Apparent 1,4 Addition to Dienes

As previously mentioned, the reactions between Si and SiX4 may or may not involve free Si atoms in the gas phase. The equilibrium shown in equation (11) has been observed for a variety of silicon halides at temperatures above 800°C. Since the forward reaction represents an increase in entropy, it proceeds most readily under high-temperature and low-pressure conditions. For example, for the reaction of Si with Sip4 to give SiFj, the percent conversion increases from about 50% at 1150°C to about 90% at 1400°C.  

Other reactions of silicon with halogen-containing compounds are listed below  

This same process was also believed to be responsible for the better yields of dialkyldichlorosilanes and alkyltrichlorosilanes in the synthesis of these compounds when Cu is added to the system.  

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