scholarly journals Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (<i>E</i>)-4-methoxy-3-buten-2-one and 1-(<i>E</i>)-1-methoxy-2-methyl-1-penten-3-one

2020 ◽  
Author(s):  
Rodrigo Gastón Gibilisco ◽  
Ian Barnes ◽  
Iustinian Gabriel Bejan ◽  
Peter Wiesen
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Oxidation Products ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Ozone Formation Potential ◽  
Nitrogen Containing Compounds ◽  
First Time

Abstract. The kinetics of the gas-phase reactions of hydroxyl radicals with two unsaturated methoxy-ketones at (298 ± 3) K and 1 atm of synthetic air have been studied for the first time using the relative rate technique in an environmental reaction chamber by in situ FTIR spectrometry. The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10–10 cm3 molecule−1 s−1) as follows: k1(OH + (E)-4-methoxy-3-buten-2-one) = (1.42 ± 0.12), and k2(OH + 1-(E)-1-methoxy-2-methyl-1-penten-3-one) = (3.34 ± 0.43). In addition, quantification of the main oxidation products has been performed and degradation mechanisms for these reactions were developed. The formation products and kinetic data confirm that the reactions proceed mainly via an addition of the OH radical to the double bond. Gas phase products, identified and quantified from these reactions, are carbonyls like methyl formate, methyl glyoxal and 2,3-pentanedione and long-lived nitrogen containing compounds such as PAN and PPN. Atmospheric lifetimes and the ozone formation potential have been estimated and possible atmospheric implications assessed.

scholarly journals Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (<i>E</i>)-4-methoxy-3-buten-2-one and (1<i>E</i>)-1-methoxy-2-methyl-1-penten-3-one

2020 ◽  
Vol 20 (14) ◽  
pp. 8939-8951
Author(s):  
Rodrigo Gastón Gibilisco ◽  
Ian Barnes ◽  
Iustinian Gabriel Bejan ◽  
Peter Wiesen
Keyword(s):  
Hydroxyl Radicals ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Oxidation Products ◽  
Rate Coefficients ◽  
Main Reaction ◽  
Reaction Products ◽  
Gas Phase Reactions ◽  
Nitrogen Containing Compounds ◽  
First Time

Abstract. The kinetics of the gas phase reactions of hydroxyl radicals with two unsaturated ketoethers (UKEs) at (298±3) K and 1 atm of synthetic air have been studied for the first time using the relative-rate technique in an environmental reaction chamber by in situ Fourier-transform infrared spectroscopy (FTIR). The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10−10 cm3 molecule−1 s−1) as follows: kTMBO (OH + (E)-4-methoxy-3-buten-2-one)  =  (1.41±0.11) and kMMPO (OH + (1E)-1-methoxy-2-methyl-1-penten-3-one)  =  (3.34±0.43). In addition, quantification of the main oxidation products in the presence of NOx has been performed, and degradation mechanisms for these reactions were developed. Methyl formate, methyl glyoxal, peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were identified as main reaction products and quantified for both reactions. The results of the present study provide new insights regarding the contribution of these multifunctional volatile organic compounds (VOCs) in the generation of secondary organic aerosols (SOAs) and long-lived nitrogen containing compounds in the atmosphere. Atmospheric lifetimes and implications are discussed in light of the obtained results.

scholarly journals Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 51834-51844
Author(s):  
María B. Blanco ◽  
Ian Barnes ◽  
Peter Wiesen ◽  
Mariano A. Teruel
Keyword(s):  
Relative Rate ◽  
Product Distribution ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Dependent Rate ◽  
P Rate ◽  
Distribution Studies ◽  
First Time ◽  
Cl Atoms

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.

Rate Coefficients for the Gas-Phase Reactions of Hydroxyl Radicals with a Series of Methoxylated Aromatic Compounds

2015 ◽  
Vol 119 (24) ◽  
pp. 6179-6187 ◽  
Author(s):  
Amélie Lauraguais ◽  
Iustinian Bejan ◽  
Ian Barnes ◽  
Peter Wiesen ◽  
Cécile Coeur
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Aromatic Compounds ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Methoxylated Aromatic

scholarly journals Degradation of a series of fluorinated acrylates and methacrylates initiated by OH radicals at different temperatures

RSC Advances ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 4264-4273
Author(s):  
P. Lugo García ◽  
C. B. Rivela ◽  
R. G. Gibilisco ◽  
S. Salgado ◽  
P. Wiesen ◽  
...  
Keyword(s):  
Gas Phase ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Gas Phase Reactions ◽  
P Rate ◽  
Different Temperatures ◽  
First Time ◽  
Fluorinated Acrylates

Rate coefficients for the gas-phase reactions of OH radicals with a series of fluorinated acrylates and methacrylates have been measured for the first time as a function of temperature in the range 290–308 K.

scholarly journals NO<sub>3</sub> chemistry of wildfire emissions: a kinetic study of the gas-phase reactions of furans with the NO<sub>3</sub> radical

2021 ◽  
Author(s):  
Mike J. Newland ◽  
Yangang Ren ◽  
Max R. McGillen ◽  
Lisa Michelat ◽  
Véronique Daële ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Reaction Rate ◽  
Relative Rate ◽  
Rate Coefficients ◽  
Nitrate Radical ◽  
Gas Phase Reactions ◽  
Removal Process ◽  
Order Of Magnitude ◽  
First Time ◽  
Substituted Furans

Abstract. Furans are emitted to the atmosphere during biomass burning from the pyrolysis of cellulose. They are one of the major contributing VOC classes to OH and NO3 reactivity in biomass burning plumes. The major removal process of furans from the atmosphere at night is reaction with the nitrate radical, NO3. Here we report a series of relative rate experiments in the 7300 L indoor simulation chamber at CNRS-ICARE, Orléans, using a number of different reference compounds to determine NO3 reaction rate coefficients for four furans, two furanones, and pyrrole. In the case of the two furanones, this is the first time that NO3 rate coefficients have been reported. The recommended values (cm3 molecule−1 s−1) are: furan (1.50 ± 0.23) × 10−12, 2-methylfuran (2.37 ± 0.55) × 10−11, 2,5-dimethylfuran (1.10 ± 0.33) × 10−10, furan-2-aldehyde (9.28 ± 2.3) × 10−14, 5-methyl-2(3H)-furanone (3.00 ± 0.45) × 10−12, 2(5H)-furanone < 1.410−16, and pyrrole (7.35 ± 2.06) × 10−11. The furan-2-aldehyde + NO3 reaction rate is found to be an order of magnitude lower than previously reported. We also recommend a faster rate for the α-terpinene+NO3 reaction ((2.70 ± 0.81) × 10−10 cm3 s−1). These experiments show that for furan, alkyl substituted furans, 5-methyl-2(3H)-furanone, and pyrrole, reaction with NO3 will be the dominant removal process at night, and may also contribute during the day. For 2(5H)-furanone, reaction with NO3 is not an important atmospheric sink.

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.

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