A Second Metalloid Ga18 Cluster and Its Topological Similarity to the High‐Pressure Ga‐II Modification

The topology of many modifications of elemental gallium is reflected in the large variety of metalloid Ga clusters that have been isolated as intermediates on the way from the metastable molecular GaX species (X=Cl, Br, I) by means of disproportionation to the bulk metal. Herein, we report the synthesis and characterization of the first metalloid cluster anion [Ga18(PtBu2)10]3− with the singular core topology that resembles the gallium high-pressure modification Ga-II. The stabilization of the cluster anion through ion-pair contacts with a chainlike “Li4Br2 backbone” is discussed. Furthermore, the compound is discussed in context of the other metalloid clusters Ga18R8 and Ga22R8 (R=SitBu3) and their structural relation to the elemental modifications Ga-III and β-Ga, respectively.