SILICON-COMPOUNDS WITH STRONG INTRAMOLECULAR STERIC INTERACTIONS .49.DISILANES AND A DISILENE WITH ASYMMETRIC SUBSTITUTION ON THE SILICON ATOMS

Treatment of chlorobis(2,4,6-triisopropylphenyl)silane (Ar2SiHCl) with lithium naphthalenide and subsequent,addition of the chlorosilanes R2 SiHCl (R =(i)Pr, (t)Bu, Mes) gives the unsymmetrical disilanes R2HSiSi HAr2 which are smoothly converted into the 1,2-dichlorodisilanes 8-10. The X-ray structure analysis of the 1,1-dimesityldisilane 10 reveals a staggered conformation with the chlorine atoms disposed in an anti o rientation. Whilst the reductive chloride elimination from the 1,1-dia lkyldichlorodisilanes 8 and 9 did not give the corresponding disilenes , the same reaction of 10 provided bright yellow crystals of mesityl-2 ,2-bis(2,4,6-triisopropylphenyl)disilene, the structure of which was c onfirmed by a complete NMR study.