Silicon compounds with strong intramolecular steric interactions, Part 72.Oxygen and water additions to a tetrasilabuta-1,3-diene

The reaction of hexakis(2,4,6-triisopropylphenyl)tetrasilabuta-1,3-diene R2 Si=SiRSiR=SiR2 (1) with atmospheric oxygen furnishes the oxidation product R2Si(O)(2)SiROSiR(O)(2)SiR2 (5) by oxygen insertion into all Si-Si bonds. H owever, treatment of 1 with meta-chloroper-oxobenzoic acid provides R2Si(O) (2)SiR-SiR(O)(2)siR(2) (7) with retention of the Si-Si single bond. Reactio n of 1 with traces of water gives the oxatetrasilacyclopentane derivative 1 0 analogous to THE With excess water a tetrasilane-1,4-diol is formed. The structures of 5, 7, and 10 were determined by X-ray crystallography.