Z. Naturforsch. 2013, 68b, 871 – 876
One-dimensional Gold Clusters in HP-Ce7Au13+xGe10−x
Gunter Heymann1, Birgit Heying2, Jan F. Riecken2, Hubert Huppertz1, and Rainer Pöttgen2
1 Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80–82, A-6020 Innsbruck, Austria
2 Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstrasse 30, 48149 Münster, Germany
Reprint requests to R. Pöttgen. E-mail: pottgen@uni-muenster.de
Received June 18, 2013 / published online July 25, 2013
Single crystals of the high-pressure phase Ce7Au13+xGe10−x were obtained by treating CeAuGe at 9.5 GPa and 1473–1523 K in a multi-anvil press. The structure of Ce7Au13.35Ge9.65 was refined on the basis of single-crystal X-ray diffractometer data: new type, Pbam, a = 1571.9(3), b = 1780.3(4), c = 443.58(9) pm, wR2 = 0.0470, 2017 F2 values, 96 variables. Two of the five germanium sites show a small degree of Ge/Au mixing. The gold and germanium atoms build up a complex three-dimensional, covalently bonded [Au13.35Ge9.65] network with Au–Ge distances ranging from 249 to 293 pm. The [Au13.35Ge9.65] network also exhibits a one-dimensional gold cluster with Au–Au distances of 275–301 pm and a weakly bonded germanium dumb-bell with a Ge4–Ge5 bond length of 271 pm. The four crystallographically independent cerium atoms fill cavities of coordination numbers 19 and 20 within the [Au13.35Ge9.65] network. These coordinations are known from other structure types. Consequently one can describe the Ce7Au13.35Ge9.65 structure as an intergrowth variant of EuAuGe, HP-CeAuGe (TiNiSi), CeAu2Ge2 (CePt2Ge2), and Ce3Ag4Ge4 (Gd3Cu4Sn4) related slabs.
Key words: High-pressure Synthesis, Cerium, Germanide, Crystal Structure, Gold
Full-text PDF