An alternative approach to rationalizing the structures of the cyclotrisilicates: Rb10[Si6O17], Cs8[Si6O16] and Na3Y[Si6O15] by viewing them in light of the extended Zintl–Klemm concept. Issue 4 (26th February 2016)

• Record Type: Journal Article
• Authors: Vegas, Ángel
• Is Part Of: Acta crystallographica. Volume 69:Issue 4(2013:Aug.)
• Page Start: 356
• Page End: 361
• Publication Date: 2016-02-26
• Subjects: extended Zintl–Klemm concept -- connectivity -- silicate skeletons
• DOI: 10.1107/S2052519213013183
• Languages: English
• ISSNs: 2052-5206

Abstract

Abstract : The structures of the three dimeric cyclotrisilicate anions [Si6 O17 ] 10−, [Si6 O16 ] 8− and [Si6 O15 ] 6− forming part of the compounds Rb10 [Si6 O17 ] or Rb14 [Si4 ][Si6 O17 ], Cs8 [Si6 O16 ] and Na3 Y[Si6 O15 ], respectively, have been described as different ways of condensing the more elemental cyclotrisilicate anions [Si3 O9 ] 6− [Hlukhyy & Fässler (2013). Z. Anorg. Allg. Chem .639, 231–233]. Such a description prevents a rational explanation of the connectivity between the Si atoms. So, in this article the Si skeletons of the above silicate anions are put on a common basis in light of the extended Zintl–Klemm concept. Their connectivity is directly related to the ratio Ψ‐S/Ψ‐P resulting from the number of electrons transferred from the electropositive Na, Y, Rb and Cs atoms, offering a new example of the fact that there exists a univocal link between chemical composition (in terms of pseudo‐atoms) and structure: the generalized Zintl–Klemm concept. The three skeletons fit the connectivity of hypothetical Zintl polyanions of composition [Ψ‐S4 P2 ] 10–, [Ψ‐S2 P4 ] 8– and [Ψ‐P6 ] 6− respectively.