d): redorange single crystals of plated shape]. The structure determination [3269 Io(hkl), four-circle diffractometer PW 1100 (Fa. Philips), ω-scan, MoKα, R = 9.52%, Rw = 7.67%, absorption not considered] proves the space group P21/c with a = 1758.48(10), b = 596.76(3), c = 1066.46(8) pm, β = 90.682(8)°, Z = 4, dx = 4.311, dpyk = 4.28 g/cm3.The structure is characterized by isolated [PbIVO4] (symmetry nearly Td) and [PbIIO3] groups (symmetry nearly C3v), the latter connected by cations to double-layers.The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.
Notes:
Neu dargestellt wurde KNa7Pb2O7 durch Reaktion von K- und Na-Oxiden mit „PbO2“ bzw. PbOrot [z. B.: KO0,48:NaO0,36: „PbO2“ = 1:7:2 (Ag-Bömbchen, verminderter Ar-Druck, Supremaxglasampulle, 600°C, 14 d ): Rotorange Einkristalle von tafelförmigem Habitus]. Die Strukturaufklärung [3269 Io(hkl), Vierkreisdiffraktometer PW 1100 (Fa. Philips), ω-scan, MoKα, R = 9,52%, Rw = 7,67%, Absorption nicht berücksichtigt] belegt die Raumgruppe P21/c-C2h5 mit a = 1758,48(10), b = 596,76(3), c = 1066,46(8) pm, β = 90,682(8)°, Z = 4, drö = 4,311, dpyk = 4,28 g/cm3, Parameter siehe Text.Die Struktur ist charakterisiert durch „isolierte“ [PbIVO4]- (Symmetrie annähernd Td) und [PbIIO3]-Gruppen (Symmetric annähernd C3v), wobei letztere über gemeinsame Kationen zu Doppelschichten verknüpft sind.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, werden berechnet und diskutiert.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19875490611
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