Trospospheric degradation chemistry of HCFC-123 (CF3CHCl2): A proposed replacement chlorofluorocarbon
作者:G.D. Hayman、M.E. Jenkin、T.P. Murrells、C.E. Johnson
DOI:10.1016/1352-2310(94)90121-x
日期:1994.2
time-resolved ultra-violet absorptionspectroscopy for the kinetic measurements and broad-band ultra-violet absorptionspectroscopy for product characterization. Rate coefficients have been determined for the self-reaction of CF 3 CCl 2 O 2 as (3.6±0.5)×10 −12 cm 3 mol −1 s −1 and for its reactions with HO 2 and NO as (1.9±0.7)×10 −12 cm 3 mol −1 s −1 and (1.5–2.0)×10 −11 cm 3 mol −1 s −1 , respectively, at room
摘要 HCFC-123 已被提议作为部分完全卤化的氯氟烃和其他氯化烃的替代品,后者正在根据蒙特利尔议定书逐步淘汰。本文报告了实验室研究,这些研究旨在确定 HCFC-123 大气降解所涉及的反应的动力学和机械参数,并在对流层的二维全球模型中使用这些参数来评估降解过程中形成的产物的产量。实验研究利用激光闪光光解技术和时间分辨紫外吸收光谱进行动力学测量和宽带紫外吸收光谱进行产品表征。CF 3 CCl 2 O 2 自反应的速率系数已确定为 (3.6±0. 5)×10 -12 cm 3 mol -1 s -1 及其与HO 2 和NO的反应为(1.9±0.7)×10 -12 cm 3 mol -1 s -1 和(1.5-2.0)×10 -在室温下分别为 11 cm 3 mol -1 s -1 。还获得了 CF 3 CCl 2 O 2 与 C 2 H 5 O 2 反应的动力学数据,并确定了两个通道;CF
Rate constants for the reactions of C2H5, C2H5O and C2H5O2 radicals with NO3 at 298 K and 2.2 torr
作者:Peter Biggs、Carlos E. Canosa-Mass、Jean-Marc Fracheboud、Dudley E. Shallcross、Richard P. Wayne
DOI:10.1039/ft9959100817
日期:——
ethoxyl radical and an optical absorption cell to detect the nitrate radical has been used to measure the rateconstants for the reactionsC2H5+ NO3→ products (1), C2H5O + NO3→ products (2), C2H5O2+ NO3→ products (3), at T= 298 K and P= 2.2 Torr. The major products of these reactions are C2H5O and NO2 for reaction (1), C2H5O2 and NO2 for reaction (2) and C2H5O, O2 and NO2 for reaction (3). Reactions (2)
装有激光感应荧光池以检测乙氧基自由基和光吸收池以检测硝酸根自由基的排气系统已用于测量反应C 2 H 5 + NO 3 →产物的速率常数(1 ),C 2 H 5 O + NO 3 →产物(2),C 2 H 5 O 2 + NO 3 →产物(3),在T = 298 K和P = 2.2托时。这些反应的主要产物是C 2 H 5 O和反应(1)的NO 2 C 2 H 5Ò 2和NO 2进行反应(2)和C 2 ħ 5 O,O- 2和NO 2为反应(3)。因此,反应(2)和(3)是高度偶联的,并且为了确定这些反应的速率常数k 2和k 3,进行了两种类型的实验。在第一组实验中,通过反应(1)原位生成C 2 H 5 O,并使其与NO 3反应;在第二组实验中,C 2 H 5 O 2单独产生的NO 3与NO 3反应。然后使用数值模型得出以下速率常数:k 1 =(4.0±1.0)×10 –11 cm 3分子–1 s
Reactions of oxygenated radicals in the gas phase. Part 10.—Self-reactions of ethylperoxy radicals
作者:Christopher Anastasi、David J. Waddington、Allan Woolley
DOI:10.1039/f19837900505
日期:——
The photo-oxidation of azoethane has been studied by molecular modulation spectroscopy in order to determine the overall rate constant for the second-order removal of ethylperoxy radicals between 303 and 457 K. The principal molecular products of the reaction between 302 and 373 K are acetaldehyde, ethanol and ethyl hydroperoxide. From the reaction rate data and analytical results, the following results
为了确定在303和457 K之间二次除去乙基过氧自由基的总速率常数,已经通过分子调制光谱法研究了偶氮乙烷的光氧化反应。302和373 K之间反应的主要分子产物是乙醛,乙醇和氢过氧化乙酯。从反应速率的数据和分析结果,下面的结果已获得的反应2C 2 ħ 5 ö 2 ;· →交通CH 2 CHO + C 2 ħ 5 OH + O 2。(3一个)2C 2 ħ 5 ö 2 ;· →交通2C 2 ħ 5Ò ˙ + O 2。(3 b)k 3 b / k 3 a随着温度从302 K时的1.75±0.05升高到373 K时的2.45±0.15。随着反应(3 a)和(3 b)的阿伦尼乌斯(Arrhenius)表达式被估算。
Kinetics of the Cross Reactions of CH<sub>3</sub>O<sub>2</sub> and C<sub>2</sub>H<sub>5</sub>O<sub>2</sub> Radicals with Selected Peroxy Radicals
作者:Eric Villenave、Robert Lesclaux
DOI:10.1021/jp960765m
日期:1996.1.1
be between the rate constants for the self-reactions of RO2 and CH3O2 (or C2H5O2). However, when the RO2 self-reaction is fast, the cross reaction with CH3O2 (or C2H5O2) is also fast, with similar rate constants for both reactions, suggesting that these particular peroxy radical cross reactions can play a significant role in the chemistry of hydrocarbon oxidation processes in the troposphere and in
使用两种技术研究了选定的过氧自由基(RO 2)与CH 3 O 2和与C 2 H 5 O 2的反应动力学:准分子激光光解法和常规闪速光解法,均与紫外吸收光谱法结合。在适当的烃存在下,通过分子氯的光解或通过适当的烷基氯的光解,产生自由基。除烯丙基过氧自由基与CH 3 O 2的反应外,所有此类交叉反应动力学均在760 Torr总压力和室温下进行。,对于将其291和423之间所确定的速率常数K,从而产生以下速率表达式: ķ 15 =(2.8±0.7)×10 -13 EXP [(515±75)/ Ť ]厘米3分子-1小号- 1。(2.0±0.5)×10 -13,(1.5±0.5)×10 -12,(9.0±0.15)×10 -14,<2.0×10 -12,(2.5±0.5)×10 -12,和CH 3 O 2的反应获得了(8.2±0.6)×10 -12(cm 3分子-1 s -1的单位)。具有C 2 H
Kinetics and mechanism of the C<sub>2</sub>H<sub>5</sub>O<sub>2</sub>+ NO reaction: A temperature and pressure dependence study using chemical ionization mass spectrometry
作者:Max W. Bardwell、Asan Bacak、M. Teresa Raventós、Carl J. Percival、Gabriela Sanchez-Reyna、Dudley E. Shallcross
DOI:10.1002/kin.20078
日期:2005.4
The overall rate coefficient (k1) for the reaction of C2H5O2 + NO has been measured using the turbulent flow CIMS technique. The temperaturedependence of the rate coefficient was investigated between 203 and 298 K. Across the temperature range, the experimentally determined rate coefficients showed good agreement with previous studies and were fitted using an Arrhenius type analysis to yield the expression