Kinetics of the reactions of halogenated methyl radicals (CF3, CF2Cl, CFCl2, and CCl3) with molecular chlorine

1986 ◽  
Vol 18 (10) ◽  
pp. 1193-1204 ◽  
Author(s):  
Raimo S. Timonen ◽  
John J. Russell ◽  
David Gutman
Keyword(s):  
Methyl Radicals ◽  
Molecular Chlorine ◽  
Kinetics Of

Kinetics of the reactions of partially halogenated methyl radicals (CH2Cl, CH2Br, CH2I and CHCl2) with molecular chlorine

1991 ◽  
Vol 95 (26) ◽  
pp. 10688-10693 ◽  
Author(s):  
J. A. Seetula ◽  
D. Gutman ◽  
P. D. Lightfoot ◽  
M. T. Rayes ◽  
S. M. Senkan
Keyword(s):  
Methyl Radicals ◽  
Molecular Chlorine ◽  
Kinetics Of

Kinetics of the reaction of methyl radicals with nitrogen dioxide

1981 ◽  
Vol 83 (2) ◽  
pp. 409-412 ◽  
Author(s):  
Fumiaki Yamada ◽  
Irene R. Slagle ◽  
D. Gutman
Keyword(s):  
Nitrogen Dioxide ◽  
Methyl Radicals ◽  
Kinetics Of

Reactions of free radicals with aromatic compounds in the gaseous phase. I. Kinetics of the reaction of methyl radicals with toluene

1964 ◽  
Vol 17 (12) ◽  
pp. 1329 ◽  
Author(s):  
MFR Mulcahy ◽  
DJ Williams ◽  
JR Wilmshurst
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Methyl Group ◽  
Benzyl Radical ◽  
Toluene Molecule ◽  
Benzyl Radicals ◽  
Butyl Peroxide ◽  
Kinetics Of

The kinetics of abstraction of hydrogen atoms from the methyl group of the toluene molecule by methyl radicals at 430-540�K have been determined. The methyl radicals were produced by pyrolysis of di-t-butyl peroxide in a stirred-flow system. The kinetics ,agree substantially with those obtained by previous authors using photolytic methods for generating the methyl radicals. At toluene and methyl-radical concentrations of about 5 x 10-7 and 10-11 mole cm-3 respectively the benzyl radicals resulting from the abstraction disappear almost entirely by combination with methyl radicals at the methylenic position. In this respect the benzyl radical behaves differently from the iso-electronic phenoxy radical, which previous work has shown to combine with a methyl radical mainly at ring positions. The investigation illustrates the application of stirred-flow technique to the study of the kinetics of free-radical reactions.

Kinetics of the chlorination of azobenzene and comparison with azoxybenzene

1984 ◽  
Vol 37 (11) ◽  
pp. 2249
Author(s):  
KA Ahmed ◽  
PJ Hanhela ◽  
M Hassan ◽  
J Miller ◽  
DB Paul
Keyword(s):  
Nucleophilic Substitution ◽  
Kinetic Data ◽  
Electrophilic Substitution ◽  
Relative Rate ◽  
Molecular Chlorine ◽  
Partial Rate ◽  
Reaction Proceeds ◽  
Kinetics Of ◽  
No Activation

The activating effect of the phenylazo substituent in electrophilic substitution has been examined. The rates and partial rate factors for chlorination of azobenzene with molecular chlorine and protonated chlorine acetate have been determined relative to benzene. Whereas the chlorine acetate reaction proceeds readily (relative rate 4900) there is virtually no activation to chlorination by molecular chlorine. Complexes between azobenzene and bromine were, however, isolated and chatacterized. Their formation implies that during molecular halogenation reactions the electrophile is essentially unavailable. The relative chlorination rates for azobenzene and azoxybenzene have also been established: the phenylazo group is more activating towards protonated chlorine acetate whereas azoxybenzene (which does not complex with halogens) is the more reactive with molecular chlorine. The chlorination results confirm the versatility of the phenylazo group which is the first substituent for which kinetic data have been obtained quantifying activation of aromatic electrophilic, radical and nucleophilic substitution.

Examination of Gallium Arsenide Mocvd Reaction Mechanisms

1993 ◽  
Vol 312 ◽  
Author(s):  
Robert S. Windeler ◽  
Robert F. Hicks
Keyword(s):  
Gallium Arsenide ◽  
Reaction Mechanisms ◽  
Film Growth ◽  
Methyl Radicals ◽  
Decomposition Rates ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Precursor Decomposition ◽  
Rate Limiting ◽  
Kinetics Of

AbstractA mathematical model has been developed of the reactor used by Larsen et al. [1] to study the kinetics of gallium arsenide MOCVD.- Two different surface reactions were considered as the rate-limiting step in film growth below 500°C: (1) the desorption of methyl radicals from adsorbed trimethylgallium, and (2) the reaction of CH3 and H groups from adsorbed trimethylgallium and arsine to make methane. The latter step is consistent with the experimental results. It explains the rapid acceleration of the precursor decomposition rates when they are fed together to the reactor. It also explains why methane is the only hydrocarbon generated from trimethylgallium and arsine decomposition in deuterium at V/Ill ratios greater than 1.0.

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