Relationships between soluble Zintl anions, ligand-stabilized cage compounds, and intermetalloid clusters of tetrel (Si-Pb) and pentel (P-Bi) elements

The high abundance of nine- and seven- or eleven-atom clusters of group 14 and group 15 elements, respectively, led to an enhanced investigation of the versatile chemical reactivity of these species. The studies showed that these clusters are ideal precursors for the synthesis of larger units, functionalized cage molecules, and endohedrally filled clusters. They can further serve as building blocks for large homoatomic and heteroatomic intermetalloid clusters as well as for nanostructured materials. In this chapter, the chemistry and the structures of Zintl ions and their derivatives and of cage molecules are summarized and put in the context of intermetalloid clusters. The emphasis is put on the fact that irrespective of the starting material (Zintl ions or small low-valent organometallic compounds), the same types of intermetalloid clusters are formed, and the similarities of ligandcarrying metalloid clusters and intermetalloid anions that arise from reactions of soluble Zintl ions will be pointed out.