Interpenetrating As 20 Fullerene and Ni 12 Icosahedra in the Onion-Skin As@Ni 12 @As 20 3 Ion

The As@Ni12@As203- ion was prepared from As7(3-) and Ni(COD)2 in ethylenediamine solutions and isolated as the Bu4P+ salt (As, arsenic; Ni, nickel; COD, cyclooctadiene; Bu, butyl; P, phosphorus). The anion contains an icosahedral Ni12(mu12-As)3- fragment that resides at the center of an As20 dodecahedral (fullerene) cage to give an onion-skin-like As@Ni12@As203- cluster with Ih point symmetry. The icosahedron and pentagonal dodecahedron are reciprocal platonic solids, and the 32 surface atoms form a dimpled geodesic sphere composed of 60 triangular faces. In the gas phase, the As@Ni12@As203- ion sequentially loses all 21 As atoms to form a series of Ni12As(21-x) clusters where 0 </= x </= 21, inclusively.