Javascript är avstängt eller blockerat i din webbläsare. Detta kan leda till att vissa delar av vår webbplats inte fungerar som de ska. Sätt på javascript för optimal funktionalitet och utseende.

Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Johnsson

Mats Johnsson

Universitetslektor

Johnsson

Single-crystal X-ray study of Ba2Cu2Te 4O11Br2 and its incommensurately modulated superstructure companion

Författare

  • Rie Fredrickson Takagi
  • Mats Johnsson
  • Sven Lidin

Summary, in English

Compounds containing lone-pair elements such as TeIV are very interesting from the structural point of view, as the lone-pair nonbonding regions create low-dimensional geometrical arrangements. We have synthesized two new compounds with these features - Ba2Cu2Te 4O11Br2 (I) and Ba2Cu 2Te4O11-δ(OH)Br 2 (II, δ ≈ 0.57) - as members of the AE-M-Te-O-X (AE = alkaline-earth metal, M = transition metal, X = halide) family of compounds by solid-state reactions. Preliminary single-crystal X-ray analysis indicated that compound I crystallizes in the orthorhombic system, but attempts at refinement proved unsatisfactory. Closer inspection of the reciprocal lattice revealed systematic, non-crystallographic absences that indicate twinning. The structure is in fact triclinic, space group C1̄ (equivalent to P1̄), with unit cell parameters (at 120 K) of a= 10.9027(9), b = 15.0864(7), c = 9.379(2) Å, β=106.8947°. It is layered and built from [TeO3E] tetrahedra, [TeO3+1E] trigonal bipyramids (where E is the lone pair of TeIV), [CuO4] squares and irregular [BaO 10Br] polyhedra. The crystal structure of II shows the same basic structure as I but contains additional oxygen, probably in the form of OH groups. The presence of satellites reveals that ordering on this O site creates an incommensurate modulation, primarily affecting Br and Te. The modulated structure of II was solved in the triclinic superspace group X1̄(αβγ)0 with the vector q ≈ 1/16 c*.

Publiceringsår

2008-04-07

Språk

Engelska

Sidor

3434-3441

Publikation/Tidskrift/Serie

Chemistry - A European Journal

Volym

14

Issue

11

Dokumenttyp

Artikel i tidskrift

Förlag

Wiley-VCH Verlag

Nyckelord

  • Alkaline earth metals
  • Layered compounds
  • Solid-state reactions
  • Structure elucidation
  • Tellurium

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0947-6539