REACTIONS OF DECAMETHYLCYCLOPENTASILANE WITH HALIDES (LEWIS-ACIDS)

Decamethylcyclopentasilane diluted in CCl4 was treated with several chlorides in order to obtain the monohalogenated derivative. SbCl5 and FeCl3 proved to be most efficient due to a minimum occurrence of terminally chlorinated silane chains deriving from ring cleavage and polychlorinated products. The system SbCl5/CCl4 was studied extensively and a proposal of a possible reaction pathway is given due to inertness of the solvent, Lewis acidity of the salts, inductive as well as electronic and steric factors. Similarly, with AlBr3, a bromination took place and monobromononamethylcyclopentasilane was formed. By reaction with PCl5 only 1,5-dichlorodecamethylpentasilane was obtained in high yield, no other ring cleavage products were found.