摘要:

AbstractRate constants for the gas‐phase reactions of the four oxygenated biogenic organic compoundscis‐3‐hexen‐1‐ol,cis‐3‐hexenylacetate,trans‐2‐hexenal, and linalool with OH radicals, NO3radicals, and O3have been determined at 296 ± 2 K and atmospheric pressure of air using relative rate methods. The rate constants obtained were (in cm3molecule−1s−1units):cis‐3‐hexen‐1‐ol: (1.08 ± 0.22) × 10−10for reaction with the OH radical; (2.72 ± 0.83) × 10−13for reaction with the NO3radical; and (6.4 ± 1.7) × 10−17for reaction with O3;cis‐3‐hexenylacetate: (7.84 ± 1.64) × 10−11for reaction with the OH radical; (2.46 ± 0.75) × 10−13for reaction with the NO3radical; and (5.4 ± 1.4) × 10−17for reaction with O3;trans‐2‐hexenal: (4.41 ± 0.94) × 10−11for reaction with the OH radical; (1.21 ± 0.44) × 10−14for reaction with the NO3radical; and (2.0 ± 1.0) × 10−18for reaction with O3; and linalool: (1.59 ± 0.40) × 10−10for reaction with the OH radical; (1.12 ± 0.40) × 10−11for reaction with the NO3radical; and (4.3 ± 1.6) × 10−16for reaction with O3. Combining these rate constants with estimated ambient tropospheric concentrations of OH radicals, NO3radicals, and O3results in calculated tropospheric lifet

ISSN:0538-8066    

DOI:10.1002/kin.550271002

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe detailed ethylene oxidation data set of Thornton [1], obtained for a well‐stirred reactor operated fuel‐lean at atmospheric pressure and for temperatures of 1003 K to 1253 K, is used as a basis for the comparison of chemical kinetic mechanisms reported in the literature and for the development of a new ethylene oxidation mechanism. The mechanisms examined are those of Westbrook and Pitz [2]and Dagaut et al. [3]. These mechanisms indicated that unusually large rates for the vinyl decomposition reaction are required to obtain agreement with the Thornton data set.A new ethylene oxidation mechanism is developed in order to overcome some of the drawbacks of the previous mechanisms. The new mechanism closely simulates the overall rate of loss of ethylene, and the concentration of CO, CO2, H2, CH2O, C2H2, CH3OH, CH4, and C2H6measured for the stirred reactor. Predictions by this mechanism are dependent on a new high temperature vinyl oxidation route,\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm C}_{\rm 2} {\rm H}_{\rm 3} + {\rm O}_{\rm 2} \, = \,{\rm CH}_{\rm 2} {\rm CHO}\,{\rm + }\,{\rm O} $$\end{document}with akC2H3+O2CH2CHO+C/kC2H3+O2CH2O+HCObranching ratio of 1.4 at 1053 K to 2.05 at 1253 K. The branching ratio values were dependent upon the extent of fall‐off for the C2H3+ O2= CH2O + HCO reaction. © 1995 John Wiley

ISSN:0538-8066    

DOI:10.1002/kin.550271003

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe reactions of the title substrates with a series of secondary alicyclic amines are subjected to a kinetic study in 44 wt% aqueous ethanol, at 25.0deg;C, ionic strength 0.2 M (maintained with KCl). Pseudo‐first‐order kinetics are found under amine excess. The order in amine obtained is one in the reactions of all amines. The Brönsted‐type plots for the overall second‐order rate coefficients are biphasic with slopes β1= 0.3 (high pKa), β2= 0.95 (low pKa) for the aminolysis of the 4‐nitro derivative, and β1= 0.3 and β2= 0.80 for the aminolysis of the dinitro compound; the pKavalues at the curvature center are pK a0= 9.8 and 9.5, respectively. From a comparison of these pK a0values with those found in the same reactions in water and the shapes of the Brönsted‐type plots, it is concluded that these reactions are stepwise, with the formation of a zwitterionic tetrahedral intermediate in the reaction pathway. © 199

ISSN:0538-8066    

DOI:10.1002/kin.550271004

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe rate coefficients for the reaction of O(3P) with the biogenic hydrocarbons Δ3‐carene, α‐pinene, and isoprene have been measured using a direct method for the first time. O(3P) was generated from the pulsed photolysis of NO2or O3at 308 nm, and measured by resonance fluorescence at 131 nm. Rate coefficients at room temperature for the biogenics are similar: (3.4 ± 0.6) × 10−11, (3.7 ± 0.6) × 10−11, and (3.5 ± 0.6) × 10−11cm3molec−1s−1, for Δ3‐carene, α‐pinene, and isoprene, respectively. The rate coefficients for the reaction of O(3P) with NO2and ethene were also measured with the same method, and these values are within 4% and 10% of the currently recommended values, respectively. The correlation between OH and O(3P)‐alkene reaction rate coefficients is updated and discussed

ISSN:0538-8066    

DOI:10.1002/kin.550271005

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractRate coefficients have been measured for the reaction of OH radicals with methylglyoxal from 260 to 333 K using the discharge flow technique and laser‐induced fluorescence detection of OH. The rate coefficient was found to be (1.32±0.30) × 10−11cm3molecule−1s−1at room temperature, with a distinct negative temperature dependence (E/R of −830 ± 300 K). These are the first measurements of the temperature dependence of this reaction. The reaction of OH with acetaldehyde was also investigated, and a rate coefficient of (1.45 ± 0.25) × 10−11cm3molecule−1s−1was found at room temperature, in accord with recent studies. Experiments in which O2was added to the flow showed regeneration of OH following the reaction of CH3CO radicals with O2. However, chamber experiments at atmospheric pressure using FTIR detection showed no evidence for OH production. FTIR experiments have also been used to investigate the chemistry of the CH3COCO radical formed by hydrogen abstraction from methylglyoxal. © 1995

ISSN:0538-8066    

DOI:10.1002/kin.550271006

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractIn the pH range 4.3–13, the reaction betweenN‐methylacetamide (NMA) and sodium hypochlorite in dilute aqueous solution to giveN‐chloro‐N‐methylacetamide (CINMA) was found to be far slower than analogous reactions affordingN‐chloramines orN‐chloroamino acids. The rate expression for chlorination was first‐order each in [NMA] and [Cltot] (the total concentration of chlorinating species). A rate constant calculated for chlorination by each chlorinating species indicated that the order of increasing reactivity was HClO

ISSN:0538-8066    

DOI:10.1002/kin.550271007

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe kinetics of base hydrolysis of (αβS) (salicylato) (tetraethylenepentamine) cobalt(III) have been investigated in aquo‐organic solvent media at 15.0

ISSN:0538-8066    

DOI:10.1002/kin.550271008

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550271001

出版商:John Wiley&Sons, Inc.    

年代:1995

数据来源: WILEY