46275-AC6
Characterization of Stannaspherene and Endohedral Stannaspherenes
One of the major objectives of cluster science is to discover stable atomic clusters, which may be used as building blocks for cluster-assembled nanomaterials. The discovery and bulk synthesis of the fullerenes have sprouted new research disciplines in chemistry and nanoscience and precipitated intense interests to search for other similar stable clusters. However, despite major research efforts, no other analogous gas-phase clusters have been found and yielded to bulk syntheses. We have discovered in cluster beam experiments two highly stable and symmetric cage clusters, stannaspherene (Sn122–) and plumbaspherene (Pb122–). The names for these two clusters derive from their icosahedral (Ih) symmetry and delocalized spherical π-bonding that are characteristics of buckminsterfullerene C60. Stannaspherene and plumbaspherene have diameters comparable to that of C60 and can be considered as inorganic analogs of the buckyball. The large internal space in Sn122– has been shown to be able to trap any transition metal atom to form new endohedral cage clusters, M@Sn12–, analogous to endohedral fullerenes. The doped atom in M@Sn12– keeps its quasi-atomic nature with large magnetic moments. These endohedral cages form a rich class of new building blocks for cluster-assembled materials with tunable magnetic, electronic, and chemical properties. During our attempt to synthesize endohedral stannaspherenes, we crystallized a new Pd2@Sn184– cluster, which can be viewed as the fusion of two Pd@Sn122– clusters. This result suggests that stannaspherene, plumbaspherene, and a large number of their endohedrally doped species can be synthesized in the bulk.
