Reaction between OH and HCHO: temperature dependent rate coefficients (202–399 K) and product pathways (298 K)

Sivakumaran, V.; Hölscher, Dirk; Dillon, Terry J.; Crowley, John N.

doi:10.1039/b306859e

Cited by 48 publications

(60 citation statements)

References 40 publications

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“…Also shown are data from experimental and theoretical studies. 23,24,25,26,27,28,29,30,31 The rate constant computed using CC-a//BH-a exhibits a very weak pressure-dependence, consistent with previous studies, 23,24,25 and a distinct negative temperature-dependence. However, rate constants computed using CC-a//CC-a exhibit a weakly positive temperature-dependence.…”

Section: Oh + Ch2o Reaction Systemsupporting

confidence: 82%

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Ali

Barker

2015

J. Phys. Chem. A

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Methylenimine (CH2NH) has been predicted to be a product of the atmospheric photo-oxidation of methylamine, but its atmospheric reactions have not been measured. In this paper, we report potential energy surfaces (PESs) and rate constants for OH + CH2NH and its isoelectronic analogues OH + CH2O and OH + CH2CH2, which are more fully understood. The PESs were computed using the BHandHLYP/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels of theory. Canonical variational transition state theory and Rice-Ramsperger-Kassel-Marcus and master equation modeling were used to calculate temperature- and pressure-dependent rate constants, with particular emphasis on the OH + reactant entrance channels and the effects of prereactive complexes. The computed results are in reasonable agreement with experimental data where they can be compared and also with the results of previous theoretical calculations. The results show that to some extent OH radicals both add to the carbon center double bond in CH2NH and abstract methylene hydrogen atoms, as in the OH + CH2O and OH + CH2CH2 reactions, respectively, but the dominant pathway is abstraction of the hydrogen from N-H. The computed rate constants are suitable for both atmospheric and combustion modeling.

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Section: Oh + Ch2o Reaction Systemsupporting

confidence: 82%

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Ali

Barker

2015

J. Phys. Chem. A

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“…where T is in K. Equation (II) not only reconciles the most recent low-temperature data on reaction (2) [33,38] with our high-temperature experiments, but also fits reasonably well (to within 15%) some of the available experimental data [34,41] at intermediate temperatures (400-600 K).…”

Section: Ch 2 O + Oh = Hco + H 2 O: Comparison With Earlier Worksupporting

confidence: 77%

“…The use of tert-butyl hydroperoxide as an OH precursor, in conjunction with the sensitive detection of OH using narrow-linewidth ring dye laser absorption, facilitated accurate, direct measurements of this reaction over a wide range of temperatures (934-1670 K). Detailed error analyses, taking into account both experimental and mechanisminduced contributions, yielded uncertainty estimates of ±25% at 1595 K and ±15% at 1229 K. These hightemperature measurements were fit with the low temperature data of Sivakumaran et al [33], and the following rate expression, applicable over the temperature range 200-1670 K, was obtained k 2 = 7.82 × 10 7 T 1.63 exp(531/T )(cm 3 mol…”

Section: Discussionmentioning

confidence: 99%

“…The interest in this reaction at low temperatures stems from the critical role that CH 2 O plays in atmospheric chemistry. The reaction of CH 2 O with OH is one of the major atmospheric sinks of CH 2 O, especially in the lower troposphere [33]. The most recent low-temperature measurements of this reaction are those by Sivakumaran et al [33], where pulsed laser photolytic generation of OH radicals coupled with detection by pulsed LIF was employed to measure absolute rate coefficients for reaction (2) over the temperature range 202-399 K. The JPL 2004 evaluation [38] for this rate, which takes into account several low-temperature studies [32][33][34][35]37] …”

Section: Ch 2 O + Oh = Hco + H 2 O: Comparison With Earlier Workmentioning

confidence: 99%

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Direct measurements of the reaction OH + CH₂O → HCO + H₂O at high temperatures

Vasudevan

Davidson

Hanson

2004

Int J of Chemical Kinetics

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The reaction of hydroxyl [OH] radicals with formaldehyde [CH 2 O] was studied at temperatures ranging from 934 K to 1670 K behind reflected shock waves at an average total pressure of 1.6 atm. OH radicals were produced by shock-heating tert-butyl hydroperoxide [(CH 3 ) 3 CO OH], while 1,3,5-trioxane [(CH 2 O) 3 ] was used in the preshock mixtures to generate reproducible levels of CH 2 O. OH concentration time-histories were inferred from laser absorption using the well-characterized R 1 (5) line of the OH A-X (0, 0) band near 306.7 nm. Detailed error analyses, taking into account both experimental and mechanism-induced contributions, yielded uncertainty estimates of ±25% at 1595 K and ±15% at 1229 K for the rate of the reaction between CH 2 O and OH. These uncertainties are substantially lower than the factor of two uncertainty currently used for this reaction at high temperatures. The rate constants were fit with the recent low-temperature measurements of Sivakumaran et al. (Phys Chem Chem Phys 2003,5,4821-4827) to the three-parameter form shown below; this fit reconciles experimental data on the title reaction at low, intermediate, and high temperatures (200-1670 K).The reaction of OH with CH 2 O was also studied using quantum chemical methods at the CCSD(T) level of theory using the 6-311++G(d,p) basis set. The transition state for the H-atom metathesis reaction was located, and reaction rate coefficients were calculated. Reasonable agreement with the experimental measurements was obtained.

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“…[22] Attenuation of radiation (260 < l/nm < 560 nm) in a l = 892 cm multipass cell, connected serially upstream of the reaction cell [23] …”

Section: Methodsmentioning

confidence: 99%

Rate Coefficients for the Reaction of Iodine Oxide with Methyl Peroxy Radicals

2010

Self Cite

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Pulsed laser photolysis radical generation is used to study the title reaction IO+CH(3)O(2)→products. Sensitive and selective laser-induced fluorescence detection of IO allows excess CH(3)O(2) conditions to be maintained throughout, ensuring minimal interference from other fast IO reactions. The rate coefficients, k(5)(296 K)=(3.4±1.4)×10(-12) cm(3) molecule(-1) s(-1), are obtained relative to a well-characterised reference value (k(3) for IO+HO(2)). This result agrees well with a previous determination from this laboratory and demonstrates that the above reaction proceeds an order of magnitude slower than suggested in other recent experimental and theoretical studies. Implications for HOx production/O(3) destruction within the marine boundary layer are briefly discussed.

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Reaction between OH and HCHO: temperature dependent rate coefficients (202–399 K) and product pathways (298 K)

Cited by 48 publications

References 40 publications

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Direct measurements of the reaction OH + CH₂O → HCO + H₂O at high temperatures

Rate Coefficients for the Reaction of Iodine Oxide with Methyl Peroxy Radicals

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Reaction between OH and HCHO: temperature dependent rate coefficients (202–399 K) and product pathways (298 K)

Cited by 48 publications

References 40 publications

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH2O, OH + CH2CH2, and OH + CH2NH

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH2O, OH + CH2CH2, and OH + CH2NH

Direct measurements of the reaction OH + CH2O → HCO + H2O at high temperatures

Rate Coefficients for the Reaction of Iodine Oxide with Methyl Peroxy Radicals

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Product

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Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Comparison of Three Isoelectronic Multiple-Well Reaction Systems: OH + CH₂O, OH + CH₂CH₂, and OH + CH₂NH

Direct measurements of the reaction OH + CH₂O → HCO + H₂O at high temperatures