Kinetic investigations of chlorine atom initiated photo oxidation reactions of 2,3-dimethyl-1,3-butadiene in the gas phase: an experimental and theoretical study

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 67739-67750 ◽  
Author(s):  
S. Vijayakumar ◽  
B. Rajakumar

Rate coefficients for the reaction of chlorine atoms with 2,3-dimethyl-1,3-butadiene were measured over the temperature range of 269–393 K by using a relative rate experimental method with reference to isoprene and 1-pentene.

2017 ◽  
Vol 41 (15) ◽  
pp. 7491-7505 ◽  
Author(s):  
S. Vijayakumar ◽  
C. B. Ramya ◽  
Avinash Kumar ◽  
B. Rajakumar

Cl atom initiated photo oxidation kinetics of cyclohexene and cycloheptene.


2018 ◽  
Vol 18 (6) ◽  
pp. 4039-4054 ◽  
Author(s):  
Jacob T. Shaw ◽  
Richard T. Lidster ◽  
Danny R. Cryer ◽  
Noelia Ramirez ◽  
Fiona C. Whiting ◽  
...  

Abstract. Gas-phase rate coefficients are fundamental to understanding atmospheric chemistry, yet experimental data are not available for the oxidation reactions of many of the thousands of volatile organic compounds (VOCs) observed in the troposphere. Here, a new experimental method is reported for the simultaneous study of reactions between multiple different VOCs and OH, the most important daytime atmospheric radical oxidant. This technique is based upon established relative rate concepts but has the advantage of a much higher throughput of target VOCs. By evaluating multiple VOCs in each experiment, and through measurement of the depletion in each VOC after reaction with OH, the OH + VOC reaction rate coefficients can be derived. Results from experiments conducted under controlled laboratory conditions were in good agreement with the available literature for the reaction of 19 VOCs, prepared in synthetic gas mixtures, with OH. This approach was used to determine a rate coefficient for the reaction of OH with 2,3-dimethylpent-1-ene for the first time; k =  5.7 (±0.3)  ×  10−11 cm3 molecule−1 s−1. In addition, a further seven VOCs had only two, or fewer, individual OH rate coefficient measurements available in the literature. The results from this work were in good agreement with those measurements. A similar dataset, at an elevated temperature of 323 (±10) K, was used to determine new OH rate coefficients for 12 aromatic, 5 alkane, 5 alkene and 3 monoterpene VOC + OH reactions. In OH relative reactivity experiments that used ambient air at the University of York, a large number of different VOCs were observed, of which 23 were positively identified. Due to difficulties with detection limits and fully resolving peaks, only 19 OH rate coefficients were derived from these ambient air samples, including 10 reactions for which data were previously unavailable at the elevated reaction temperature of T =  323 (±10) K.


2017 ◽  
Author(s):  
Jacob T. Shaw ◽  
Richard T. Lidster ◽  
Danny R. Cryer ◽  
Noelia Ramirez ◽  
Graham A. Boustead ◽  
...  

Abstract. Gas-phase rate coefficients are fundamental to understanding atmospheric chemistry, yet experimental data are not available for the oxidation reactions of many of the thousands of volatile organic compounds (VOCs) observed in the troposphere. Here a new experimental method is reported for the simultaneous study of reactions between multiple different VOCs and OH, the most important daytime atmospheric radical oxidant. This technique is based upon established relative rate concepts but has the advantage of a much higher throughput of target VOCs. By evaluating multiple VOCs in each experiment, and through measurement of the depletion in each VOC after reaction with OH, the OH + VOC reaction rate coefficients can be derived. Results from experiments conducted under controlled laboratory conditions were in good agreement with the available literature for the reaction of nineteen VOCs, prepared in synthetic gas mixtures, with OH. This approach was used to determine a rate coefficient for the reaction of OH with 2,3-dimethylpent-1-ene for the first time; k = 5.7 (±0.3) × 10–11–cm3 molecule−1 s−1. In addition, a further seven VOCs had only two, or fewer, individual OH rate coefficient measurements available in the literature. The results from this work were in good agreement with those measurements. A similar dataset, at an elevated temperature of 323 (±10) K, was used to determine new OH rate coefficients for twelve aromatic, five alkane, five alkene and three monoterpene VOC + OH reactions. In OH relative reactivity experiments that used ambient air at the University of York, a large number of different VOCs were observed, of which 23 were positively identified. 19 OH rate coefficients were derived from these ambient air samples, including ten reactions for which data was previously unavailable at the elevated reaction temperature of T = 323 (±10) K.


2018 ◽  
Vol 20 (8) ◽  
pp. 5865-5873 ◽  
Author(s):  
A. J. Ocaña ◽  
S. Blázquez ◽  
B. Ballesteros ◽  
A. Canosa ◽  
M. Antiñolo ◽  
...  

Rate coefficients for the OH-reaction with ethanol, ubiquitous in the interstellar medium, has been determined at ultra-cold temperatures by using the pulsed and continuous CRESU technique.


2016 ◽  
Vol 119 (1) ◽  
pp. 5-18
Author(s):  
Ádám Illés ◽  
Mária Farkas ◽  
Gábor László Zügner ◽  
Gyula Novodárszki ◽  
Magdolna Mihályi ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 51834-51844
Author(s):  
María B. Blanco ◽  
Ian Barnes ◽  
Peter Wiesen ◽  
Mariano A. Teruel

Rate coefficients as a function of temperature and product distribution studies have been performed for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique.


2012 ◽  
Vol 14 (18) ◽  
pp. 6596 ◽  
Author(s):  
Mohamed Ghalaieny ◽  
Asan Bacak ◽  
Max McGillen ◽  
Damien Martin ◽  
Alan V. Knights ◽  
...  

2006 ◽  
Vol 84 (12) ◽  
pp. 1686-1695 ◽  
Author(s):  
Anisha Garib ◽  
Qadir K Timerghazin ◽  
Parisa A Ariya

Halogens are suggested as important atmospheric oxidants in the marine boundary layer. The room-temperature kinetics of the chlorine-initiated reactions of three biogenic brominated hydrocarbons and four anthropogenic chlorinated ethenes was investigated by gas chromatography with flame ionization detection (GC–FID) at a pressure of 1 atm (1 atm = 101.325 kPa) in air, using the relative rate technique. The rate constants (× 1013 cm3 molecule–1 s–1) for CH2Br2, CHBr2Cl, and CHBr3 reactions at 298 ± 2 K were found to be 4.25 ± 0.65, 2.03 ± 0.31, and 2.81 ± 0.41, respectively, using methane as a reference compound. Room temperature rate constants (±1011 cm3 molecule–1 s–1) obtained for 1,1-dichloroethene, cis-dichloroethene, trans-dichloroethene, and trichloroethene using ethene as a reference are 13.4 ± 3.3, 9.1 ± 2.3, 7.4 ± 1.8, and 7.7 ± 1.9, respectively. The rate constants of chlorine-atom reactions with various hydrocarbons obtained in this work and taken from literature were correlated with corresponding rate constants of the OH radical available in the literature. The temperature dependences for the reactions of chlorine atoms with chlorinated ethenes were studied within the 298–358 K range. The corresponding Arrhenius expressions for the rate constants are (cm3 molecule–1 s–1): ln k = (–25.26 ± 0.17) – (758 ± 55)/T for 1,1-dichloroethene, ln k = (–25.79 ± 0.10) – (799 ± 34)/T for cis-dichloroethene, ln k = (–26.74 ± 0.09) – (1018 ± 28)/T for trans-dichloroethene, and ln k = (–26.10 ± 0.26) – (846 ± 83)/T for trichloroethene. In addition, product studies for the chlorine-initiated gas phase oxidation reactions of CHBr3 and CHBr2Cl were performed using gas chromatography with mass spectrometric detection (GC–MS). The only identified product for the reaction of CHBr3 with Cl reaction was COBr2, while for the CHBr2Cl + Cl reaction, COBrCl and COCl2 were observed, indicating the possibility of halogen atom release. The atmospheric implications of the results obtained are discussed.Key words: tropospheric reactions, kinetics, chlorine atoms, chlorinated hydrocarbons, brominated hydrocarbons.


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