The mechanism and rate constants for oxidation of indenyl radical C9H7 with molecular oxygen O2: a theoretical study
Journal Article
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· Physical Chemistry Chemical Physics. PCCP
- Samara Univ. (Russia); Lebedev Physical Inst., Samara (Russia); Florida International University
- Samara Univ. (Russia); Lebedev Physical Inst., Samara (Russia)
- Samara Univ. (Russia); Florida International Univ., Miami, FL (United States)
Ab initio G3(MP2,CC)//B3LYP/6-311G(d,p) calculations have been carried out in this work to map out the C9H7O2 potential energy surface in relation to the reaction of the 1-indenyl radical with molecular oxygen. The resulting energetics and molecular parameters of the species involved in the reaction have been then utilized in Rice–Ramsperger–Kassel–Marcus master equation calculations of temperature- and pressure-dependent reaction rate constants and product branching ratios. The results demonstrate that, while the reaction is insignificant at low temperatures, at higher temperatures, above 800 K or higher depending on the pressure, the prevailing reaction channel leads to the formation of the 1-H-inden-1-one + OH products via a 1,3-H shift from C to O in the initial association complex W1 accompanied by OH elimination through a high barrier of 25.6 kcal mol₋1. The branching ratio of 1-H-inden-1-one + OH increases from ~61% to ~80% with temperature, whereas c-C6H4-CH2CHO + CO (32–12%) and coumarin + H (7–6%) are significant minor products. The total rate constant of the indenyl + O2 reaction leading to the bimolecular products is independent of pressure and exceeds 1.0 × 10₋15 cm3 molecule₋1 s₋1 only at temperatures above 2000 K, reaching 6.7 × 10₋15 cm3 molecule₋1 s₋1 at 2500 K. The indenyl + O2 reaction is concluded to be too slow to play a substantial role in oxidation of the five-member ring in indenyl and the present results corroborate the assertion that molecular oxygen is not an efficient oxidizer of five-member-ring radicals.
- Research Organization:
- Florida International Univ., Miami, FL (United States)
- Sponsoring Organization:
- Ministry of Education and Science of the Russian Federation; Ministry of Education and Science of the Russian Federation; USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- FG02-04ER15570
- OSTI ID:
- 1594769
- Alternate ID(s):
- OSTI ID: 1507167
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP, Journal Name: Physical Chemistry Chemical Physics. PCCP Journal Issue: 17 Vol. 21; ISSN 1463-9076; ISSN PPCPFQ
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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Journal Article
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Wed Mar 01 04:00:00 UTC 1995
· Organometallics
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OSTI ID:28693