Ein neues metastabiles Zinkoxovanadat: Zn4V2O9

For the first time Zn₄V₂O₉ was prepared and investigated by single crystal X-ray methods. The metastable compound exists between a CO₂-Laser generated flux and the solid ZnO/V₂O₅ material. The quenched light brown crystals show a monoclinic symmetry (space group C ₂ ² —P2₁,a=10.488 (5),b=8.198 (6),c=9.682 (5) Å; =118.66 (4)°;Z=4]. Zn₄V₂O₉ has a characteristic Zn/O-framework with incorporated V⁵⁺ in tetrahedral coordination. The relationship to Zn₄Ta₂O₉ and the calculation of the madelung part of lattice energy (MAPLE) in respect to the metastable character are discussed.