The pyrolysis of organometallic compounds IV. Kinetic studies of the decomposition of tetramethylsilane

The pyrolysis of tetramethylsilane has been investigated in a flow system at 810-980°K and 0.1-30 mm. In reaction vessels seasoned by pyrolysis of tetramethylsilane the decomposition is independent of surface to volume ratio and the first-order rate constants may be represented by the equation: log₁₀k(sec^-1) = (14.30 ± 0.23) - (67600 ± 800)/(2.303R·T) The major products formed are methane, ethane, trimethylsilane, 1,1,3,3-tetramethyl-1,3-disilacyclobutane, hexamethyldisilane, and 2,2,4,4-tetramethyl-2,4-disilapentane. A reaction scheme is proposed which invokes the existence of a silicon-carbon p-bonded intermediate. In a reaction vessel seasoned by the pyrolysis of tetramethyltin, the decomposition of tetramethylsilane is heterogeneous, and certain products are obtained which indicate that rapid surface initiated rearrangement reactions are taking place. © 1972.