Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6679398 | Proceedings of the Combustion Institute | 2009 | 10 Pages |
Abstract
This work reports measurements of the absolute rate coefficients and Rice-Ramsperger-Kassel-Markus (RRKM) master equation (ME) simulations of the C2H3 + C3H6 reaction. Direct kinetic studies were performed over a temperature range of 300-700 K and pressures of 15, 25, and 100 Torr. Vinyl radicals were generated by laser photolysis of vinyl iodide at 266 nm, and time-resolved absorption spectroscopy was used to probe vinyl radicals through absorption at 423.2 nm. A weighted modified Arrhenius fit to the experimental rate constant is k1 = (1.3 ± 0.2) Ã 10â12 cm3 moleculeâ1 sâ1(T/1000)1.6 exp[â(1510 ± 80/T)]. Fifteen stationary points and 48 transition states on the C5H9 potential energy surface (PES) were calculated using the G3 method in Gaussian 03. RRKM/ME simulations were performed using VariFlex on a simplified PES to predict pressure dependent rate coefficients and branching fractions for the major channels. For temperatures between 350 and 700 K, the calculated rate coefficient agrees with the experimental rate coefficient within 20%. At low temperatures, the primary products are the initial adducts 4-penten-2-yl and 2-methyl-3-buten-1-yl. At higher temperatures, the dominant products are 1,3-butadiene + methyl, allyl + ethene, and 1,3-pentadiene + H. Although C2H3 + C3H6 â allyl + ethene is thermodynamically favored, the simulations predict that it does not become the dominant product until 1700 K.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
C. Franklin Goldsmith, Huzeifa Ismail, Paul R. Abel, William H. Green,