TlCu5O(VO4)3 mit KCu5O(VO4)3‐Struktur – ein Thallium‐kupfer(II)‐oxidvanadat als Oxidationsprodukt einer Tl/Cu/V‐Legierung

TlCu₅O(VO₄)₃ with KCu₅O(VO₄)₃ Structure – a Thallium Copper(II) Oxide Vanadate as an Oxidation Product of a Tl/Cu/V Alloy Brown‐black crystals of the new oxide vanadate TlCu₅O(VO₄)₃ (triclinic, P1, a = 610.4(1) pm, b = 828.9(1) pm, c = 1075.3(1) pm, α = 97.70(1)°, β = 92.25(1)°, γ = 90.28(1)°, Z = 2) were obtained as a byproduct during the reaction of a Tl/Cu/V alloy with oxygen. The compound is isotypic with KCu₅O(VO₄)₃. All the crystals investigated were twins by non‐merohedry with 100] as the twin axis. The structure contains ladder shaped Cu₁₀O₂₆]‐ribbons composed of edge‐ and corner‐sharing CuO₅]‐polyhedra (tetragonal pyramids and trigonal bipyramids) and linked by vanadate groups. The thallium ions fill channels running along the a axis. No stereochemical activity of the thallium(I)‐lone pair is observed.