For the kinetic treatment of the rearrangement reactions of siloxanes it was necessary to study the relative bond dissociation energies of the various silicon-oxygen bonds present in the siloxane chain. Therefore, appearance potentials of the trimethyl-silyl-and trimethyl-siloxy-ions formed in the course of fragmentation were determined by means of the electron impact method, and bond dissociation energies of the corresponding bonds were evaluated. A 20% increase in the bond dissociation energy was found for the silicon-oxygen bond adjacent to the vinyl-group in vinyl-substituted siloxanes. On the basis of this finding a differential equation was established which correctly describes the rearrangement reaction of heptamethyl-3-vinyl-trisiloxane.
|Number of pages||8|
|Journal||International Journal of Mass Spectrometry and Ion Physics|
|Publication status||Published - Jul 1971|