Treatment of 1,3-di(t-butyldimethylsilyl)-1,3-disilabicyclo[1.1.0]butane 1a with excess lithium in THF provided 1,3-dilithio-1,3-disilabicyclo[1.1.0]butane 2 via reductive cleavage of the exocyclic Si-Si bonds at the bridgehead silicon atoms. In the single crystals obtained by recrystallization in the presence of 1,2-dimethoxyethane (DME), 2 exists as a solvent-separated ion pair, and its anionic part forms an aggregate that contains three lithium atoms sandwiched by two 1,3-disilabicyclo[1.1.0]butan-1,3-diide units. Treatment of 2 with chlorotriisopropylsilane provided triisopropylsilyl-substituted 1,3-disilabicyclo[1.1.0]butane 1b. The structural characteristics of 1b are close to that of the short-bond isomer, which is consistent with previous theoretical predictions concerning the steric effects of the bridgehead substituents on the structure of silabicyclo[1.1.0]butane.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry