Experimental and theoretical studies of the reaction of atomic oxygen with silane

The flash-photolysis resonance-fluorescence technique has been employed to measure the rate constant for O+SiH4→products from 295–565 K, and yielded k1=1.23×10−10 exp(−14.6 kJ mol−1/RT) cm3 s−1 with an accuracy of about ±15%. The transition state for direct H-atom abstraction has been characterized at up to the Gaussian-2 ab initio level of theory. With small adjustments it is possible to model kinetic data for O+SiH4 in terms of an abstraction channel leading to OH+SiH3. This agreement does not rule out minor participation by addition or insertion channels, but there is no theoretical evidence for bound triplet intermediates in the potential energy surface. A transition state theory analysis suggests that k1 at 1000 K is 16 times larger than previously thought.