Trimethylsilyl radicals disproportionation

The generation of di- and trimethylsilyl radicals by the reactions of hydrogen atoms with di- and trimethylsilane and their subsequent reactions have been described23. Three main products were observed in these reactions 1,1,2,2-tetramethyldisilane, pentamethyldisilane and hexamethyldisilane which are formed by both radical coupling and disproportionation processes. The authors describe a detailed kinetic analysis of the various reactions of interest but have difficulty in providing a mechanistic description that fully fits their observed data23. 

When pentamethyldisilanyl radicals were produced by hydrogen atom abstraction in a room-temperature solution, they also underwent disproportionation and recombination reactions238. No evidence was found for fragmentation to dimethylsilylene and a trimethylsilyl radical. 

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