Notizen: Anorganische Polyederverbindungen, II. Zintls „Polyanionige Salze“: Darstellung der kristallinen Verbindungen [Na4 · 7 en] Sn9, [Na4 · 5 en]Ge9 und [Na3 · 4 en] Sb7. Die Kristallstruktur des [Na4 · 7 en] Sn9 / Inorganic Polyhedral Compounds, II. Inorganic Polyhedral Compoinds, II1 Zintl’s “Polyanionic Salts”: Synthesis of the Crystalline Compounds [Na4 · 7 en]Sn9, [Na4 · 5 en]Ge9 and [Na3 · 4 en]Sb7. The Crystal Structure of [Na4 · 7 en]Sn9

Upon use of a synthetic method reported earlier by us respective alloys of Na/Sn, Na/Ge and Na/Sb are dissolved in ethylenediamine and the title compounds precipitated from the solutions in high yield. By recrystallisation well shaped, stable crystals are obtained. The crystal structure of [Na4 · 7 en]Sn9 confirms the presence of a Sn9 4---polyhedron which had been suggested by us on the basis of other investigations. The Sn9 4--polyhedron may be described as a distorted tricapped trigonal prism. Ethylenediamine is coordinated to Na+-ions exclusively.