- Author
-
McGivern, W. S.
|
Manion, J. A.
|
Tsang, W.
- Title
- Kinetics of the Thermal Decomposition of t-Butyl-1,3-Cyclopentadiene: Ring Expansion and Radical Formation.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Chemical and Physical Processes in Combustion. Technical Meeting, 2005. Proceedings. Combustion Institute/Eastern States Section. November 13-15, 2005,
Orlando, FL,
10-13 p.,
2005
- Keywords
-
combustion
|
chemical kinetics
|
thermal decomposition
|
experiments
|
soot
|
radicals
|
polycyclic aromatic hydrocarbons
- Identifiers
- Arrhenius parameters; best-fit Arrhenius parameters
- Abstract
- The formation of soot in combustion processes1 is typically initiated by the formation of aromatic ring species, followed by the addition of small unsaturated radicals to form polycyclic aromatic hydrocarbons (PAH). Subsequent expansion of these PAH systems results in nucleation sites for the formation of particulate soot. A significant pathway for the formation of aromatic species in pyrolytic environments is via recombination of propargyl (C3H3) radicals to form benzene molecules. Recent theoretical studies by Miller and Klippenstein have detailed reactions through several mechanistic pathways to the formation of benzene. Important among these is the rearrangement of fulvene to benzene via a carbene intermediate. Additional pathways for the rearrangement of fulvene to benzene in the presence of H atoms were calculated by Melius, et al with energetics determined using bond-additivity corrected MP4 (BAC-MP4) methods. In the present study, we examine the thermal decomposition of t-butyl cyclopentadiene (TBCP). TBCP exists in three isomers, which rapidly interconvert via 1,5 sigmatropic shifts of the H atom around the cyclopentadienyl ring. The naming of the isomers in the present study will be defined in terms of the location of the t-butyl moiety on the cyclopentadienyl ring (e.g. 5-t-butyl-(1,3-cyclopentadiene) will be abbreviated 5-TBCP). The thermal decomposition of the TBCP isomer mixture resulted in the formation of t-butyl radicals, cyclopentadienyl radicals, isobutene, cyclopentadiene, and toluene. The origins of each of these products will be discussed, and, where possible, rate expressions will be provided for the relevant reactions.