Tetrylene-Functionalized Si 7 -Siliconoids.

The core expansion of metallic or metalloid clusters by the addition of further homo- or heteronuclear vertices is pivotal to the nucleation and growth of particles. The exohedral grafting of a low-valent functionality followed by endohedral incorporation have been identified as key steps. Following previous work on the Si 6 series, we now report the synthesis and full characterization of the amidinatotetrylene-functionalized seven-vertex siliconoids Si 7 R 5 [E(N t Bu) 2 CPh] (E = Si, Ge, Sn). In the case of the silylene derivative, the solid-state structure was determined by single crystal X-ray diffraction.