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

SrV12O27. 3 H2O, synthesized hydrothermally. Monoclinic P2(1)/m; a = 11.684(2) Angstrom, b = 11.126(2) Angstrom, c = 9.052(2) Angstrom, beta = 110.94(2)degrees; Z = 2. R(F) = 0.049, R-w(F) = 0.039 for 3756 observed reflections. The structure includes a new vanadate framework V4O9, Similar to the V2O5 in vanadium bronzes beta-A(x)V(2)O(5). The V4O9 framework, forming a substructure with b' = b/3, consists of 2 x 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.