摘要:

AbstractThis article is concerned with the Stern–Volmer dependence on the NO2, SO2, and CS2fluorescence self‐quenching within a wide range of pressure variations of these gases. Besides, the pressure‐dependences of the photolysis rate of these substances have been investigated. The deviations from linearity in the Stern–Volmer dependences and photolysis rate of NO2, SO2, and CS2in the highpressure region have been revealed. These deviations correspond to increasing effective rate constant of the collision quenching ofexcited molecules NO2, SO2, and CS2.A model to describe the deviations observed has been proposed. The model assumes the formation of excimer particles which may dissociate in a monomolecular way and may be quenched at collisions. The estimates of the lifetimes of excimer particles yield the values of the order of several nano

ISSN:0538-8066    

DOI:10.1002/kin.550220102

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractMeasurements rate constants for abstraction of hydrogen from ethylene by methyl and ethyl radicals relative to the corresponding rate constants for abstraction from hydrogen, over the temperature range 650–770 K, are reported. The methodis based on the effect of the addition of small quantities of hydrogen on the rates of formation of methane and ethane in the thermalchain reactions of ethylene. On the assumption that methane and ethane are formed by the following reactions:measurements of the relative rates of formation of methane and ethane in the presence and absence of hydrogen gave the following ratios of rate constants: (R= 8.314 Joule mol−1K−1)\documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} {\rm log(}k_1 /k_2) = 1.3 \pm 0.15 + 4000 \pm 2000/2.3RT \\ {\rm log(}k_3 /k_4) = 1.6 \pm 0.15 - 0 \pm 2000/2.3RT \end{array}$$\end{document}With values from the literature for

ISSN:0538-8066    

DOI:10.1002/kin.550220103

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reaction rates of ethanolysis of ionized phenyl salicylate, PS−, have been studied in the presence of different concentrations of various inorganic and organic salts in ethanol‐water solvent of different compositions. The observed pseudo first‐order rate constants,

ISSN:0538-8066    

DOI:10.1002/kin.550220104

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractUsing a relative rate technique, rate constants for the gas‐phase reactions of the OH radical with the three cresols and the six dimethylphenols have been determined at 296 ± 2 K and atmospheric pressure. The rate constants for the cresols, which range from 4.3 × 10−11cm3molecule−1s−1to 6.8 × 10−11cm3molecule−1s−1, are in good agreement with previous literature data. The rate constants for 2,3‐, 2,4‐, 2,5‐, 2,6‐, and 3,4‐dimethylphenol are all in the range (6.6–8.1) × 10−11cm3molecule−1s−1, with the rate constant for 3,5‐dimethylphenol being somewhat higher at 1.13 × 10−10cm3molecule−1s−1. Rate constants estimated from the number, identity, and positions of the substituent groups around the aromatic ring agree to within a factor of approximately 2 with th

ISSN:0538-8066    

DOI:10.1002/kin.550220105

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractExcitation of Ru(bipy)32+ion by visible radiation of wavelength λ = 436 nm in aqueous medium in presence of inorganic peroxides, peroxomonosulfate (PMS), peroxodisulfate (PDS), and peroxodiphosphate (PDP) was found to generate Ru(bipy)33+. The kinetics of this photochemical oxidation of Ru(bipy)32+by each peroxide was followed spectrophotometrically and found to obey a total second‐order, first‐order each in [Ru(bipy)32+] and [peroxide]. In the absence of light, thermal reaction of PMS and PDS with Ru(bipy)32+occurred but only when at 1.0 M [H+] and>10−2M [peroxide]. The reaction of PMS with the complex is found to be cyclic, ie., Ru(bipy)33+formed oxidizes PMS itself and such a reaction was not observed in the case of PDS and PDP. The effects of pH, [peroxide], and [Ru(bipy)32+] on the visible light induced oxidation of Ru(bipy)32+by these peroxides are investigated. The results are discussed with suitable reaction mech

ISSN:0538-8066    

DOI:10.1002/kin.550220106

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe kinetics of oxidation of cyclohexanone(chxn), 2‐butanone(but), and 1,3‐dihydroxy‐2‐propanone (dhp) have been investigated in aqueous acidic media. A first‐order dependence in complex is obtained at high acid and low oxidant concentration for these ketones. However, a zero‐order rate prevails at high oxidant and low acid concentration, and this rate has been shown to be the acid catalyzed enolization rate of the ketone. A general rate expression has been derived to explain these behaviors and plausible mechanism has been offered by assuming the enol as the react

ISSN:0538-8066    

DOI:10.1002/kin.550220107

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550220108

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550220101

出版商:John Wiley&Sons, Inc.    

年代:1990

数据来源: WILEY