Hexa­bromo- and hexa­iodo­disilane: small and simple mol­ecules showing completely different crystal structures

Si₂Br₆ and Si₂I₆ were prepared through de­phenyl­ation of hexa­phenyl­disilane with acetyl bromide or acetyl iodide in the presence of the corresponding aluminium halide. It is inter­esting to note that Si₂Br₆ and Si₂I₆ do not form isomorphous structures. Moreover, an ortho­rhom­bic polymorph of the present structure of Si₂I₆ is already known. Although the title compounds feature such small and simple mol­ecules they show completely different crystal structures.