Reduzierte Oxoniobate mit Metallclustern

An X-Ray Powder and Electron Diffraction Study of Reduced Tantalates with the Perovskite Structure, Na1−xSrxTaO3, 0<x≤0.4

“…Only a few perovskiterelated compounds are reported to be superconducting in these systems, e.g., Li-intercalated KCa Nb O (4). In more reduced oxoniobates with an electron con"guration close to d, niobium}niobium bonded units are frequently found, such as the Nb O clusters (5). Tantalum is even more averse than niobium to adopt an oxidation state lower than maximal, and very few reduced complex tantalum oxides are reported in the literature.…”

Niobium Alcoholate Clusters with an Octahedral Arrangement of Metal Atoms: [K(CH3OH)4]2 [Nb6(OCH3)18] and [Na([18]crown‐6)(C2H5OH)2]2 [Nb6(OC2H5)12(NCS)6]

“…Yet, similar compounds with isolated cluster units for X i = O and F are missing, not only for M = Nb but for all the metals in the 4th and 5th Groups of the periodic table. Although oxido niobates with [Nb 6 O i 12 ] units, which are three-dimensionally connected through intercluster-bridging oxido ligands, are thoroughly investigated, in particular by Simon et al, [12] cluster compounds with isolated [M 6 O i 12 ] cluster units linked to their neighbors merely by weak interactions are unknown. [13] We report herein the first two representatives of a new class of compounds, [13] reduced niobium alcoholates of the [M 6 X 12 ] type: [K(CH 3 OH) 4 ] 2 [Nb 6 (OCH 3 ) 18 ] (1) and [Na([18]crown-6)(C 2 H 5 OH) 2 ] 2 [Nb 6 (OC 2 H 5 ) 12 (NCS) 6 ](2).…”

[PtIn6]10+ Octahedra in PtIn7F13: The First Compound of a New Class of Metal-Cluster Fluorides

“…Such a [PtIn 6 F 24 ] cluster is unique as no fluorides are known which contain comparable units. Analogous to the highly ionic transition metal compounds containing M 6 X i 12 X a 6 clusters (i inner (German: innere), a outer (äuûere)) [11] with only 18 surrounding anions and significantly shorter M ± M distances (for example, low valent oxoniobates [12,13] or oxomolybdates [14] ) the F(2) atoms can be denoted as inner F ligands (F i ). [10] The In(2) atoms are terminally coordinated by four F atoms, whereas the In(3) atoms have three nearest terminal F atoms and, in addition, two further F(2) atoms coordinate and these lie above the In(3) ± In(3) edges.…”