Hydrogen Atom Attack on Propene
Claudette M. Rosado-Reyes, Jeffrey A. Manion, and Wing Tsang
Chemical and Biochemical Reference Data Division(832),
NIST Gaithersburg, MD 20899.
The reaction of propene(CH3CH=CH2) with hydrogen atoms has been investigated in a heated single-pulsed shock tube at temperature of 925-1078K and pressures of 2-3 bar. Stable products from various reaction channels (H atom addition and by inference H abstraction) have been identified and quantified by gas chromatography and mass spectrometry. The reaction for the H addition channel involving methyl displacement from propene has been determined relative to the methyl displacement from 1,3,5-trimethylbenzene (1,3,5-TMB), with k (1,3,5-TMB + H → m-Xylene + CH3) = 6.7 ´ 1013 exp(-3255/T) cm3/mole·sec,
k (Propene + H → H2C=CH2 + CH3) = 3.0 ´ 1013 exp(-1709/T) cm3/mole·sec; (925-1078K)
The reaction of Propene + H has also been studied relative to the previously studied reaction of Propyne + H,
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The results showed that the rate constant for the displacement reaction with propyne is a factor of 1.2 ± 0.1 larger than that for propene.
The present is compared with relevant previous results on aromatics and olefins.