Addition of a Thallium Vertex to Empty and Centered Nine-Atom Deltahedral Zintl Ions of Germanium and Tin

Nickel atoms were inserted into nine-atom deltahedral Zintl ions of E94− (E = Ge, Sn) via reactions with Ni(cod)2 (cod = cyclooctadiene), and [Ni@Sn9]3− was structurally characterized. Both the empty and the Ni-centered clusters react with TlCp (Cp = cyclopentadienyl anion) and add a thallium vertex to form the deltahedral ten-atom closo-species [E9Tl]3− and [Ni@E9Tl]3−, respectively. The structures of [Ge9Tl]3− and [Ni@Sn9Tl]3− showed that, as expected, the geometry of the ten-atom clusters is that of a bicapped square antiprism where the Tl-atom occupies one of the two capping vertices. This illustrates that centering a nine-atom cluster with a nickel atom does not change its reactivity toward TlCp. All compounds were characterized by electrospray mass spectrometry.