Ein Beitrag zur Kristallchemie von Verbindungen mit Johillerit-Struktur: KCo3Cu(As2,58V0,42)O12 / On the Crystal Chemistry of Compounds with Johillerite Structure: KCo3Cu(As2,58V0,42)O12

Abstract

Single crystals of KCo3Cu(As2.58V0.42)O12 were prepared by solid state reactions below the melting point of the reaction mixture (K2CO3, CuO, COC2O4, V2O5 and 3 As2O5 · 5H2O). It crystallizes with monoclinic symmetry, space group C6 2h-C2/c, a = 12.207, b = 12.730, c = 6.811 Å, β = 113.69°, Z = 4. The structure type is characterized by isolated twisted-square CuO4-polygons, CoO6-octahedra and a special 4+4-coordination of the potassium ion. As5+ and V5+ are in tetrahedral coordination with a partly statistical distribution of these ions.