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The new ternary phosphide La2Ni12P5 has been prepared by direct arc melting of the components as pure metals and red phosphorus. The crystal structure has been determined using X-ray single crystal diffraction data. The compound exhibits a new type of crystal structure, P21/m with lattice parameters a = 10.911(3), b = 3.696(2), c = 13.174(4) A, β = 108.02(2)°, V = 505,2(6) A3, Z = 2. Atomic parameters least squares refinement of 116 independent variables (anisotropic approximation for thermal vibrations) employed 1 284 independent Io(hkl); RF = 0.0278 and RW = 0.0287. The crystal structure is characterized by trigonal prismatic arrangement of phosphorus atoms stacking variant of infinite (with phosphorus centered) columns built by metal trigonal prisms ‖ [010]. Two or three such columns are connected through common edges (lanthanum atoms). The compounds RE2Ni12P5 (where RE = Ce, Pr, Nd and Eu) display the same with La2Ni12P5 crystal structure. Lattice parameters of these compounds have been refined using powder diffraction data. Darstellung und Kristallstruktur von La2Ni12P5 und isotypen ternaren Lanthanoid–Nickel-Phosphiden Das neue ternare Phosphid La2Ni12P5 wurde durch Aufschmelzen reiner Komponenten in einem Lichtbogenofen synthetisiert und seine Kristallstruktur durch Einkristalldaten belegt. La2Ni12P5 ist ein erster Vertreter eines neuen Strukturtyps: Raumgruppe P21/m, a = 10,911(3), b = 3,696(2), c = 13,174(4) A, β = 108,02(2)°, V = 505,2(6) A3, Z = 2. Die Lageparameter wurden “anisotrop” aus 1 284 Io(hkl) zu RF = 0,0278, RW = 0,0287 (I > 3sI; 116 Parameter) verfeinert. Charakteristisch fur den Aufbau ist die trigonal-prismatische Koordination der Phosphoratome. Die isotypen Phosphide Ln2Ni12P5 (Ln = Ce, Pr, Nd und Eu) wurden ebenfalls dargestellt und durch Pulverdaten charakterisiert. |
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