(Ca/Sr)AuxCd1−x: Stacking variants of the CrB–FeB series

Two Homologous Intermetallic Phases in the Na–Au–Zn System with Sodium Bound in Unusual Paired Sites within 1D Tunnels

“…in place of Tr. , Thus, the Na–Au–Cd system yielded a novel condensed cluster network Na 6 Cd 16 Au 7 , (isotypic with Mg 6 Cu 16 Si 7 , despite the chemical contrasts) that contain segregated tetrahedral stars of Cd networked with individual Au atoms . Switches of the alkali-metal components to the alkaline-earth (or to rare-earth) metals with the higher field ions always produce substantial differences, particularly better ordered and more regular structures. − Certain less tightly bound alkali-metal systems also allow the formation of what may be described as zeolitic phases, or at least tunnel structures that resemble these, even though the characteristic ion exchange properties have not yet been established. Relative cation and network sizes and proportions appear critical for zeolitic structure formation.…”

The new complex lanthanum tetrelide La55Sn36.6Ge24.4

“…3 bottom left) at the same Wyckoff position also show this ten-fold coordination by La atoms with comparable distances of d La-Sn = 339.6-415.2 pm. As detailed in (7) 294.0(3) -La (8) 301.3(3) -La (14) 314.5(2) 2× -La (10) 327.9(2) 2× 1 + 6 the description of the structure refinement in the experimental section, the position Sn (11) is only partially occupied (61%) and the difference Fourier map reveals extra electron density, which is reconciled by disordered Ge 2 dumbbells formed by Ge (12) and Ge(13) atoms ( Fig. 3 bottom left).…”

“…The angular four-membered chain pieces in RE 5 Four-membered rings ([M 4 ] 8− ) in planar conformation appear in the structures of La 11 Sn 10 and the isotypic late lanthanoid germanides of the Ho 11 Ge 10 type. They are also present in the structures of ˇ-LaSn und La 2 Sn 3 (in addition to chains with terminal three-membered rings, Sn 8 14− [26]). The Sn-Sn distances alternate in the range between 296 (in La 11 Sn 10 ) and 316 pm (in ˇ-LaSn) and thus the bond lengths in the [Sn(4X) 4 ] ring of the title compound (e, f and g: 291.0-297.6 pm) are in the common range.…”

“…Both border phases, LaGe and LaSn, are dimorphic exhibiting the simple FeB (LaGe [1][2][3][4]) and CrB (LaSn [5]) structure types at higher temperatures. Despite their simple crystal structures, which exhibit planar all-trans zig-zag chains in different orientations to each other, the chemical bonding in these compounds is still puzzling and has therefore been the topic of several recent experimental and theoretical studies [4,[6][7][8][9]. The low-temperature (l.t.)…”

Cadmium-Auride AIICdxAu2– x (AII = Ca, Sr) Synthese, Kristallstruktur, chemische Bindung/ Cadmium-Aurides AIICdxAu2−x (AII = Ca, Sr) – Synthesis, Crystal Structure, Chemical Bonding

“…Proben auf den Schnitten (Ca/Sr)Cd 2 -(Ca/Sr)Au 2 [1,5,6], der eine geordnete Variante des KHg 2 -Typs darstellt [7]. Mit den M-Partnern Gold und Cadmium wurden zwei Elemente mit sehr unterschiedlicher Elektronegativität (Cd: 1.7; Au: 2.4, Werte nach Pauling [8]) und unterschiedlichem metallischen Radius (Cd: 156.8 pm; Au: 144.2 pm; [9]) gewählt, für die kürzlich auch die 1 : 1-Verbindungen AM mit Ca und Sr untersucht wurden [10,11]. Ausgangspunkt für die systematische Untersuchung der Verbindungsbildung auf den Schnitten ACd 2 -AAu 2 (A = Ca, Sr) war dabei die Tatsache, dass sowohl die Diauride CaAu 2 bzw.…”