EXPERIMENTAL AND THEORETICAL-STUDIES OF THE REACTION OF ATOMIC OXYGENWITH SILANE

The flash-photolysis resonance-fluorescence technique has been employe d to measure the rate constant for O+SiH4-Products from 295-565 K, and yielded k1 = 1.23 X 10(-10) exp(-14.6 kJ mol-1/RT) cm3 s-1 with an ac curacy of about +/- 15%. The transition state for direct H-atom abstra ction has been characterized at up to the Gaussian-2 ab initio level o f 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 in sertion channels, but there is no theoretical evidence for bound tripl et intermediates in the potential energy surface. A transition state t heory analysis suggests that k1 at 1000 K is 16 times larger than prev iously thought.