Molecular Zintl cluster anion

Negatively charged clusters of some of the p-metals and semimetals are also stable in solutions and can be crystallized from them as ionic molecular compounds. Known, at present, are a number of such ligand-free anionic clusters, called Zintl ions. Some examples are the clusters with general formulas PUy", Eg , Eg , aud Ej where Pn = P, As, Sb and E = Si, Ge, Sn, Pb. This chapter will limit its attention to the synthesis, structure, and functionalization of molecular anionic clusters of tin. Although both nine- and five-atom clusters are known (Figure 2.6.1), the focus will be predominantly on the nine-atom deltahedral clusters Sug and Sn which are the most readily prepared and most extensively studied species. 

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