Kinetics and mechanism of the shock induced thermal decomposition of n-propylsilane

✍ Scribed by B. A. Sawrey; H. E. O'Neal; M. A. Ring; D. Coffey Jr.

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 727 KB
• Volume: 16
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550160703

✦ Synopsis

The kinetics and mechanism of the thermal decomposition of n-propylsilane have been studied by the single pulse shock tube-comparative rate technique a t pressures around 4700 torr between 1095-1240 K. The primary dissociation processes are 1,l and 1,2 H, elimination with &,,, = 0.75 and &,,* = 0.25, respectively. Subsequent decompositions of the primary process product, n-propylsilylene, to propylene and ethylene is complete even in the presence of excess butadiene. Possible mechanistic paths for these decompositions are discussed and an activation energy range of 30 f 4 kcal is established for both processes. Induced decomposition via silylene chains accounts for 36-46% of the overall reaction in the uninhibited decomposition of n-propylsilane. The silylene chains are quenched in excess butadiene, and studies under maximum inhibition give overall decomposition kinetics of, log k(nPrSiD,, s -' ) = 15.26-65,300 -c 1950 ca1/2.303. Computer modeling results of the overall reaction both in the absence and presence of butadiene are also presented and shown to be in acceptable agreement with the experimental observations.