KINETICS OF SILYLENE INSERTION INTO N-H BONDS AND THE MECHANISM AND KINETICS OF THE PYROLYSIS OF DIMETHYLSILYLAMINE

Product and kinetic data on the copyrolysis of silane with ammonia and of silane with dimethylamine are reported. The main products of the S iH4/NH3 reaction are disilane and silylamine, and the main products of the SiH4/Me2NH reaction are Si2H6 and Me2NSiH3. The silylamine produc ts are produced by SiH2 insertions into the N-H bonds of the amine rea ctants, and rate constants for this insertion lie in the k(2) similar to 2 x 10(9) M-1 s(-1) range, with no temperature dependence within th e errors. Kinetic and product data on the pyrolysis of dimethysilylami ne are also presented. Reactant loss followed reasonable first-order k inetics and produced rate constants consistent with Arrhenius paramete rs of log A(sec(-1)) = 12.64 +/- 0.98 and E = 48.02 +/- 3.1 kcal/mol. A mechanism of reaction, based on the kinds of silylene intermediate r eactions expected, is presented. Comparisons of mechanistic expectatio ns with the product data, however, indicate a more complex reaction sy stem.