Selective One-Pot Syntheses of Mixed Silicon-Germanium Heteroadamantane Clusters

Si_x Ge_y alloys are emerging materials for modern semiconductor technology. Well-defined model systems of the bulk structures aid in understanding their intrinsic characteristics. Three such model clusters have now been realized in the form of the Si_x Ge_y heteroadamantanes [0], [1], and [2] through selective one-pot syntheses starting from Me₂ GeCl₂ , Si₂ Cl₆ , and [nBu₄ N]Cl. Compound [0] contains six GeMe₂ and four SiSiCl₃ vertices, whereas one and two of the GeMe₂ groups are replaced by SiCl₂ moieties in compounds [1] and [2], respectively. Chloride-ion-mediated rearrangement quantitatively converts [2] into [1] at room temperature and finally into [0] at 60 °C, which is not only remarkable in view of the rigidity of these cage structures but also sheds light on the assembly mechanism.