Struktur des Strontiumvanadiumoxidhydrats, SrV12O27 · 3 H2O: eine Vanadiumoxidbronze mit neuartigem Vanadatgerüst

Abstract

Abstract SrV12O27 · 3 H2O, synthesized hydrothermally. Monoclinic P21/m; a = 11.684(2) Å, b = 11.126(2) Å, c = 9.052(2) Å, β = 110.94(2)°; Z = 2. R(F) = 0.049, RW (F) = 0.039 for 3756 observed reflections. The structure includes a new vanadate framework V4O9, similar to the V2O5 in vanadium bronzes β-A x V2O5. The V4O9 framework, forming a substructure with b′ = b/3, consists of 2 × 3 columns of edge-sharing VO6 octahedra and chains of edge-sharing VO5 trigonal bipyramids. The columns and the chains run parallel to [010] and are connected through common corners of VO6 and VO5. The columns neighbouring in [001] direction share two corners of octahedra per b′ period. The Sr atoms and H2O molecules are accommodated in the wide [010] tunnels characteristic of the V4O9 framework.