ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
1. K and Rb amide crystallize as their low-temperature modifications monoclinic with the following lattice constants: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} \alpha - {\rm KNH}_{\rm 2} :\quad {\rm a} = 4,58_6 \,{\rm \AA},\quad {\rm b} = 3,90_4 \,{\rm \AA}, \quad {\rm c} = 6,22_3 \,{\rm \AA},\quad \beta = 95^\circ {48}^\prime; \\ \alpha {\rm - RbNH}_{2} :\quad {\rm a} = 4,85_0 \,{\rm \AA},\quad {\rm b} = 4,14_8 \,{\rm \AA},\quad {\rm c} = 6,40_2 \,{\rm \AA},\quad \beta = 95^\circ {48}^\prime \\ \end{array}. $$\end{document} The unit cell contains two molecules. The space group is: C2h2, position 2(e)2. The resulting structures are to be regarded as deformed sodium chloride type. The high-temperature modifications crystallize in the sodium chloride structure. The monoclinic deformation occurs by the fixation of the NH2- dipole-anion, which is allowed to rotate in the β-modification
Notes:
1. Kalium- und Rubidiumamid kristallisieren in ihren Tieftemperaturmodifikationen monoklin mit den Gitterkonstanten: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} \alpha - {\rm KNH}_{\rm 2} :\quad {\rm a} = 4,58_6 \,{\rm \AA},\quad {\rm b} = 3,90_4 \,{\rm \AA}, \quad {\rm c} = 6,22_3 \,{\rm \AA},\quad \beta = 95^\circ {48}^\prime \\ \alpha {\rm - RbNH}_{2} :\quad {\rm a} = 4,85_0 \,{\rm \AA},\quad {\rm b} = 4,14_8 \,{\rm \AA},\quad {\rm c} = 6,40_2 \,{\rm \AA},\quad \beta = 95^\circ {48}^\prime \\ \end{array} $$\end{document}. In der Elementarzelle sind zwei Formeleinheiten; Raumgruppe: C2h2, Punktlage 2 (e).2. Die ermittelten Strukturen sind als Deformierung der Hochtemperaturmodifikationen, die im Natriumchloridgitter kristallisieren, anzusehen. Die monokline Verzerrung tritt durch die Fixierung des NH2- -Dipolanions ein, das in der β-Modifikation frei rotiert.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19653380309
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