Gas Phase OH Radical Reaction with 2‐Chloroethyl Vinyl Ether in the 256–333 K Temperature Range: A Combined LP‐LIF and Computational Study

2018 ◽  
Vol 3 (21) ◽  
pp. 5910-5919
Author(s):  
Monali N. Kawade ◽  
Doddipatla Srinivas ◽  
Hari P. Upadhyaya
Keyword(s):  
Gas Phase ◽  
Vinyl Ether ◽  
Computational Study ◽  
Radical Reaction ◽  
Oh Radical ◽  
Temperature Range

2-Deoxyribose Radicals in the Gas Phase and Aqueous Solution. Transient Intermediates of Hydrogen Atom Abstraction from 2-Deoxyribofuranose

2005 ◽  
Vol 70 (11) ◽  
pp. 1769-1786 ◽  
Author(s):  
Luc A. Vannier ◽  
Chunxiang Yao ◽  
František Tureček
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Computational Study ◽  
Hydrogen Atom Abstraction ◽  
Oh Radical ◽  
Free Energies ◽  
Intramolecular Hydrogen ◽  
Solvation Free Energies ◽  
Transient Intermediates

A computational study at correlated levels of theory is reported to address the structures and energetics of transient radicals produced by hydrogen atom abstraction from C-1, C-2, C-3, C-4, C-5, O-1, O-3, and O-5 positions in 2-deoxyribofuranose in the gas phase and in aqueous solution. In general, the carbon-centered radicals are found to be thermodynamically and kinetically more stable than the oxygen-centered ones. The most stable gas-phase radical, 2-deoxyribofuranos-5-yl (5), is produced by H-atom abstraction from C-5 and stabilized by an intramolecular hydrogen bond between the O-5 hydroxy group and O-1. The order of radical stabilities is altered in aqueous solution due to different solvation free energies. These prefer conformers that lack intramolecular hydrogen bonds and expose O-H bonds to the solvent. Carbon-centered deoxyribose radicals can undergo competitive dissociations by loss of H atoms, OH radical, or by ring cleavages that all require threshold dissociation or transition state energies >100 kJ mol-1. This points to largely non-specific dissociations of 2-deoxyribose radicals when produced by exothermic hydrogen atom abstraction from the saccharide molecule. Oxygen-centered 2-deoxyribose radicals show only marginal thermodynamic and kinetic stability and are expected to readily fragment upon formation.

A computational study of the radical–radical reaction of O(3P) + C2H5 with comparisons to gas-phase kinetics and crossed-beam experiments

2011 ◽  
Vol 129 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Se-Hee Jung ◽  
Yong-Pal Park ◽  
Kyoo-Weon Kang ◽  
Min-Jin Park ◽  
Jong-Ho Choi
Keyword(s):  
Gas Phase ◽  
Computational Study ◽  
Radical Reaction ◽  
Gas Phase Kinetics

Gas-phase OH radical-initiated oxidation of the 3-halopropenes studied by PLP-LIF in the temperature range 228–388K

2003 ◽  
Vol 37 (21) ◽  
pp. 2919-2926 ◽  
Author(s):  
José Albaladejo ◽  
Bernabé Ballesteros ◽  
Elena Jiménez ◽  
Yolanda Dı́az de Mera ◽  
Ernesto Martı́nez
Keyword(s):  
Gas Phase ◽  
Oh Radical ◽  
Temperature Range

Reaction of OH radicals with 5-hydroxy-2-pentanone: formation yield of 4-oxopentanal and its OH radical reaction rate constant

2013 ◽  
Vol 10 (3) ◽  
pp. 145 ◽  
Author(s):  
Sara M. Aschmann ◽  
Janet Arey ◽  
Roger Atkinson
Keyword(s):  
Gas Phase ◽  
Rate Constant ◽  
First Generation ◽  
Solid Phase ◽  
Radical Reaction ◽  
Oh Radicals ◽  
Oh Radical ◽  
Aerosol Formation ◽  
Gas Phase Reactions ◽  
Concentration Data

Environmental context Alkanes, major constituents of vehicle exhausts, are emitted to the atmosphere where they react, chiefly by gas-phase reactions with the hydroxyl radical, to form products which can also react further. In laboratory experiments, we studied the further reactions of a model first-generation alkane reaction product. Understanding alkane reaction chains is important because the toxicity, secondary aerosol formation and other properties of vehicle emissions can change as new compounds are formed. Abstract 1,4-Hydroxycarbonyls are major products of the gas-phase reactions of alkanes with OH radicals, and in the atmosphere they will react with OH radicals or undergo acid-catalysed cyclisation with subsequent dehydration to form highly reactive dihydrofurans. 3-Oxobutanal (CH3C(O)CH2CHO) and 4-oxopentanal (CH3C(O)CH2CH2CHO) are first-generation products of the OH radical-initiated reaction of 5-hydroxy-2-pentanone (CH3C(O)CH2CH2CH2OH). The behaviours of 3-oxobutanal and 4-oxopentanal have been monitored during OH+5-hydroxy-2-pentanone reactions carried out in the presence of NO, using solid phase microextraction fibres coated with O-(2,3,4,5,6,-pentafluorobenzyl)hydroxyl amine (PFBHA) for on-fibre derivatisation of carbonyl compounds and an annular denuder coated with XAD resin and further coated with PFBHA. The time-concentration data for 4-oxopentanal during OH+5-hydroxy-2-pentanone reactions were independent of relative humidity (0–50%), and were consistent with a rate constant for OH+4-oxopentanal of (1.2±0.5)×10–11cm3 molecule–1s–1 at 296±2K, a factor of 2 lower than both literature rate constants for other aldehydes and that estimated using a structure-reactivity approach. The molar formation yield for 4-oxopentanal from OH+5-hydroxy-2-pentanone in the presence of NO was determined to be 17±5%, consistent with predictions based on a structure-reactivity relationship and current knowledge of the subsequent reaction mechanisms.

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