摘要:

AbstractAn upper limit for the reaction rate of CO with the nitrate radical NO3has been determined equal to 4 × 10−19cm+3molec−1s−1at 295 ± 2 K. In the experiment the isotopic species C13O16and C13O18mixed at 1–2 ppmv level in synthetic air have been reacted with NO3and the reaction followed using long path infrared absorption FT spectroscopy. The result is of interest in the studies on the role played by NO3in nighttime tropospheric

ISSN:0538-8066    

DOI:10.1002/kin.550180802

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe thermal decomposition of diethyl ether was studied in the temperature range 697.2–760.5 K. The rate constant of reaction (1), and the ratio of the rate constant of reaction (2) to that of (12):were calculated from the amounts of products:\documentclass{article}\pagestyle{empty}\begin{document}$$ \log k_1 ({\rm s}^{{\rm - 1}}) = (17.2 \pm 0.6) - (82.4 \pm 2.0{\rm kcal mol}^{{\rm - 1}})/2.3RT $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ \log k_2 /k_{12^{1/2} } ({\rm dm}^{{\rm 3/2}} {\rm mol}^{{\rm - 1/2}}) = (4.1 \pm 0.4) - (11.9 \pm 1.3{\rm kcal mol}^{{\rm - 1}})/2.3RT $$\end{documen

ISSN:0538-8066    

DOI:10.1002/kin.550180803

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinetics of the gas phase reaction of OH radicals with dimethyl sulfide (CH3SCH3) have been studied at various temperatures and total pressures using two relative rate methods and a flash photolysis technique. For the relative rate methods, rate constants were measured at 296 ± 2 K as a function of the O2pressure at a total pressure of ca. 740 torr. Data from these three experimental techniques were not in agreement. It is concluded that the relative rate techniques are subject to secondary reactions, possibly involving CH3S radicals. A rate constant of (2.5 −0.6+0.9) × 10−12e(130 = 102)/Tcm3molecule−1s−1obtained using the flash photolysis‐resonance fluorescence data in the absence of O2, and which is in agreement with the lower range of values previously reported in the literature, i

ISSN:0538-8066    

DOI:10.1002/kin.550180804

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe rate constantk1for the reaction of OH radicals with CIO2molecules was measured in a discharge flow system over the temperature range 293 ≤T≤ 473 K and at low pressures, 0.5 ≤P≤ 1.4 torr, using electron paramagnetic resonance or laser‐induced fluorescence to monitor the pseudo first‐order decay of OH concentrations. At 293 K, the value obtained fork1was (7.2 ± 0.5) × 10−12cm3molecule−1s−1. Within the temperature range of this study, a negative temperature dependence was observed:k1= (4.50 ± 0.75) × 10−13exp[(804 ± 114)/T] cm3molecule−1s−1. HOCl was detected by mass spectrometry as a product of the reaction and was titrated using OH + Cl2as a source in the calibration experiments. A simulation of the mechanism of the OH + ClO2reaction indicated that HOCl was mainly produced in the first reaction step. Both this result and the observedTdependence ofk1suggest that this reaction proceeds via an intermediate a

ISSN:0538-8066    

DOI:10.1002/kin.550180805

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe chromatographic retention of H and D atoms has been observed in a quartz tube using argon as a carrier gas for D and six different gases for H. The results give equilibrium constants for the reversible adsorption of H and D on quartz as well as the rates of desorption. Self‐consistent conclusions can be drawn from the data. The adsorption energy appears to be ca. 50 kJ mol−1indicating weak chemisorption. The observations are consistent with vibration frequencies on the surface of around 700–900 cm−1for D. and around 1000–1300 cm−1for H. It appears that only a fraction of the surface atoms (ca. 10−2) act as ads

ISSN:0538-8066    

DOI:10.1002/kin.550180806

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe bimolecular reactions in the title were measured behind shock waves by monitoring the O‐atom production in COSO2Ar and CS2O2Ar mixtures over the temperature range between 1400 and 2200 K. A value of the rate constant for S + O2→ SO + O was evaluated to be (3.8 ± 0.7) × 1012cm3mol−1s−1between 1900 and 2200 K. This was connected with the data at lower temperatures to give an expressionk2= 1010.85T0.52cm3mol−1s−1between 250 and 2200 K. An expression of the rate constant for CS2+ O2→ CS + SO2was obtained to bek21= 1012.0exp(−32 kcal mol−1/RT) cm3mol−1s−1with an error fact

ISSN:0538-8066    

DOI:10.1002/kin.550180807

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractRate constants have been determined at (298 ± 4) K for the reactions:and the relaxation processes:Time‐resolved HF(1,0) emission was observed following the photolysis of F2with pulses from an excimer laser operating on XeCl (λ = 308 nm). Analysis of the emission traces gave first‐order constants for reaction and relaxation, and their dependence on [H2O] and [HCN]yielded:\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{1{\rm a}} = (1.3 \pm 0.1) \times 10^{ - 11} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} s^{ - 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{1{\rm b}} = (1.3 \pm 0.1) \times 10^{ - 10} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} s^{ - 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{2{\rm a}} = (3.7 \pm 0.4) \times 10^{ - 13} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} s^{ - 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{2{\rm b}} = (3.4 \pm 0.2) \times 10^{ - 12} {\rm cm}^{\rm 3} {\rm molecule}^{{\rm - 1}} s^{ - 1} $$\end{doc

ISSN:0538-8066    

DOI:10.1002/kin.550180808

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe pertechnetate ion oxidizes ascorbic acid in strong acid medium to form red species. A reaction mechanism has been developed which correctly predicts all the experimental facts. The results obtained support the postulate according to which the red species corresponds to a complex formed between Tc(V) and dehydroascorbic acid. The rate constants and Arrhenius parameters have been investigated.

ISSN:0538-8066    

DOI:10.1002/kin.550180809

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinetics of the gas phase reaction between NO2and CF2CCl2has been investigated in the temperature range from 50 to 80°C. The reaction is homogeneous. Three products are formed: O2NCF2CCl2NO2and equimolecular amounts of CINO and of O2NCF2C(O)Cl. The rate of consumption of the reactants is independent of the total pressure, the reaction products, and added inert gases and can be represented by a second‐order reaction:\documentclass{article}\pagestyle{empty}\begin{document}$$ - \frac{{d[{\rm NO}_{\rm 2}]}}{{dt}} = - 2\frac{{d[{\rm CF}_{\rm 2} {\rm CCI}_{\rm 2}]}}{{dt}} = k[{\rm NO}_{\rm 2}][{\rm CF}_{\rm 2} {\rm CCI}_{\rm 2}] $$\end{document}However, the distribution of the products is influenced by the pressure of the present gases, which favor the formation of the dinitro‐compound in a specific way. The effect of CF2CCl2is the greatest. In the absence of added gases, the ratio of O2NCF2CCl2NO2to that of O2NCF2C(O)Cl is proportional to (CF2CCl2+ γPproducts).The experimental results can be explaned by the following mechanism:PandXrepresent the products and the added gases:\documentclass{article}\pagestyle{empty}\begin{document}$$ - \frac{{d[{\rm NO}_{\rm 2}]}}{{dt}} = - 2\frac{{d[{\rm CF}_{\rm 2} {\rm CCI}_{\rm 2}]}}{{dt}} = k_1 [{\rm NO}_{\rm 2}][{\rm CF}_{\rm 2} {\rm CCI}_{\rm 2}] $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_1 = 3.16 \pm 0.5 \times 10^6 \exp ( - 10500 \pm 1000{\rm cal/}RT){\rm M}^{{\rm - 1}} {\rm s}^{{\rm - 1}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm \gamma }_{{\rm CF}_{\rm 2} {\rm CCI}_{\rm 2} } :{\rm \gamma }_P :{\rm \gamma }_{{\rm C}_{\rm 2} {\rm F}_{\rm 5} {\rm CI}} :{\rm \gamma }_{{\rm CCL}_{\rm 3} } :{\rm \gamma }_{{\rm CF}_{\rm 4} } :{\rm \gamma }_{{\rm N}_{\rm 2} } = 1:0.22:0.15:0.14:0.054:0.015 $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm \gamma }_{{\rm NO}_{\rm 2} } < 0.01 $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_3 = 1.4 \pm 0.3 \times 10^8 {\rm s}^{{\rm - 1}} $$\end{doc

ISSN:0538-8066    

DOI:10.1002/kin.550180810

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550180801

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY