When Si8R*6 (R* = Si(tBu)3) is reacted with mild halogenation reagents like carbon tetrachloride, carbon tetrabromide, tin tetrachloride and iodine, new compounds are formed which besides the Si(tBu)3 groups have halide ligands and a silicon-silicon backbone which is either cyclic, bicyclic or polycyclic. We here report on the molecular and crystal structures of four derivatives: Si5R*3Cl5 (9), Si4R*3Br5 (10), Si8R*4Cl6 (11) and Si8R*3I11 (12). The molecule 9 has a bicyclic silicon back-bone with a three- and four-membered cycle sharing one edge, 10 is monocyclic with four membered silicon-silicon-ring, 11 is polycyclic and can be derived from a Si8-cube and 12 is bicyclic with a four- and five-membered silicon ring sharing one edge. We also propose some possible reaction mechanisms which follow from observations found during our experiments.
Zeitschrift Für Anorganische Und Allgemeine Chemie , 2007, 633 (13-14), 2425-2430.