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)3groups 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 molecule9has a bicyclic silicon back-bone with a three- and four-membered cycle sharing one edge,10is monocyclic with four membered silicon-silicon-ring,11is polycyclic and can be derived from a Si8-cube and12is 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.