Gas-phase rate coefficients of the reaction of ozone with four sesquiterpenes at 295 ± 2 K

2015 ◽  
Vol 17 (17) ◽  
pp. 11658-11669 ◽  
Author(s):  
Stefanie Richters ◽  
Hartmut Herrmann ◽  
Torsten Berndt
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Relative Rate ◽  
Rate Coefficients ◽  
Temperature Rate

Room temperature rate coefficients of the reaction of ozone with four sesquiterpenes were measured using absolute and relative rate techniques.

scholarly journals Direct and relative rate coefficients for the gas-phase reaction of OH radicals with 2-methyltetrahydrofuran at room temperature

2016 ◽  
Vol 119 (1) ◽  
pp. 5-18
Author(s):  
Ádám Illés ◽  
Mária Farkas ◽  
Gábor László Zügner ◽  
Gyula Novodárszki ◽  
Magdolna Mihályi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Relative Rate ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Relative Rate Coefficients

Direct Kinetic Study of Reactions of Hydroxyl Radicals with Alkyl Formates

2004 ◽  
Vol 218 (4) ◽  
pp. 479-492 ◽  
Author(s):  
István Szilágyi ◽  
Sándor Dóbé ◽  
Tibor Bérces ◽  
Ferenc Márta ◽  
Béla Viskolcz
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Room Temperature ◽  
Methyl Formate ◽  
Ethyl Formate ◽  
Rate Coefficients ◽  
Resonance Fluorescence ◽  
Gas Phase Reactions ◽  
Temperature Rate ◽  
Fast Flow

AbstractRate coefficients were determined for the gas phase reactions of hydroxyl radicals with a series of alkyl formats. Experiments were carried out using the isothermal fast flow method coupled with resonance fluorescence detection. The obtained room temperature rate coefficients are (in 10−13cm3 molecule−1s−1 units): 1.83 ± 0.33 (methyl formate), 9.65 ± 0.43 (ethyl formate), 18.73 ± 0.83 (isopropyl formate), 6.77 ± 0.38 (tert-butyl formate) and 1.62 ± 0.13 (methyl chloroformate). These results are compared with the literature data. In addition estimations are made for the partial reactivities of the formate group and for the hydrocarbon groups adjacent to HC(O)O. Moreover, it has been found that the partial reactivity of the HC(O)O group (in reactions of OH with formates) is two orders of magnitude smaller than that of the HC(O) group (in reactions of OH with aldehydes). This has been explained using the results of ab initio calculations at the G3MP2//MP2(full)/6-31G(d) level of theory.

scholarly journals Experimental and computational kinetics investigations for the reactions of Cl atoms with series of unsaturated ketones in gas phase

2017 ◽  
Author(s):  
Siripina Vijayakumar ◽  
Avinash Kumar ◽  
Balla Rajakuma
Keyword(s):  
Gas Phase ◽  
State Theory ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Unsaturated Ketones ◽  
Temperature Range ◽  
Computational Calculations ◽  
Temperature Rate ◽  
Cl Atoms

Abstract. Temperature dependent rate coefficients for the gas phase reactions of Cl atoms with 4-hexen-3-one and 5-hexen-2-one were measured over the temperature range of 298–363 K relative to 1-pentene, 1,3-butadiene and isoprene. Gas Chromatography (GC) was used to measure the concentrations of the organics. The derived temperature dependent Arrhenius expressions are k4-hexen-3-one+Cl (298–363 K) = (2.82 ± 1.76)×10−12exp [(1556 ± 438)/T] cm3 molecule−1 s−1 and k5-hexen-2-one+Cl (298–363 K) = (4.6 ± 2.4)×10−11exp[(646 ± 171)/T] cm3 molecule−1 s−1. The corresponding room temperature rate coefficients are (5.54 ± 0.41)×10−10 cm3 molecule−1 s−1 and (4.00 ± 0.37)×10−10 cm3 molecule−1 s−1 for the reactions of Cl atoms with 4-hexen-3-one and 5-hexen-2-one respectively. To understand the mechanism of Cl atom reactions with unsaturated ketones, computational calculations were performed for the reactions of Cl atoms with 4-hexen-3-one, 5-hexen-2-one and 3-penten-2-one over the temperature range of 275–400 K using Canonical Variational Transition state theory (CVT) with Small Curvature Tunneling (SCT) in combination with CCSD(T)/6-31+G(d, p)//MP2/6-311++G(d, p) level of theory. Atmospheric implications, reaction mechanism and feasibility of the title reactions are discussed in this manuscript.

Gas-phase rate coefficients for the reactions of nitrate radicals with (Z)-pent-2-ene, (E)-pent-2-ene, (Z)-hex-2-ene, (E)-hex-2-ene, (Z)-hex-3-ene, (E)-hex-3-ene and (E)-3-methylpent-2-ene at room temperature

2005 ◽  
Vol 7 (12) ◽  
pp. 2506 ◽  
Author(s):  
Christian Pfrang ◽  
Robert S. MartinPresent address: University o ◽  
Andrew Nalty ◽  
Richard Waring ◽  
Carlos E. Canosa-Mas ◽  
...  
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Rate Coefficients ◽  
Nitrate Radicals

Determination of gas-phase ozonolysis rate coefficients of a number of sesquiterpenes at elevated temperatures using the relative rate method

2012 ◽  
Vol 14 (18) ◽  
pp. 6596 ◽  
Author(s):  
Mohamed Ghalaieny ◽  
Asan Bacak ◽  
Max McGillen ◽  
Damien Martin ◽  
Alan V. Knights ◽  
...  
Keyword(s):  
Gas Phase ◽  
Elevated Temperatures ◽  
Relative Rate ◽  
Rate Coefficients ◽  
Rate Method

scholarly journals The atmospheric chemistry of sulphuryl fluoride, SO<sub>2</sub>F<sub>2</sub>

2008 ◽  
Vol 8 (6) ◽  
pp. 1547-1557 ◽  
Author(s):  
T. J. Dillon ◽  
A. Horowitz ◽  
J. N. Crowley
Keyword(s):  
Atmospheric Chemistry ◽  
Rate Coefficient ◽  
Relative Rate ◽  
Significant Loss ◽  
Rate Coefficients ◽  
Atmospheric Species ◽  
Upper Limits ◽  
Wall Flow ◽  
Temperature Rate ◽  
Good Agreement

Abstract. The atmospheric chemistry of sulphuryl fluoride, SO2F2, was investigated in a series of laboratory studies. A competitive rate method, using pulsed laser photolysis (PLP) to generate O(1D) coupled to detection of OH by laser induced fluorescence (LIF), was used to determine the overall rate coefficient for the reaction O(1D) + SO2F2 → products (R1) of k1 (220–300 K) = (1.3 ± 0.2) × 10−10 cm3 molecule−1 s−1. Monitoring the O(3P) product (R1a) enabled the contribution (α) of the physical quenching process (in which SO2F2 is not consumed) to be determined as α (225–296 K)=(0.55 ± 0.04). Separate, relative rate measurements at 298 K provided a rate coefficient for reactive loss of O(1D), k1b, of (5.8 ± 0.8) × 10−11 cm3 molecule−1 s−1 in good agreement with the value calculated from (1−α) × k1=(5.9 ± 1.0) × 10−11 cm3 molecule−1 s−1. Upper limits for the rate coefficients for reaction of SO2F2 with OH (R2, using PLP-LIF), and with O3 (R3, static reactor) were determined as k2 (294 K)<1 × 10−15 cm3 molecule−1 s−1 and k3 (294 K)<1 × 10−23 cm3 molecule−1 s−1. In experiments using the wetted-wall flow tube technique, no loss of SO2F2 onto aqueous surfaces was observed, allowing an upper limit for the uptake coefficient of γ(pH 2–12)<1 × 10−7 to be determined. These results indicate that SO2F2 has no significant loss processes in the troposphere, and a very long stratospheric lifetime. Integrated band intensities for SO2F2 infrared absorption features between 6 and 19 μm were obtained, and indicate a significant global warming potential for this molecule. In the course of this work, ambient temperature rate coefficients for the reactions O(1D) with several important atmospheric species were determined. The results (in units of 10−10 cm3 molecule−1 s−1, k(O1D + N2)=(0.33 ± 0.06); k(O1D + N2O)=(1.47 ± 0.2) and k(O1D + H2O)=(1.94 ± 0.5) were in good agreement with other recent determinations.

scholarly journals A self-consistent, multivariate method for the determination of gas-phase rate coefficients, applied to reactions of atmospheric VOCs and the hydroxyl radical

2018 ◽  
Vol 18 (6) ◽  
pp. 4039-4054 ◽  
Author(s):  
Jacob T. Shaw ◽  
Richard T. Lidster ◽  
Danny R. Cryer ◽  
Noelia Ramirez ◽  
Fiona C. Whiting ◽  
...  
Keyword(s):  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Rate Coefficient ◽  
Relative Rate ◽  
Ambient Air ◽  
Rate Coefficients ◽  
Oxidation Reactions ◽  
Simultaneous Study ◽  
The University ◽  
Good Agreement

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.

scholarly journals A self-consistent, multi-variate method for the determination of gas phase rate coefficients, applied to reactions of atmospheric VOCs and the hydroxyl radical

2017 ◽  
Author(s):  
Jacob T. Shaw ◽  
Richard T. Lidster ◽  
Danny R. Cryer ◽  
Noelia Ramirez ◽  
Graham A. Boustead ◽  
...  
Keyword(s):  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Rate Coefficient ◽  
Relative Rate ◽  
Ambient Air ◽  
Rate Coefficients ◽  
Oxidation Reactions ◽  
Oh Reactions ◽  
Simultaneous Study ◽  
Good Agreement

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 (&amp;pm;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.

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