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

Trichlorosilylated tetrelides [(Cl 3 Si) 3 E] − have been prepared by adding 1 equiv of a soluble Cl − salt to (Cl 3 Si) 4 Si (E=Si) or 4 Si 2 Cl 6 /GeCl 4 (E=Ge). To assess their donor qualities, the anions [(Cl 3 Si) 3 E] − (E=C, Si, Ge) have been treated with BCl 3 , AlCl 3 , and GaCl 3 . Both BCl 3 and GaCl 3 give 1:1 adducts with the anionic centers. AlCl 3 leads to Cl − abstraction from [(Cl 3 Si) 3 E] − with formation of (Cl 3 Si) 4 E (E=Si or Ge). (Cl 3 Si) 4 Ge is cleanly converted to the perhydrogenated (H 3 Si) 4 Ge by use of Li[AlH 4 ]. Another case of Cl − abstraction was observed for [(Cl 3 Si) 3 Ge ⋅ GaCl 3 ] − , which reacts with GaCl 3 to afford the neutral dimer [(Cl 3 Si) 3 Ge−GaCl 2 ] 2 .