Synthese und Struktur einer neuen Form von CuYMo2O8

Synthesis and Structure of a New form of CuYMo₂O₈ Single crystals of a new form of CuYMo₂O₈ were prepared and investigated by X-ray diffractometer technique [space group D-Pbca; a = 10.160 Å, b = 9.701 Å, c = 14.527 Å; Z = 8]. CuYMo₂O₈ represents a new structure type characterised by MoO₄-tetrahedrons, Cu⁺ with coordination number 2 + 1 and square antiprisms around Y³⁺. The crystal structure and the Cu⁺ coordination are discussed.     

Synthese und Kristallstruktur einer neuen Modifikation von Tetraselentetranitrid,Se4N4

Synthesis and Crystal Structure of a New Modification of Tetraselenium Tetranitride, Se₄N₄ β-Se₄N₄ has been prepared by the reaction of selenium dioxide with the phosphane imine Me₃SiNPMe₃ in acetonitrile, forming red-brown crystal needles. The crystal structure analysis shows a new modification, the IR spectrum of which differs only slightly from the known α-form of Se₄N₄ (space group C2/c). β-Se₄N₄: Space group P2₁/n, Z = 4, structure solution with 1 667 observed unique reflections, R = 0.054. Lattice dimensions at ?50°C: a = 881.8(2), b = 738.7(2), c = 899.6(2) pm, β = 93.58(1)°. Just as the α-form β-Se₄N₄ forms cage molecules without symmetry and intramolecular Se? Se contacts of 273.2 and 274.0 pm. There are strong Se…?N-interactions between the Se₄N₄ molecules.     

Synthese und Struktur einer neuen Form von CuNdW2O8: β-CuNdW2O8

Synthesis and Structure of a New Form of CuNdW₂O₈: β-CuNdW₂O₈ Single crystals of an unknown form of CuNdW₂O₈ were prepared and investigated by X-ray diffractometer technique [space group C? P₁; a = 6.1330; b = 6.0760; c = 5.0190 Å; α = 111.79°; β = 93.24°; γ = 111.20°; Z = 1]. β-CuNdW₂O₈ represents a new structure type characterized by WO₆ octahedral chains and O? Cu? O dumbbells. Its structure is discussed in respect to other copper tungstates.