Gas-phase reactivity of CH3C(O) CH3 with OH radicals at interstellar Temperatures (T = 11.7 – 64.4 K) using the CRESU technique

2019 ◽  
Vol 15 (S350) ◽  
pp. 379-381
Author(s):  
Sergio Blázquez ◽  
Antonio J. Ocaña ◽  
Alberto García ◽  
Bernabé Ballesteros ◽  
André Canosa ◽  
...  
Keyword(s):  
Supersonic Flow ◽  
Low Temperature ◽  
Gas Phase ◽  
Pressure Dependence ◽  
Freezing Point ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Condensation ◽  
Gas Phase Reaction

AbstractThe rate coefficients, k(T= 11.7 – 64.4 K), for the gas-phase reaction between OH radicals and acetone, CH3C(O) CH3, have been measured using the pulsed CRESU (French acronym for Reaction Kinetics in a Uniform Supersonic Flow) technique, the most suitable one to cool down gases below the freezing point without gas condensation. The experimental k(T) was found to increase as temperature was lowered and is several orders of magnitude higher for low temperature than k(300 K). No pressure dependence of k(20 K) and k(64 K) was observed, while k(50 K) at the largest gas density is twice higher than the average values found at lower gas densities. The obtained values of k(11.7 K) and k(21.1 K) were 2.45’10-10 and 1.39’10-10 cm3 molecule-1 s-1, respectively.

Rate coefficients for the gas-phase reaction of OH radicals with dimethyl sulfide: temperature and O2partial pressure dependence

2006 ◽  
Vol 8 (6) ◽  
pp. 728-736 ◽  
Author(s):  
Mihaela Albu ◽  
Ian Barnes ◽  
Karl H. Becker ◽  
Iulia Patroescu-Klotz ◽  
Raluca Mocanu ◽  
...  
Keyword(s):  
Gas Phase ◽  
Pressure Dependence ◽  
Dimethyl Sulfide ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Phase Reaction

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

scholarly journals Rate coefficients for the gas-phase reaction of OH with <i>Z</i>-3-hexen-1-ol, 1-penten-3-ol, <i>E</i>-2-penten-1-ol, and <i>E</i>-2-hexen-1-ol between 243 and 404 K

2011 ◽  
Vol 11 (1) ◽  
pp. 2377-2405 ◽  
Author(s):  
M. E. Davis ◽  
J. B. Burkholder
Keyword(s):  
Gas Phase ◽  
Negative Temperature ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Oh Radical ◽  
Gas Phase Reaction ◽  
First Order ◽  
Unsaturated Alcohols ◽  
Temperature Dependences

Abstract. Rate coefficients, k, for the gas-phase reaction of the OH radical with (Z)-3-hexen-1-ol ((Z)-CH3CH2CH=CHCH2CH2OH). (k1), 1-penten-3-ol (CH3CH2CH(OH)CH=CH2) (k2), (E)-2-penten-1-ol ((E)-CH3CH2CH=CHCH2OH) (k3), and (E)-2-hexen-1-ol ((E)-CH3CH2CH2CH=CHCH2OH) (k4), unsaturated alcohols that are emitted into the atmosphere following vegetation wounding, are reported. Rate coefficients were measured under pseudo-first-order conditions in OH over the temperature range 243–404 K at pressures between 20 and 100 Torr (He) using pulsed laser photolysis (PLP) to produce OH radicals and laser induced fluorescence (LIF) to monitor the OH temporal profile. The obtained rate coefficients were independent of pressure with negative temperature dependences that are well described by the Arrhenius expressions k1(T) = (1.3 ± 0.1) × 10−11 exp[(580 ± 10)/T]; k1(297K) = (1.06 ± 0.12) × 10−10 k2(T) = (6.8 ± 0.7) × 10−12 exp[(690 ± 20)/T]; k2(297K) = (7.12 ± 0.73) × 10−11 k3(T) = (6.8 ± 0.8) × 10−12 exp[(680 ± 20)/T]; k3(297K) = (6.76 ± 0.70) × 10−11 k4(T) = (5.4 ± 0.6) × 10−12 exp[(690 ± 20)/T]; k4(297K) = (6.15 ± 0.75) × 10−11 (in units of cm3 molecule−1 s−1). The quoted uncertainties are at the 2σ (95% confidence) level and include estimated systematic errors. The rate coefficients obtained in this study are compared with literature values where possible.

scholarly journals A low temperature investigation of the gas-phase N(2D) + NO reaction. Towards a viable source of N(2D) atoms for kinetic studies in astrochemistry

2018 ◽  
Vol 20 (25) ◽  
pp. 17442-17447 ◽  
Author(s):  
Dianailys Nuñez-Reyes ◽  
Kevin M. Hickson
Keyword(s):  
Nitric Oxide ◽  
Supersonic Flow ◽  
Low Temperature ◽  
Gas Phase ◽  
Flow Reactor ◽  
Kinetic Studies ◽  
Phase Reaction ◽  
Atomic Nitrogen ◽  
Gas Phase Reaction ◽  
Temperature Range

The gas-phase reaction of metastable atomic nitrogen N(2D) with nitric oxide has been investigated over the 296–50 K temperature range using a supersonic flow reactor.

scholarly journals Rate coefficients for the gas-phase reaction of OH with (<i>Z</i>)-3-hexen-1-ol, 1-penten-3-ol, (<i>E</i>)-2-penten-1-ol, and (<i>E</i>)-2-hexen-1-ol between 243 and 404 K

2011 ◽  
Vol 11 (7) ◽  
pp. 3347-3358 ◽  
Author(s):  
M. E. Davis ◽  
J. B. Burkholder
Keyword(s):  
Gas Phase ◽  
Negative Temperature ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Oh Radical ◽  
Gas Phase Reaction ◽  
First Order ◽  
Unsaturated Alcohols ◽  
Temperature Dependences

Abstract. Rate coefficients, k, for the gas-phase reaction of the OH radical with (Z)-3-hexen-1-ol (Z)-CH3CH2CH = CHCH2CH2OH) (k1), 1-penten-3-ol (CH3CH2CH(OH)CH = CH2) (k2), (E)-2-penten-1-ol ((E)-CH3CH2CH = CHCH2OH) (k3), and (E)-2-hexen-1-ol ((E)-CH3CH2CH2CH = CHCH2OH) (k4), unsaturated alcohols that are emitted into the atmosphere following vegetation wounding, are reported. Rate coefficients were measured under pseudo-first-order conditions in OH over the temperature range 243–404 K at pressures between 20 and 100 Torr (He) using pulsed laser photolysis (PLP) to produce OH radicals and laser induced fluorescence (LIF) to monitor the OH temporal profile. The obtained rate coefficients were independent of pressure with negative temperature dependences that are well described by the Arrhenius expressions k1(T) = (1.3 ± 0.1) × 10−11 exp[(580 ± 10)/T]; k1(297 K) = (1.06 ± 0.12) × 10−10 k2(T) = (6.8 ± 0.7) × 10−12 exp[(690 ± 20)/T]; k2(297 K) = (7.12 ± 0.73) × 10−11 k3(T) = (6.8 ± 0.8) × 10−12 exp[(680 ± 20)/T]; k3(297 K) = (6.76 ± 0.70) × 10−11 k4(T) = (5.4 − 0.6) × 10−12 exp[(690 ± 20)/T]; k4(297 K) = (6.15 ± 0.75) × 10−11 (in units of cm3 molecule−1 s−1). The quoted uncertainties are at the 2σ (95% confidence) level and include estimated systematic errors. The rate coefficients obtained in this study are compared with literature values where possible.

Effect of NOx on product yields and Arrhenius parameters of gas-phase oxidation of β-ocimene initiated by OH˙ radicals

RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 92795-92803 ◽  
Author(s):  
Elizabeth Gaona-Colmán ◽  
María B. Blanco ◽  
Ian Barnes ◽  
Mariano A. Teruel
Keyword(s):  
Gas Phase ◽  
Total Pressure ◽  
Addition Product ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Phase Oxidation ◽  
P Rate ◽  
Gas Phase Oxidation

Rate coefficients for the gas-phase reaction of OH˙ radicals with β-ocimene were measured over the temperature range 288–311 K at 760 Torr total pressure of nitrogen. In addition, product studies have been performed in the absence and presence of NOx.

scholarly journals Reactive quenching of electronically excited NO<sub>2</sub><sup>∗</sup> and NO<sub>3</sub><sup>∗</sup> by H<sub>2</sub>O as potential sources of atmospheric HO<sub><i>x</i></sub> radicals

2018 ◽  
Vol 18 (19) ◽  
pp. 14005-14015 ◽  
Author(s):  
Terry J. Dillon ◽  
John N. Crowley
Keyword(s):  
Gas Phase ◽  
Laser Excitation ◽  
Pulsed Laser ◽  
Work Rate ◽  
Rate Coefficients ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Upper Limit ◽  
Upper Limits ◽  
Electronically Excited

Abstract. Pulsed laser excitation of NO2 (532–647 nm) or NO3 (623–662 nm) in the presence of H2O was used to initiate the gas-phase reaction NO2∗+H2O → products (Reaction R5) and NO3∗+H2O → products (Reaction R12). No evidence for OH production in Reactions (R5) or (R12) was observed and upper limits for OH production of k5b/k5<1×10-5 and k12b/k12<0.03 were assigned. The upper limit for k5b∕k5 renders this reaction insignificant as a source of OH in the atmosphere and extends the studies (Crowley and Carl, 1997; Carr et al., 2009; Amedro et al., 2011) which demonstrate that the previously reported large OH yield by Li et al. (2008) was erroneous. The upper limit obtained for k12b∕k12 indicates that non-reactive energy transfer is the dominant mechanism for Reaction (R12), though generation of small but significant amounts of atmospheric HOx and HONO cannot be ruled out. In the course of this work, rate coefficients for overall removal of NO3∗ by N2 (Reaction R10) and by H2O (Reaction R12) were determined: k10=(2.1±0.1)×10-11 cm3 molecule−1 s−1 and k12=(1.6±0.3)×10-10 cm3 molecule−1 s−1. Our value of k12 is more than a factor of 4 smaller than the single previously reported value.

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