ß-Amino- and Alkoxy-Substituted Disilanides.

Our recent study on formal halide adducts of disilenes led to the investigation of the synthesis and properties of ß-fluoro- and chlorodisilanides. The reaction of the functionalized neopentasilanes (Me3Si)3SiSiPh2NEt2 and (Me3Si)3SiSiMe2OMe with KOtBu in the presence of 18-crown-6 provided access to structurally related ß-alkoxy- and amino-substituted disilanides. The obtained Et2NPh2Si(Me3Si)2SiK·18-crown-6 was converted to a magnesium silanide and further on to Et2NPh2Si(Me3Si)2Si-substituted ziroconocene and hafnocene chlorides. In addition, an example of a silanide containing both Et2NPh2Si and FPh2Si groups was prepared with moderate selectivity. Also, the analogous germanide Et2NPh2Si(Me3Si)2GeK·18-crown-6 could be obtained.

Disilene Fluoride Adducts versus ß-Halooligosilanides.

Extending the chemistry of disilene fluoride adducts studied earlier by us, we investigated the formation of 1,1-bis(trimethylsilyl)fluorodiphenylsilylsilanide, which was prepared by reaction of (Me3Si)3SiSiPh2F with KOtBu. The formed FPh2SiSi(Me3Si)2K displays distinctively different structural and spectroscopic features compared to the earlier reported F(Me3Si)2SiSi(SiMe3)2K. While the latter eliminates metal fluoride upon reaction with MgBr2, the respective magnesium silanide is formed from FPh2SiSi(Me3Si)2K. Reaction of (Me3Si)3SiSiPh2Cl with KOtBu proceeded similarly, but the formed ClPh2SiSi(Me3Si)2K easily undergoes potassium chloride elimination to the disilene Ph2Si═Si(SiMe3)2. Compared to F(Me3Si)2SiSi(SiMe3)2K, which can be regarded as a disilene fluoride adduct, structural, spectroscopic, and reactivity properties of FPh2SiSi(Me3Si)2K distinguish it as a ß-fluorodisilanide.

Synthesis and structural diversity of oligosilanylzinc compounds.

Reactions of potassium oligosilanyls with ZnCl(2) lead to the formation of oligosilanylzinc compounds with zinc's coordination sphere expanded by ligation of TMEDA, an additional oligosilanyl group, or a chloride ion.