Selenium-rich octanuclear iridium clusters with mixed-valent selenium ligands in the densest known packing of ellipsoids
Publikation: Beitrag in Fachzeitschrift › Forschungsartikel › Beigetragen › Begutachtung
Beitragende
Abstract
Dark-red air-stable crystals of Ir8Se28Br 14·2H2O were obtained by reacting iridium in an excess of selenium and selenium tetrabromide at 300 °C for one week. The crystal structure is monoclinic (space group P21/n) with a = 1274.66(3) pm, b = 1211.48(3) pm, c = 1743.82(4) pm, and β = 91.227(1)° at 296(1) K. The structure consists of uncharged clusters Ir8Se 28Br14 = (Ir3+)8(Se2 2-)(Se42-)6(SeBr2) 2(Br-)10 with two water molecules attached to each of them. Selenium adopts three different oxidation states, -I in the diselenide dumbbell, -I and ±0 in the tetraselenide chains, and +II in the SeBr2 units. The iridium(III) cations are coordinated octahedrally by selenium atoms and bromide ions. The octahedra share common vertices, while the oligoselenide anions provide high intra-cluster connectivity: μ6-η2 in the case of Se 22- and μ4-η3 for Se 42-. In parts the cluster resembles a cut-out of the rhombohedral Ir3Se8 framework structure. The ellipsoidal clusters form an excellent approximation of the mathematically predicted densest known packing of ellipsoids, featuring the coordination number of 14.
Details
Originalsprache | Englisch |
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Seiten (von - bis) | 719-723 |
Seitenumfang | 5 |
Fachzeitschrift | Zeitschrift fur Anorganische und Allgemeine Chemie |
Jahrgang | 640 |
Ausgabenummer | 5 |
Publikationsstatus | Veröffentlicht - Apr. 2014 |
Peer-Review-Status | Ja |
Externe IDs
ORCID | /0000-0002-2391-6025/work/159171941 |
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Schlagworte
ASJC Scopus Sachgebiete
Schlagwörter
- Clusters, Densest ellipsoid packing, Iridium, Mixed-valent compounds, Selenium