Reactions of Methylsilanes by Gas Discharge

From corresponding reactions with SiH-containing methylsilanes, the main products synthesized were disilanes [36] MeH2Si—SiH2Me from Me2SiH2, and 

Compared to those just described, our investigations utilizing high frequency gas discharge [30] had the advantage that no contact is made between reactant and electrodes, and that reactions induced by this kind of energy transfer proceed at temperatures below 200 °C, whereas temperatures of the order of 600-700 °C are required for pyrolysis [31]. In order to sustain this plasma state, the pressure in the system was not permitted to exceed 10 mm Hg, while our pyrolysis reactions were carried out just below atmospheric pressure. 

The compounds produced from SiMe as a result of gas discharge are shown in Table 12. In a first run, the storage flask was cooled to —70 °C during the whole reaction. In a second run, the storage flask was allowed to warm gradually to 20 °C. By this means, further liquid compounds were obtained, due to the more volatile products participating in subsequent reactions. These additional compounds obtained are also shown in Table 12. 

Performing this reaction with MeSiH3 under similar conditions, a pale yellow powder of composition Si C H = 1.0 1.1 2.1 was produced. The IR spectrum (KBr pressed disc) showed that CH, SiH, SiCH3 and SiCH2Si groups were present in this substance. The small amount of liquid reaction product consisted essentially of MeH2Si-SiH2Me. 

MeaSi - CH2 - CH2 - SiHMe2 MeaSi - CH2 - CH2 - SiMea (C2H5)Me2Si - CH2 - SiMea (Me,H Si-CH,),SiMe, 

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