Hydrogenated cyclic silanes

On the other hand, product studies of volatile materials for the reaction of silane 4 (no allylic hydrogen available) with thermally generated t-BuO radicals at 46 °C revealed the formation of cyclic silanes in a 46 % overall yield... 

To obtain cyclic products with functional side groups, our main interest was focused on phenylated and hydrogen containing silanes. As we were able to prove, diorganosilanes behave differently to hydrosilanes For this reason the two groups are treated separately in the following discussion. 

The H spectrum of the deuterated product shows the almost total deuteration due to the absence of peaks at s proximately 0 ppm. All of the phenyl groups have been completely removed from the silane and the hydrolysis has produced deuterated PDMS of high purity. The minute peaks observed at 7.27 and 7.37 ppm are due to residual solvents (CHCI3 and CgH respectively). The large peak at 5.31 ppm is due to the dichloromethane used as a reference for calculating the percentage deuteration in comparison with a similar spectrum recorded with the hydrogenated cyclic tetramer (D4). 

The cyclic voltammetric investigations of MeHSiCb and PhHSiCb showed, in accordance to the results of non-hydrogenated silanes, a higher reduction potential for the methylated derivative than for the phenylated one [3], In both cases the reduction is quasi-reversible, hence, with increasing potential sweep, the reduction waves shift to more negative values. 

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