Arsenidostannate mit Arsen-analogen [SnAs]-Schichten: Darstellung und Struktur von Na[Sn2As2], Na0,3Ca0,7[Sn2As2], Na0,6Sr0,6[Sn2As2], Na0,6Ba0,4[Sn2As2] und K0,3Sr0,7[Sn2As2]

Arsenidostannates with SnAs] Nets Isostructural to Grey Arsenic: Synthesis and Crystal Structure of NaSn₂As₂], Na_0.3Ca_0.7Sn₂As₂], Na_0.4Sr_0.6Sn₂As₂], Na_0.6Ba_0.4Sn₂As₂], and K_0.3Sr_0.7Sn₂As₂] The metallic lustrous compounds NaSn₂As₂], Na_0.3Ca_0.7Sn₂As₂], Na_0.4Sr_0.6Sn₂As₂], Na_0.6Ba_0.4Sn₂As₂] and K_0.3Sr_0.7Sn₂As₂] were prepared from melts of mixtures of the elements. The compounds crystallize in the trigonal system (space group R3 m, No. 166, Z = 3) with lattice constants see in “Inhaltsübersicht”. The structures are isotypic to SrSn₂As₂] containing puckered SnAs] nets which are stacked with a sequence of six layers. The E(I)/E(II) atoms are located between each second SnAs] layer in trigonal antiprismatic interstices formed by As atoms. In the resulting Sn₂As₂] double layers the _∞²SnAs] nets are stacked in such a way that additional Sn—Sn contacts arise.