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Updated: Apr 9, 2026
Synthesis of Nine-atom Deltahedral Zintl Ions of Germanium and their Functionalization with Organic Groups
Published on: February 11, 2012
Sm26.25Ge22.75O5: Oxidic Sm30Ge4O5 Superclusters Embedded in a Zintl Polyanionic Framework
Joju Sabu Mathew1, Vitaliy Romaka1, Ulrich Burkhardt2
1Faculty of Chemistry and Food Chemistry, TUD Dresden University of Technology, 01062 Dresden, Germany.
Abstract:
The heteroanionic rare-earth germanide oxide Sm26.25Ge22.75O5 was obtained by arc melting. The crystal structure determined by single-crystal X-ray diffraction (space group P4/nmm, a = 14.9838(2), c = 10.5353(1) Å) features [Sm6O] octahedra and capped [Sm8Ge] prisms that are condensed to Sm30Ge4O5 superclusters. These clusters form an interpenetrating framework with polyanionic Ge chains. Chemical bonding analysis reveals the substantial role of oxygen in stabilizing the structure: in the hypothetical oxygen-free compound, significant electron localization appears at the centers of Sm6 octahedra, coinciding with the experimentally observed oxygen positions. Consistently, DFT calculations show that the incorporation of oxygen lowers the enthalpy of formation in comparison to the hypothetical intermetallic compound. Electronic structure calculations indicate metallic conductivity for both the suboxide and the hypothetical oxygen-free intermetallic compound.
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