Aufbau von Erdalkalimetall‐Arsen‐Käfigstrukturen durch die Metallierung von Triisopropylsilylarsan mit Calcium‐, Strontiumund Barium‐bis[bis(trimethylsilyl)amid] in Tetrahydrofuran

Formation of Alkaline Earth Metal‐Arsenic Cages via the Metalation of Triisopropylsilylarsane with Calcium, Strontium, and Barium Bis[bis(trimethylsilyl)amide] in Tetrahydrofuran The metalation of triisopropylsilylarsane with the alkaline earth metal bis[bis(trimethylsilyl)amides] in tetrahydrofuran yields the THF complexes of calcium ( 1 ), strontium ( 2 ), and barium‐bis(triisopropylsilylarsanide) ( 3 ). Dissolving of these compounds in toluene leads to the elimination of triisopropylsilylarsane and the formation of the THF complexes of tetraalkaline earth metal hexakis(triisopropylsilylarsanide)‐triisopropylsilylarsanediide of calcium ( 4 ), strontium ( 5 ), and barium ( 6 ), respectively. The central polyhedron of compound 4 can be described as two trigonal bipyramids with the metal atoms in apical positions, connected via the arsanediide substituent as a common corner. The central moieties of the compounds 5 and 6 consist of four trigonal bipyramids which are connected by common edges as well as common faces.     

Ab‐initio‐Berechnung des Tetracarbonatoscandat‐Ions in Na5[Sc(CO3)4] · 2 H2O. Einkristallstrukturbestimmung,Schwingungsspektren und thermischer Abbau

Ab Initio Calculation of the Tetracarbonatoscandate‐Ion in Na₅[Sc(CO₃)₄] · 2 H₂O. Single Crystal Structure Determination, Vibrational Spectra, and Thermal Decomposition Normal modes of the tetracarbonatoscandate‐ion, [Sc(CO₃)₄]^5–, were determined by ab initio calculations and were compared with experimental data of Infrared‐ and Raman‐spectra of the compound Na₅[Sc(CO₃)₄] · 2 H₂O. A necessary redetermination of the structure with single crystal x‐ray diffraction data (tetragonal, P42₁c (Nr. 114), Z = 2, a = 746,37(4) pm, c = 1157,0(2) pm, V_EZ = 644,5(1) 10⁶ pm³) allows the discussion of existing hydrogen bonds. Determination of the thermal behaviour indicates a two‐stage decomposition reaction, but no corresponding intermediate could be isolated.