Formation of D atoms in the pyrolysis of toluene-d/sub 8/ behind shock waves: kinetics of the reaction C/sub 7/D/sub 8/ + H. -->. C/sub 7/D/sub 7/H + D

Journal Article · Thu Sep 13 04:00:00 EDT 1984 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150663a035· OSTI ID:6155388

Rao, V S; Skinner, G B

Dilute mixtures (5-20 ppm) of toluene-d/sub 8/ in argon were pyrolyzed behind reflected shock waves at temperatures of 1410-1730 K and total pressures of 3 atm. In a second group of experiments, mixtures of 20 ppm toluene-d/sub 8/ and 5 ppm neopentane (which acted as a source of H atoms) were similarly pyrolyzed at 1200-1460 K. Progress of the reaction was followed by analysis for H and D atoms by using resonance absorption spectroscopy. For the reaction C/sub 6/D/sub 5/CD/sub 3/ ..-->.. C/sub 6/D/sub 5/CD/sub 2/ + D under the experimental conditions, k/sub 1D/ = 1.1 x 10/sup 14/ exp(-82000 cal/RT) s/sup -1/. After allowance for isotope effects and unimolecular falloff, the high-pressure rate constant for the reaction C/sub 6/H/sub 5/CH/sub 3/ ..-->.. C/sub 6/H/sub 5/CH/sub 2/ + H is calculated to be k/sub 1infinity/. For the reaction D + C/sub 6/D/sub 5/CD/sub 3/ ..-->.. C/sub 6/D/sub 5/CD/sub 2/ +- D/sub 2/, K/sub 2D2/ = 2.1 x 10/sup 15/ exp(-15000 cal/RT) mol/sup -1/ cm/sup 3/ s/sup -1/ over the range 1300-1800 K, with an uncertainty of a factor of 1.5, while after correction for isotope effects the rate constant for H + C/sub 6/H/sub 5/CH ..-->.. C/sub 6/H/sub 5/CH/sub 2/ + H/sub 2/ over the range 600-1800 K can be expressed by the non-Arrhenius equation k/sub 2/ = 7.6 x 10/sup -5/T/sup 5.5/ exp(-340 cal/RT) mol/sup -1/ cm/sup 3/ s/sup -1/, with an uncertainty of a factor of 2. Data were also obtained on the exchange reaction by which H atoms add to the ring of C/sub 6/D/sub 5/CD/sub 3/, and D atoms are eliminated. For this reaction k/sub 4D = 3.5 x 10/sup 13/ exp(-3700 cal/RT) mol/sup -1/ cm/sup 3/ s/sup -1/ in the range 1200-1500 K, with an estimated uncertainty of a factor of 1.5. 15 references, 4 figures.

• Research Organization: Wright State Univ., Dayton, OH
• OSTI ID: 6155388
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:19; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

2-2-DIMETHYLPROPANE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ABSORPTION SPECTROSCOPY
ACCURACY
ALKANES
ALKYLATED AROMATICS
ARGON
AROMATICS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DATA ANALYSIS
DECOMPOSITION
DEUTERIUM COMPOUNDS
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
INFORMATION
KINETICS
MEDIUM PRESSURE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PYROLYSIS
QUANTITY RATIO
RARE GASES
REACTION KINETICS
SPECTROSCOPY
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE
TOLUENE
VERY HIGH TEMPERATURE