A5069741229- Atmospheric chemistry and aerosols
- Advanced Chemical Physics Studies
- Atmospheric Ozone and Climate
- Catalytic Processes in Materials Science
- Spectroscopy and Laser Applications
- Free Radicals and Antioxidants
- Catalysis and Oxidation Reactions
- Various Chemistry Research Topics
- Advanced Combustion Engine Technologies
- Photochemistry and Electron Transfer Studies
- Inorganic and Organometallic Chemistry
- Electrochemical Analysis and Applications
- Chemical Thermodynamics and Molecular Structure
- Atmospheric and Environmental Gas Dynamics
- Photoreceptor and optogenetics research
- Thermal and Kinetic Analysis
- Atmospheric aerosols and clouds
- VLSI and Analog Circuit Testing
- History and advancements in chemistry
- Analytical Chemistry and Sensors
- bioluminescence and chemiluminescence research
- Molecular Spectroscopy and Structure
- Zeolite Catalysis and Synthesis
- Oxidative Organic Chemistry Reactions
- Chemical Reactions and Mechanisms
Acadia University
2005-2023
University of Alberta
2010
British Antarctic Survey
1999-2006
Natural Environment Research Council
1999
University of British Columbia
1979
National Research Council Canada
1979
Johns Hopkins University Applied Physics Laboratory
1970
Olin Corporation (United States)
1963
The interaction of ozone with alumina has been examined at ambient temperature as a function concentration and relative humidity. experiments used diffuse reflectance FTIR spectroscopy in small flow reactor, which provided control the temperature, pressure, composition gas mixture to sample was continuously exposed. Treatment produced new spectroscopic feature 1380 cm-1, we attribute an aluminum oxide species formed by O3 Lewis acid sites on surface. After exposure stopped, subsequent...
ADVERTISEMENT RETURN TO ISSUEArticleNEXTRadical reactions in an electron spin resonance cavity homogeneous reactorArthur A. Westenberg, Newman De Haas, and J. M. RoscoeCite this: Phys. Chem. 1970, 74, 19, 3431–3438Publication Date (Print):September 1, 1970Publication History Published online1 May 2002Published inissue 1 September 1970https://pubs.acs.org/doi/10.1021/j100713a001https://doi.org/10.1021/j100713a001research-articleACS PublicationsRequest reuse permissionsArticle...
Abstract The origin of autocatalysis in the pyrolysis methane has been investigated by kinetic modeling. A mechanism is presented that provides good agreement with experimental data at 1038 K and 433 torr into autocatalytic region. main causes are secondary initiation hydrocarbon products larger than C 2 H 6 chain radical methylation sequences.
The reactions of O( 3 P) with CH OH and C 2 H 5 were studied as a function temperature. absolute rate constants for these fit the following expressions:[Formula: see text](Activation energies are in kJ/mol. Rate 1 mol −1 s .) data support abstraction α-H atom primary step. α-C—H bond ethanol is apparently weaker than that methanol, this alters nature subsequent steps mechanisms reactions. presence oxygen stoichiometric coefficients produces corresponding carboxylic acid.
The reactions of Cl with tetrahydrofuran, tetrahydropyran, and dimethyl ether have been studied as a function temperature, pressure, O(2) concentration. temperature was varied from approximately 280 to 360 K, the mole fraction ranged zero 0.6, experiments were made in bath argon at total pressures ranging 300 760 Torr. rate coefficients measured using relative method gas chromatographic analysis. reaction isobutane reference reaction, for which calibrated against propane chlorine atoms...
Abstract. The Royal Society expedition to Antarctica established a base at Halley Bay, in support of the International Geophysical Year 1957–1958. Surface ozone was measured during 1958 only, using prototype Brewer-Mast sonde. envelope maximum an annual cycle from 10 ppbv January 22 August. These values are 35% less start year and 15% end than modern Neumayer, also coastal site. This may reflect general increase surface since differences summer windy site Halley, or it loss on inlet together...
The reactions of O( 3 P) with n-propanol and isopropanol were studied as a function temperature. absolute rate constants for these reactions, in the units M −1 s , obey following relations.[Formula: see text]The activation energies are similar to those corresponding methanol ethanol, although some dependence on strength α-C—H bond is discernible. nearly constant pre-exponential factors methanol, n-propanol, suggest that no special steric effects present compounds P). Mechanisms discussed
The rate constants for the reactions of atomic bromine with dimethyl ether and diethyl were measured from approximately 300 to 350 K using relative method. Both isooctane isobutane used as reference reactants, these hydrocarbons each other over same temperature range. kinetic measurements made by photolysis dilute mixtures bromine, reactant, test reactant in argon oxygen at a total pressure 1 atm. resulting ratios combined absolute constant function reaction Br calculate isooctane, ether,...
The rate coefficients for the reactions of atomic bromine with toluene, tetrahydrofuran, and tetrahydropyran were measured from approximately 295 to 362 K using relative method. Iso-octane was used as reference compound reaction iso-octane toluene compounds tetrahydrofuran; tetrahydrofuran tetrahydropyran. found be unaffected by changes in pressure oxygen concentration. coefficient ratios converted absolute values Br compound. coefficients, units cm(3) molecule(-1) s(-1), are given k(T) =...
The rate coefficients for the reaction of 1,4-dioxane with atomic chlorine were measured from T = 292-360 K using relative method. reference reactant was isobutane and experiments made in argon produced by photolysis small concentrations Cl2. put on an absolute basis published temperature dependence reaction. Cl found to be independent total pressure p 290 782 Torr. experimentally showed a weak dependence, given k(exp)(T) (8.4(-2.3)(+3.1)) × 10(-10) exp(-(470 ± 110)/(T/K)) cm3 molecule (-1)...
Abstract The photolysis of mixtures acetone and propylene at 308 nm has been studied kinetically from approximately 300 K to 580 K. Rate constants were calculated for the reactions equation image total pressures ranging 110 torr 750 [C 3 H 6 ]/[(CH ) 2 CO] ratios in range 0.03 3.3. No dependence rate on pressure or this concentration ratio could be detected within conditions. temperature is given by © 1994 John Wiley & Sons, Inc.
The reactions of active nitrogen with CH 3 OH, C 2 H 5 n-C 7 OH and iso-C have been studied as a function temperature. rate constants for these fit the following expressions:[Formula: see text](Activation energies are in kJ/mol. Rate 1 mol −1 s .)Experiments OD, CD OD indicate small primary isotope effect secondary CH. This, other data, implies that abstraction atom from alcohol is not an important initial step.Consumption N atoms ranged 4.7 to 7.1 times consumed. With exception reaction...
Kinetic modelling is used in conjunction with measurements of product yields to develop a mechanism for the pyrolysis ethylene at 896K and pressures ranging from approximately 3 78 kPa. An induction period was observed all products except H2, followed by steady rate, which second-order 1,3-C4H6, most abundant product. The quantitatively accounts CH4, C2H6, C3H6, 1-C4H8 1,3-C4H6. reaction initiated disproportionation C2H4 1,3-C4H6 results decomposition C4H7 radical, formed addition C2H3 C2H4....
A kinetic model is presented for the pyrolysis of ethylene at pressures ranging from 0.8 to 27 kPa and temperatures 774 1023 K. The based on experimental measurements C 2 H , 6 3 1-C 4 8 1,3-C . In this temperature range reaction initiated by disproportionation observed products result reactions 5 radicals produced in process. while exclusively decomposition radical. This process its falloff region throughout conditions examined yield provides a measure degree falloff. production controlled...
The kinetics of the reactions atomic bromine with ethene, 2-methylpropane, dimethyl ether, and diethyl ether have been studied at 298 K in a 70-L photochemical reaction chamber relative rate method. Chemical analysis was by gas chromatography flame ionization detector. effects oxygen partial pressure choice reference reactant on numerical values constants obtained evaluated. results are analyzed to obtain limiting constant ratio that independent concentration O2 do not depend mechanism used...
The rate coefficient for the reaction of atomic bromine with 1,4-dioxane was measured from ∼300 to 340 K using relative method. Iso-octane and iso-butane were used as reference compounds, experiments made in a bath argon containing up 210 Torr O2 at total pressures between 200 820 Torr. coefficients not affected by changes pressure or concentration over our range experimental conditions. ratios dioxane compound put on an absolute basis published reactions. variation experimentally determined...
The kinetic behaviour for the reaction of atomic bromine with tetrahydrofuran has been analysed using information from quantum chemical calculations. Structures and energy profiles were first obtained density functional theory (DFT) employing Dunning’s basis sets triple-zeta quality, then an accurate energetic description, single-point calculations carried out at coupled-cluster single double excitations (CCSD) fourth-order Møller–Plesset (MP4(SDQ)) levels theory. rate coefficients...
The reactions of O( 3 P) with acetonitrile and propionitrile have been studied kinetically in the gas phase as a function temperature nitrile concentration. rate constants obtained experimentally for consumption these reactions, units L mol −1 s , obey following relations: O + acetonitrile: In k = 20.98 ± 0.23 − 2100 200/T; propionitrile: 21.01 0.19 1900 200/T. Mechanisms are discussed which reaction is initiated by hydrogen atom abstraction initiation addition to nitrile, followed...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProduct ratios in the photolysis of cis- and trans-glyoxal at low pressures: mechanisms thermal photochemical decompositionsJ. M. Roscoe R. A. BackCite this: J. Phys. Chem. 1986, 90, 4, 598–602Publication Date (Print):February 1, 1986Publication History Published online1 May 2002Published inissue 1 February 1986https://pubs.acs.org/doi/10.1021/j100276a023https://doi.org/10.1021/j100276a023research-articleACS PublicationsRequest reuse...
The pyrolysis of vinyl bromide has been examined in the temperature range 637−733 K and at pressures from 6 to 86 kPa. yields major hydrocarbon products, C2H2, C2H4, 1,3-C4H6, are second order over entire temperatures investigated. At higher temperatures, initiation by molecular elimination HBr dominates, while lower a free radical channel becomes increasingly important. Our data for overall process leading fit relation ln(k) = (30.7 ± 4.8) − ((26.6 3.3) × 103)/T, with rate constant units L...
Abstract The temperature dependence of the rate coefficients for reactions Cl with toluene and xylenes was examined from 290 to 362 K. Chemical analysis by gas chromatography. relative method used kinetic analysis, were converted absolute values using reference obtained recent critical evaluations. Most measurements made at a total pressure approximately 100 kPa in argon. There very little dependence, variation concentration O 2 had no effect. independent reaction used. studied isobutane,...
A detailed theoretical analysis of the reaction atomic bromine with tetrahydropyran (THP, C5H10O) was performed using several ab initio methods and statistical rate theory calculations. Initial geometries all species involved in potential energy surface title were obtained at B3LYP/cc-pVTZ level theory. These molecular reoptimized three different meta-generalized gradient approximation (meta-GGA) functionals. Single-point energies stationary points by employing coupled-cluster single double...