On the Nature of Bridging Metal Atoms in Intermetalloid Clusters: Synthesis and Structure of the Metal-Atom-Bridged Zintl Clusters [Sn(Ge9 )2 ]4- and [Zn(Ge9 )2 )]6.

On the Nature of Bridging Metal Atoms in Intermetalloid Clusters: Synthesis and Structure of the Metal-Atom-Bridged Zintl Clusters [Sn(Ge9 )2 ]4- and [Zn(Ge9 )2 )]6.