摘要:

AbstractThe thermal decomposition of propene behind reflected shock waves with 1200

ISSN:0538-8066    

DOI:10.1002/kin.550240902

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe thermal unimolecular decomposition of hex‐1‐ene‐3‐yne (HEY) has been investigated over the temperature range 949–1230 K using the technique of very low‐pressure pyrolysis (VLPP). One reaction pathway is the expected C5C6bond fission to form the resonance‐stabilized 3‐ethenylpropargyl radical. There is a concurrent process producing molecular hydrogen which probably occurs via the intermediate formation of hexatrienes and cyclohexa‐1,3‐diene. RRKM calculations yield the extrapolated high‐pressure rate parameters at 1100 K given by the expressions 1016.0±0.3exp(−300.4 ± 12.6 kJ mol−1/RT) s−1for bond fission and 1013.2+0.4exp(−247.7 ± 8.4 kJ mol−1/RT) for the overall formation of hydrogen. The A factors were assigned from the results of previous studies of related alkynes, alkenes, and alkadienes. The activation energy for the bond fission reaction leads to ΔH f300°[H2CCHCCĊH2] = 391.9,DH 300°[H2CCHCCCH2H] = 363.3, and a resonance stabilization energy of 56.9 ± 14.0 kJ mol−1for the 3‐ethenylpropargyl radical, based on a value of 420.2 kJ mol−1for the primary CH bond dissociation energy in alkanes. Comparison with the revised value of 46.6 kJ mol−1for the resonance energy of the unsubstituted propargyl radical indicates that the ethenyl substituent (CH2CH) on the terminal carbon atom has only a small effec

ISSN:0538-8066    

DOI:10.1002/kin.550240903

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractPulsed laser photolysis, time‐resolved laser‐induced fluorescence experiments have been carried out on the reactions of CN radicals with CH4, C2H6, C2H4, C3H6, and C2H2. They have yielded rate constants for these five reactions at temperatures between 295 and 700 K. The data for the reactions with methane and ethane have been combined with other recent results and fitted to modified Arrhenius expressions,k(T) = A′(298) (T/298)nexp(−θ/T), yielding: for CH4, A′(298) = 7.0 × 10−13cm3molecule−1s−1,n= 2.3, and θ = −16 K; and for C2H6, A′(298) = 5.6 × 10−12cm3molecule−1s−1,n= 1.8, and θ = −500 K. The rate constants for the reactions with C2H4, C3H6, and C2H2all decrease monotonically with temperature and have been fitted to expressions of the form,k(T) =k(298) (T/298)nwithk(298) = 2.5 × 10−10cm3molecule−1s−1,n= −0.24 for CN + C2H4;k(298) = 3.4 × 10−10cm3molecule−1s−1,n= −0.19 for CN + C3H6; andk(298) = 2.9 × 10−10cm3molecule−1s−1,n= −0.53 for CN + C2H2. These reactions almost certainly proceedviaaddition‐elimination yielding an unsaturated cyanide and an H‐atom. Our kinetic results for reactions of CN are compared with those for reactions of the same hydrocarbons

ISSN:0538-8066    

DOI:10.1002/kin.550240904

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe kinetics of the gas‐phase reactions of O3with a series of alkenes have been investigated at atmospheric pressure (ca. 740 torr) of air and 296 ± 2 K, using a relative rate method in the presence of sufficientn‐octane to scavenge any OH radicals generated in these reactions. Relative tok(O3+ propene) = 1.00, the rate constants obtained were: 1‐butene, 0.975 ± 0.030; 2‐methylpropene, 1.14 ± 0.04; 2‐methyl‐1,3‐butadiene (isoprene), 1.21 ± 0.02; 1,4‐cyclohexadiene, 4.75 ± 0.23; cyclohexene, 7.38 ± 0.48;cis‐2‐butene, 12.8 ± 0.8;trans‐2‐butene, 21.5 ± 1.5; 2‐methyl‐2‐butene, 42.1 ± 2.8; cyclopentene, 64.9 ± 4.3; and 2,3‐dimethyl‐2‐butene, 123 ± 11. These relative rate constants have been placed on an absolute basis using a rate constant for the reaction of O3with propene of 1.01 × 10−17cm3molecule−1s−1at 296 K derived from an analysis of the available literature data. The resulting rate constants then lead to a self‐consistent set of room temperature data for the re

ISSN:0538-8066    

DOI:10.1002/kin.550240905

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractPropane oxidation in jet‐stirred reactor was modeled using a comprehensive kinetic reaction mechanism including the most recent findings concerning the kinetics of the reactions involved in the oxidation of C1C4hydrocarbons. The present detailed mechanism is able to reproduce experimental species concentration profiles obtained in our high‐pressure jet‐stirred reactor (900 ⩽ T/K ⩽ 1200; 1 ⩽ P/atm ⩽ 10; 0.15 ⩽ ϕ ⩽ 4) and in a turbulent flow reactor at 1 atm; ignition delay times measured in shock tube (1200 ⩽ T/K ⩽ 1700; 2 ⩽ P/atm ⩽ 15; 0.125 ⩽ ϕ ⩽ 2); H‐atoms concentrations measured in shock tube during the pyrolysis of propane and burning velocities of freely propagating premixed propane‐air laminar flames. The computed results are discussed in terms of pressure and equivalence ratio (ϕ) effects on propane oxidation. The same detailed kinetic reaction mechanism can also be used to model the oxidation of methane, ethylene, ethane, and propene in simi

ISSN:0538-8066    

DOI:10.1002/kin.550240906

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550240901

出版商:John Wiley&Sons, Inc.    

年代:1992

数据来源: WILEY