摘要:

AbstractThe unimolecular decomposition of 2,2 dimethyloxetance to give either isobutence and formaldehyde or ethene and acetone induced by a pulsed CO2laser has been investigated. Absorption characteristics and fractional decomposition have been studied as a function of laser fluence, irradiation frequency, reactant pressure, and added inert bath gas. Both absorption cross section and fractional decomposition are approximately independent of pressure of 2,2‐dimethyloxetane below 50 times; 10−3torr and increase with pressure at higher pressures of 2,2‐dimethyloxetane. At pressures sufficiently low that collisions are negligible during the laser pulse, added inert gases reduce the amount of decomposition. Calculations of the fractional decomposition have been carried out based on RRKM theory and assuming either a Boltzmann or a Poisson intermolecular energy distribution. Master equation calculations of both absorption and decomposition for 10R20 irradiation have also been performed. Agreement between observed and calculated results for 10R20 irradiation could be obtained only by assuming that most, but not all, of the molecules in the irradiated volume absorb the laser radiation. Differences between the absorptions of the 10R20 and 9P20 lines and in the resulting extents of decomposition indicate that the fraction of irradiated molecules which absorbs 9P20 radiation is smaller than the fraction which absorbs 10R20 radi

ISSN:0538-8066    

DOI:10.1002/kin.550181102

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinetics and mechansim for the NO2‐initiated oxidation of tetramethyl ethylene (TME) have been studied using the FTIR spectroscopic method in mixtures containing NO2and TME (0.1−1.0 Torr) and N2O2(700 Torr) at 298 ± 2 K. While TME decayed according to ‐d[TME]/dt=kobs[NO2][TME], NO2exhibited a complex kinetic behavior. Furthermore, values ofkobswere dependent on [O2]. Among the products were (CH3)2CO and at least three NO2‐containing compounds. These results indicate the formation of a nitro‐alkylperoxy radical via reactions (1), (−1), and (2), and its subsequent reactions leading to the observed products.The [O2]‐dependence ofkobsyieldedk1= (1.07 ± 0.15) × 10−20cm3molecule−1S−1andk−1/k2= (3.54

ISSN:0538-8066    

DOI:10.1002/kin.550181103

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe decomposition reactions ofN‐bromodiethanolamine,N‐bromoethylethanolamine, andN‐bromomethylethanolamine in aqueous solution have been studied kinetically under various experimental conditions. The results support a proposed reaction mechanism in which the rate controlling step is assumed to be the formation of an imine which is then hydrolyzed to the final decomposition pro

ISSN:0538-8066    

DOI:10.1002/kin.550181104

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractA test of the Kassel quantum expressions for unimolecular rate constants and densities of vibrational states is described. Rate constants are calculated for nine reactions previously used in such tests, over a wide range of temperatures and pressures. The Kassel expression using the geometric mean of the molecular vibration frequencies is generally found to give better results than that using the arithmetic mean.

ISSN:0538-8066    

DOI:10.1002/kin.550181105

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractWe have studied the oxidation of benzyl alcohols by nitrous and nitric acid in sulfuric acid media. The oxidation by nitrous acid is rapid and has an activation energy of 10.6 ± 0.8 kcal mol−1. A Hammett plot of logk2vs. σ+is linear with a ρ value of −1.4. The oxidation by nitric acid in sulfuric acid media is autocatalytic. From the kinetic and product analyses, it is concluded that a common oxidant, the nitrosonium ion is involved when either nitrous or nitric acid is used. A mechanism is proposed which involves the abstraction of hydride from the alcohols as the rate determining step. It is demonstrated that the autoxidation of the alcohols is catalyzed by nitrous acid or nitric

ISSN:0538-8066    

DOI:10.1002/kin.550181106

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe kinetics of the reaction between nitric oxide and chlorine have been investigated in both carbon tetrachloride and glacial acetic acid. The nitric oxide‐oxygen reaction has been investigated in carbon tetrachloride.The appearance of product, NOCl or NO2, was monitored spectrophotometrically at a wavelength of 475 nm for NOCl and 343 nm for NO2. These measurements were performed using an Amino‐Morrow stopped‐flow apparatus equipped with a Beckman D U monochromator.The data for both the NOCl2and NOO2systems could be fitted to the third‐order integrated equation and the calculated rate constants were 2.75 × 103M−2s−1and 2.79 × 106M2s−1, respectively, at 25.1°C.There was a noted increase in rate constants on changing the solvent from carbon tetrachloride to acetic acid.The likelihood of a termolecular encounter is inherent in the mechanism, however, no real evidence to substantiate either a direct termolecular or a series of two bimolecular steps has been obtained, although a −7 kcal for ΔH0w

ISSN:0538-8066    

DOI:10.1002/kin.550181107

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550181101

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY