Dinuclear Face‐Sharing Bi‐octahedral Tungsten(VI) Core and Unusual Thermal Behavior in Complex Th Tungstates. Issue 21 (27th March 2015)

• Record Type: Journal Article
• Authors: Xiao, Bin; Gesing, Thorsten M.; Robben, Lars; Bosbach, Dirk; Alekseev, Evgeny V.
• Is Part Of: Chemistry. Volume 21:Issue 21(2015)
• Page Start: 7746
• Page End: 7754
• Publication Date: 2015-03-27
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201500500
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Two new thorium tungstates A<sub>6</sub>Th<sub>6</sub>(WO<sub>4</sub>)<sub>14</sub>O (A=K and Rb) were synthesized by high‐temperature solid‐state reactions. The structures of both phases are based on a rare dinuclear confacial bi‐octahedral [W<sub>2</sub>O<sub>9</sub>]<sup>6−</sup> core, encapsulated in a [Th<sub>6</sub>W<sub>7</sub>O<sub>46</sub>(W<sub>2</sub>O<sub>9</sub>)]<sup>32−</sup> cage showing a cross‐section geometry similar to a six‐leafed lily. The adjacent cages are connected in two dimensional layers by WO<sub>4</sub> tetrahedral linkers. Due to the dissimilarities in mutual orientations of adjacent layers in these two structures, K<sub>6</sub>Th<sub>6</sub>(WO<sub>4</sub>)<sub>14</sub>O crystallizes in space group of <italic>R</italic>32 while Rb<sub>6</sub>Th<sub>6</sub>(WO<sub>4</sub>)<sub>14</sub>O stabilizes in <italic>P</italic><inline-formula><alternatives><tex-math notation="tex"><![CDATA[$\bar 6$]]></tex-math><inline-graphic xlink:href="ark:/27927/pgjkz2nb3t" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></alternatives></inline-formula>2<italic>c</italic>. The high‐temperature phase transition was observed in Rb<sub>6</sub>Th<sub>6</sub>(WO<sub>4</sub>)<sub>14</sub>O and investigated using high‐temperature PXRD technique. The results demonstrate a very unusual thermal behavior of this compound. The Raman and IR spectra of both phases were analyzed with respect to their complex structures.</p> </abstract>