I(8)Sb(10)Ge(36)

Abstract

Single crystals of the title compound, octa-iodide deca-anti-monate hexa-tria-conta-germanide, were grown by chemical transport reactions. The structure is isotypic with the analogous clathrates-I. In this structure, the (Ge,Sb)(46) framework consists of statistically occupied Ge and Sb sites that atoms form bonds in a distorted tetra-hedral arrangement. They form polyhedra that are covalently bonded to each other by shared faces. There are two polyhedra of different sizes, viz. a (Ge,Sb)(20) dodeca-hedron and a (Ge,Sb)(24) tetra-cosa-hedron in a 1:3 ratio. The guest atom (iodine) resides inside these polyhedra with symmetry m3 (Wyckoff position 2a) and 2m (Wyckoff position 2d), respectively.

Fig. 1.

Structure du clathrate I8Sb10Ge36 montrant les deux types de polyèdres: les dodécaèdres pentagonaux (Ge, Sb)20 (en rose) et les tétrakaïdècaèdres (Ge, Sb)24 (en gris). Les atomes d'iode sont localisés au centre de ces polyèdres.

Fig. 2.

Deux cages adjacentes dans la structure du clathrate I8Sb10Ge36 avec un déplacement des ellipsoïdes à 95% de probabilité.