Gd7I12Zn: A Group 12 Atom in the Octahedral Gd6 Cluster

The title compound was synthesized from Gd, GdI3 and Zn under Ar atmosphere at 850 °C. It crystallizes in the space group R3̅ (No. 148) with lattice constants a = 15.686(1) Å and c = 10.4882(8) Å. The structure features isolated Zn-centered Gd6 octahedra with all edges and corners capped by I atoms. The disorder of the Gd atoms is rationalized via electron microscopic techniques. A computational analysis using the extended Hückel method has been carried out in order to understand the bonding of this compound. The structure of isotypic La7I12Co is also remarked (a = 16.040(1) Å and c = 10.905(2) Å).