Zobrazeno 1 - 10
of 74
pro vyhledávání: '"Egbert Keller"'
Autor:
Egbert Keller
Publikováno v:
Zeitschrift für Kristallographie - Crystalline Materials. 231:691-708
Within a “homogeneous” series of (crystal-chemically) isotypic structures one and only one chemical element E of the sum formula is replaced successively by heavier elements of the same group of the periodic table. For corresponding series of “
Autor:
Egbert Keller, Peter Schultz
Publikováno v:
Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials. 70:372-378
Three quasi-binary phase systems, BiSX1 − xYx(X,Y= Cl, Br, I; 0
Publikováno v:
Zeitschrift für Naturforschung B. 68:1288-1294
Attempts to crystallize the sodium chromium alum, NaCr(SO4)2(H2O)12, from water=methanol solutions at temperatures around 281 K yielded crystals of the title compound instead. Their monoclinic structure can be described as a centered rectangular arra
Autor:
Luitgard Rees-Isele, Egbert Keller
Publikováno v:
Zeitschrift für Naturforschung B. 67:1229-1234
The cubic structure of the sodium chromium alum [NaCr(SO4)2(H2O)12] has been published in 1968 with a lattice parameter a which is by 0.17 Å larger than the one of the potassium chromium alum. In order to investigate this “lattice parameter anomal
Publikováno v:
Acta Crystallographica Section C Crystal Structure Communications. 68:i12-i16
The title phase, first detected in the early 1980s but hitherto unpublished, has been resynthesized and structurally characterized. Unambiguous determination of the chemical composition was not possible by structure analysis alone, but required addit
Autor:
Caroline Röhr, Egbert Keller
Publikováno v:
Zeitschrift für Kristallographie - Crystalline Materials. 223:431-440
Structural changes within the isotypic series ABiO2 (A = Na, K, Rb, Cs) and ASbO2 (A = K, Rb, Cs) and between corresponding members of the two series are analyzed after re-determination of the structure of NaBiO2. Despite the low valence of A—O bon
Autor:
Volker Krämer, Egbert Keller
Publikováno v:
Zeitschrift für Naturforschung B. 62:983-987
The crystal structure of the trihydrate of peramivir (C15H28N4O4), a potential influenza A/B and avian-influenza drug, has been determined. The structure, belonging to the tetragonal space group P42212 with Z = 32, a = 27.216(4), c = 23.084(5) Å, V
Publikováno v:
Materials Research Bulletin. 42:1391-1394
The new compounds NaBi6O9X (X = Br, I) were synthesized. Attempts to synthesize the analogous RbBi6O9X (X = Br, I) compounds yielded mixed systems with about 10% of the Rb atoms replaced by Na and K atoms. Another mixed system, Na0.77(3)K0.23(3)Bi6O9
Autor:
Volker Krämer, Egbert Keller
Publikováno v:
Acta Crystallographica Section B Structural Science. 62:417-423
Experimentally determined halide-ion size differences are compared with expected size differences in the three series of isotypic bismuth chalcogenide halide compounds, KBi6O9 X (X = Cl, Br and I), BiOX (X = F, Cl, Br and I) and BiSX (X = Cl, Br and
Autor:
Egbert Keller, Volker Krämer
Publikováno v:
Acta Crystallographica Section B Structural Science. 62:411-416
Expectation values for size differences between pairs of `ions' (atoms in oxidation states ≠ 0) embedded into similar coordination environments are calculated from tables of bond-valence parameters and ionic radii.