Endohedral Stannaspherenes M@Sn12−: A Rich Class of Stable Molecular Cage Clusters

Trapped in a cage: Combined experimental and theoretical evidence shows that the stannaspherene Sn122− can trap a transition-metal or f-element atom (green) to form a stable endohedral cluster (see figure). The central metal atom induces very little distortion in the icosahedral cage. The clusters can be viewed as “superatoms” for use in materials with tunable magnetic, electronic, and chemical properties.