ISSN:
0044-2313
Keywords:
Alkali metal hydrogensulfides
;
preparation
;
differential scanning calorimetry
;
crystal structures
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Dynamical Behaviour of Linear Molecular Anions in the Hydrogensulfides of Sodium, Potassium and Rubidium: Differential Scanning Calorimetry, X-ray and Neutron DiffractionHydrogensulfides of the alkali metals M ≅ Na, K, Rb were prepared in autoclaves by the reaction of the corresponding metals with H2S and D2S, respectively, in the temperature range from 50°C to 150°C. Differential scanning calorimetry, X-ray and neutron diffraction methods reveal that both, the HS--and DS--compounds occur in three crystalline modifications with HT ≅ high-, MT ≅ medium- and LT ≅ low-temperature form: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} {\rm HT\hspace{-3pt}: Fm3m, Z = 4} \\ \qquad{\rm NaDS\quad a = 6.056(5) }\mathop {\rm A}\limits^\circ {\rm \,\,at\,\, 433\, K} \\ \qquad{\rm KDS{\hphantom{a}}\quad a = 6.682(4) }\mathop {\rm A}\limits^\circ {\rm \,\,at\,\, 453\, K} \\ \qquad{\rm RbDS\quad a = 6.978(7)}\mathop {\rm A}\limits^\circ {\rm \,\,at\,\, 440\, K} \\ {\rm MT\hspace{-3pt}: R}\overline {\rm 3} {\rm, Z = 3} \\ \qquad{\rm NaDS \quad a = 4.499(5) }\mathop {\rm A}\limits^\circ {\rm,\, c = 9.177(5) }\mathop {\rm A}\limits^\circ {\rm \,\,at\,\, 298\, K} \\ \qquad{\rm RbDS \quad a = 5.188(8) }\mathop {\rm A}\limits^\circ {\rm,\, c = 10.285(9) }\mathop {\rm A}\limits^\circ {\rm \,\,at\,\, 298\, K} \\ {\rm TT\hspace{-3pt}: P2}_{\rm 1} {\rm /m, Z = 2} \\ \qquad{\rm NaDS \quad a = 3.911(1) }\mathop {\rm A}\limits^\circ {\rm,\, b = 4.447(1) }\mathop {\rm A}\limits^\circ {\rm,\, c = 5.930(2) }\mathop {\rm A}\limits^\circ,\,\beta {\rm = 99.55(2)}^\circ {\rm \,\,at\,\, 9\, K} \\ \qquad{\rm KDS{\hphantom{a}}\quad a = 4.309(2) }\mathop {\rm A}\limits^\circ {\rm,\, b = 4.908(2) }\mathop {\rm A}\limits^\circ {\rm,\, c = 6.544(3) }\mathop {\rm A}\limits^\circ,\,\beta {\rm = 100.83(3)}^\circ {\rm \,\,at\,\, 10\, K} \\ \qquad{\rm RbDS \quad a = 4.515(2) }\mathop {\rm A}\limits^\circ {\rm,\, b = 5.116(2) }\mathop {\rm A}\limits^\circ {\rm,\, c = 6.815(3) }\mathop {\rm A}\limits^\circ,\,\beta {\rm = 101.67(2)}^\circ {\rm \,\,at\,\, 10\, K} \\ \end{array}$$\end{document}$$\end{document} The temperatures and enthalpies for the changes of modifications of the H- and D-compounds are given and the atomic arrangements revealed mainly by neutron diffraction data are discussed, in relation to, for example, size of cations.
Notes:
Durch Umsetzung der Alkalimetalle M ≅ Na, K und Rb mit H2S bzw. D2S in Autoklaven bei Temperaturen zwischen 50°C und 150°C wurden die entsprechenden Hydrogensulfide MHS bzw. MDS dargestellt. Differential-Scanning-Kalorimetrie, Röntgen- und Neutronenbeugung belegen für die HS--bzw. DS--Verbindungen jeweils drei kristalline Modifikationen mit HT ≅ Hoch-, MT ≅ Mittel- und TT ≅ Tieftemperaturform: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} {\rm HT\hspace{-3pt}: Fm3m, Z = 4} \\ \qquad{\rm NaDS\quad a = 6,056(5) }\mathop {\rm A}\limits^\circ {\rm \,\,{bei}\,\, 433\, K} \\ \qquad{\rm KDS{\hphantom{a}}\quad a = 6,682(4) }\mathop {\rm A}\limits^\circ {\rm \,\,{bei}\,\, 453\, K} \\ \qquad{\rm RbDS\quad a = 6,978(7)}\mathop {\rm A}\limits^\circ {\rm \,\,{bei}\,\, 440\, K} \\ {\rm MT\hspace{-3pt}: R}\overline {3} {\rm, Z = 3} \\ \qquad{\rm NaDS \quad a = 4,499(5) }\mathop {\rm A}\limits^\circ {\rm,\, c = 9,177(5) }\mathop {\rm A}\limits^\circ {\rm \,\,{bei}\,\, 298\, K} \\ \qquad{\rm RbDS \quad a = 5,188(8) }\mathop {\rm A}\limits^\circ {\rm,\, c = 10,285(9) }\mathop {\rm A}\limits^\circ {\rm \,\,{bei}\,\, 298\, K} \\ {\rm TT\hspace{-3pt}: P2}_{\rm 1} {\rm /m, Z = 2} \\ \qquad{\rm NaDS \quad a = 3,911(1) }\mathop {\rm A}\limits^\circ {\rm,\, b = 4,447(1) }\mathop {\rm A}\limits^\circ {\rm,\, c = 5,930(2) }\mathop {\rm A}\limits^\circ,\,\beta {\rm ={\hphantom{0}}99,55(2)}^\circ {\rm \,\,{bei}\,\, 9\, K} \\ \qquad{\rm KDS{\hphantom{a}}\quad a = 4,309(2) }\mathop {\rm A}\limits^\circ {\rm,\, b = 4,908(2) }\mathop {\rm A}\limits^\circ {\rm,\, c = 6,544(3) }\mathop {\rm A}\limits^\circ,\,\beta {\rm = 100,83(3)}^\circ {\rm \,\,{bei}\,\, 10\, K} \\ \qquad{\rm RbDS \quad a = 4,515(2) }\mathop {\rm A}\limits^\circ {\rm,\, b = 5,116(2) }\mathop {\rm A}\limits^\circ {\rm,\, c = 6,815(3) }\mathop {\rm A}\limits^\circ,\,\beta {\rm = 101,67(2)}^\circ {\rm \,\,{bei}\,\, 10\, K} \\ \end{array} $$\end{document} Umwandlungstemperaturen und -enthalpien der H- und D-Verbindungen werden mitgeteilt und die vorwiegend aus Neutronenbeugungsdaten von Deuterosulfiden ermittelten Atomanordnungen u.a. in Abhängigkeit von der Größe der Kationen diskutiert.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19915980117
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