| Autor: |
Schäfer, Marion C., Nikelski, Tanja, Schleid, Thomas |
| Zdroj: |
Zeitschrift für Kristallographie - Crystalline Materials; September 2013, Vol. 228 Issue: 9 p483-488, 6p |
| Abstrakt: |
AbstractThe here reported compounds of the isotypic series Ln4O4Cl[BO3] with Ln = Eu-Tm represent the first type of oxide chloride oxoborates with trivalent lanthanoid cations. They crystallize monoclinically with the space group P21/n and four formula units per unit cell. The cell dimensions range from a = 878.21(6), b = 818.42(5), c = 1091.50(7) pm, β = 101.49(1)º for Eu4O4Cl[BO3] to a = 847.08(6), b = 795.23(5), c = 1083.16(7) pm, β = 103.64(1)º for Tm4O4Cl[BO3] and are in good agreement with the lanthanoid contraction. The basic building blocks of this structure consist of O2- -centered (Ln3+)4tetrahedra ([OLn4]10+) linked first via common edges to 1 ∞{[O12Ln10]6+} double chains running along the [010] direction. Their further fusion again via shared edges leads to highly corrugated 2∞{[O4Ln4]4+} layers spreading out parallel to the (101) plane. These layers are held together by isolated [BO3]3-triangles and Cl-anions. The four crystallographically different Ln3+cations show seven or eight O2-and Cl-anions in their coordination spheres. |
| Databáze: |
Supplemental Index |
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