A new compound β-Tl6Si2O7 has been investigated using the methods of IR spectroscopy and microprobe and X-ray diffraction analysis. The elementary unit parameters were as follows: P6 3/m, a = 9.673(2) Å, c = 3.9169(9) Å, and V = 317.4(1) Å3. The structure was resolved by direct methods and corrected until R 1 = 0.029 (wR 2 = 0.047) for 240 reflections [F o] ≥ 4σ F . The crystal structure of β-Tl6Si2O7 contains one symmetrically independent position of the Tl+ cation that forms three short (Tl-O = 2.54 Å) bonds and one weak bond (2.93 Å) with the oxygen atom. One can observe a strong disordering of silicon atoms (Si-Si = 0.64 Å). The distorted tetragonal pyramids TlO4 are linked through silicate tetrahedra into a three-dimensional framework. The interesting feature of the crystal structure of β-Tl6Si2O7 is in the presence of wide channels occupied by lone electron pairs on Tl+ cations. One can also mention that in most of the structures of Tl+ oxygen-containing salts the lone pairs are associated into separate parts in the form of micelles in channels of frameworks or other structural cavities.

Original languageEnglish
Pages (from-to)473-477
Number of pages5
JournalGlass Physics and Chemistry
Volume38
Issue number6
DOIs
StatePublished - Nov 2012

    Scopus subject areas

  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

    Research areas

  • lone electron pair, silicates, thallium, thallium oxosalts, X-ray structural analysis

ID: 9144877