Tris(trichlorosilyl)tetrelide Anions and a Comparative Study of Their Donor Qualities.

Trichlorosilylated tetrelides [(Cl3 Si)3 E]- have been prepared by adding 1 equiv of a soluble Cl- salt to (Cl3 Si)4 Si (E=Si) or 4 Si2 Cl6 /GeCl4 (E=Ge). To assess their donor qualities, the anions [(Cl3 Si)3 E]- (E=C, Si, Ge) have been treated with BCl3 , AlCl3 , and GaCl3 . Both BCl3 and GaCl3 give 1:1 adducts with the anionic centers. AlCl3 leads to Cl- abstraction from [(Cl3 Si)3 E]- with formation of (Cl3 Si)4 E (E=Si or Ge). (Cl3 Si)4 Ge is cleanly converted to the perhydrogenated (H3 Si)4 Ge by use of Li[AlH4 ]. Another case of Cl- abstraction was observed for [(Cl3 Si)3 Ge⋅GaCl3 ]- , which reacts with GaCl3 to afford the neutral dimer [(Cl3 Si)3 Ge-GaCl2 ]2 .