Laser spectrometry and kinetics of selected elementary reactions of the acetonyl radical

Imrik, K.; Farkas, Edit; Vasvári, Gábor; Szilágyi, István; Sarzyński, Dariusz; Dóbé, Sándor; Bérces, T.; Márta, F.

doi:10.1039/b404889j

Cited by 19 publications

(38 citation statements)

References 52 publications

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“…The applied DF-LIF technique has recently been described in detail [2] and hence only a brief summary is given here.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…The radical site in acetonyl is partially delocalized over the carbonyl double bond, which has been found to give rise to unusual kinetic behavior in some of the elementary reactions of this free radical [2,3]. As a continuation of our previous experimental and theoretical work [2][3][4] on the structurereactivity relations of acetonyl, we have studied the reaction of CH 3 C(O)CH 2 radical with Br 2 molecule (1). This reaction has relevance also for the enthalpy of formation of the acetonyl radical: in the classical photobromination study of acetone by King et al [5], reaction (1) was assumed to have small positive activation energy at deriving ∆ f H°2 98 (CH 3 C(O)CH 2 ), but no method was available at the time of the investigations to confirm the assumption of the authors.…”

Section: Introductionmentioning

confidence: 99%

“…Acetonyl (1-methylvinoxyl) radical, CH 3 C(O)CH 2 , plays an important role in the chemistry of the troposphere affecting HOx and NOx cycles and in this way tropospheric O 3 budget.…”

Section: Introductionmentioning

confidence: 99%

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Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Zügner

Szabó

et al. 2013

Chemical Physics Letters

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The low pressure fast discharge flow method with laser induced fluorescence detection of CH 3 C(O)CH 2 was employed to study the kinetics of the reaction CH 3 C(O)CH 2 + Br 2 → CH 3 C(O)CH 2 Br + Br (1) at 298, 323 and 365 K. The rate coefficient at room temperature is k 1 = (2.33 ± 0.04 (2σ)) × 10 -12 cm 3 molecule -1 s -1 , which increases slightly with increasing temperature. Quantum chemistry (G2) and theoretical rate theory (conventional TST) computations have supplied results in qualitative agreement with experiment. The relatively slow rate of reaction (1) can be due to the resonance stabilization of the acetonyl radical.

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“…The applied DF-LIF technique has recently been described in detail [2] and hence only a brief summary is given here.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Acetonyl (1-methylvinoxyl) radical, CH 3 C(O)CH 2 , plays an important role in the chemistry of the troposphere affecting HOx and NOx cycles and in this way tropospheric O 3 budget.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Zügner

Szabó

et al. 2013

Chemical Physics Letters

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“…The low pressure fast discharge flow method (DF) coupled with resonance fluorescence detection of OH radicals (RF) was applied to study the kinetics of the reactions of OH with C 2 H 5 F and CH 3 C(O)F. The apparatus and experimental procedure have been described in detail previously 27,28 and so only a brief summary is presented here.…”

Section: Discharge Flow Techniquementioning

confidence: 99%

Experimental and Theoretical Study on the OH-Reaction Kinetics and Photochemistry of Acetyl Fluoride (CH₃C(O)F), an Atmospheric Degradation Intermediate of HFC-161 (C₂H₅F)

Song

Zügner

et al. 2015

J. Phys. Chem. A

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ABSTRACT:The direct reaction kinetic method of low pressure fast discharge flow (DF) with resonance fluorescence monitoring of OH (RF) has been applied to determine rate coefficients for the overall reactions OH + C 2 H 5 F (EtF) (1) and OH + CH 3 C(O)F (AcF) (2). Acetyl fluoride reacts slowly with the hydroxyl radical, the rate coefficient at laboratory temperature is k2 (300 K) = (0.74 ± 0.05) × 10 -14 cm 3 molecule -1 s -1 (given with 2σ statistical uncertainty). The temperature dependence of the reaction does not obey the Arrhenius law and it is described well by the two-exponential rate expression of k 2 (300-410 K) = 3.60 × 10 -3 exp(-10500 / T) + 1.56 × 10 -13 exp(-910 / T) cm 3 molecule -1 s -1 . The rate coefficient of k 1 = (1.90 ± 0.19) × 10 -13 cm 3 molecule -1 s -1 has been determined for the EtF-reaction at room temperature (T = 298 K).Microscopic mechanisms for the OH + CH 3 C(O)F reaction have also been studied theoretically using the ab initio CBS-QB3 an G4 methods. Variational transition state theory was employed to obtain rate coefficients for the OH + CH 3 C(O)F reaction as a function of temperature on the basis of the ab initio data. The calculated rate coefficients are in good agreement with the experimental data. It is revealed that the reaction takes place predominantly via the indirect H-abstraction mechanism involving H-bonded prereactive complexes and forming the nascent products of H 2 O and the CH 2 CFO radical. The nonArrhenius behavior of the rate coefficient at temperatures below 500 K is ascribed to the significant tunneling effect of the in-the-plane H-abstraction dynamic bottleneck. The production of FC(O)OH + CH 3 via the addition/elimination mechanism is hardly competitive due to the significant barriers along the reaction routes.Photochemical experiments of AcF were performed at 248 nm by using exciplex lasers. The total photodissociation quantum yield for CH 3 C(O)F has been found significantly less than unity; among the primary photochemical processes, C-C bond cleavage is by far dominating compared with CO-elimination. The absorption spectrum of AcF has also been determined displaying a strong blue shift compared with the spectra of aliphatic carbonyls.Consequences of the results on atmospheric chemistry have been discussed.3

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Rate constant for the reaction of CH₃C(O)CH₂ radical with HBr and its thermochemical implication

Farkas

Kovács

Szilágyi

et al. 2005

Int J of Chemical Kinetics

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The fast flow method with laser induced fluorescence detection of CH 3 C(O)CH 2 was employed to obtain the rate constant of k 1 (298 K) = (1.83 ± 0.12 (1σ)) × 10 10 cm 3 mol −1 s −1 for the reaction CH 3 C(O)CH 2 + HBr ↔ CH 3 C(O)CH 3 + Br (1, −1). The observed reduced reactivity compared with n-alkyl or alkoxyl radicals can be attributed to the partial resonance stabilization of the acetonyl radical. An application of k 1 in a third law estimation provides

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Laser spectrometry and kinetics of selected elementary reactions of the acetonyl radical

Cited by 19 publications

References 52 publications

Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Experimental and Theoretical Study on the OH-Reaction Kinetics and Photochemistry of Acetyl Fluoride (CH₃C(O)F), an Atmospheric Degradation Intermediate of HFC-161 (C₂H₅F)

Rate constant for the reaction of CH₃C(O)CH₂ radical with HBr and its thermochemical implication

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Laser spectrometry and kinetics of selected elementary reactions of the acetonyl radical

Cited by 19 publications

References 52 publications

Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Kinetics and mechanism of the reaction of acetonyl radical, CH3C(O)CH2, with Br2

Experimental and Theoretical Study on the OH-Reaction Kinetics and Photochemistry of Acetyl Fluoride (CH3C(O)F), an Atmospheric Degradation Intermediate of HFC-161 (C2H5F)

Rate constant for the reaction of CH3C(O)CH2 radical with HBr and its thermochemical implication

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Product

Resources

About

Experimental and Theoretical Study on the OH-Reaction Kinetics and Photochemistry of Acetyl Fluoride (CH₃C(O)F), an Atmospheric Degradation Intermediate of HFC-161 (C₂H₅F)

Rate constant for the reaction of CH₃C(O)CH₂ radical with HBr and its thermochemical implication