Das erste Alkali-Erdalkalimetall-Oxoniccolat(II,III): NaBa2Ni22+Ni3+O6

The First Alkalinc Alkaline Earth Oxoniccolate(II,III): NaBa₂Ni₂²⁺Ni³⁺O₆ Single crystals of NaBa₂Ni₂²⁺Ni³⁺O₆ were prepared by solid state reaction. X-ray investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.310; b = 11.220; c = 14.397 Å; Z = 8. Na⁺ is coordinated by six O^2? in form of a trigonal prism and the two Ba²⁺ point positions show different coordination numbers C.N. = 6 + 4 and 8. The Ni²⁺ /Ni³⁺ ions are in square planar polygons, six of them are forming a so far unknown closed macro polyhedra.