The atmospheric oxidation of hydroxyacetone: Chemistry of activated and stabilized CH₃C(O)CH(OH)OO• radicals between 252 and 298 K

Abstract

The products of the Cl‐atom‐initiated oxidation of hydroxyacetone (HYAC, CH3C(O)CH2OH) have been examined under conditions relevant to the earth's lower atmosphere. Over the range of temperatures studied (252‐298 K), in the absence of NOx, methylglyoxal (CH3C(=O)CH=O, MGLY) was formed with a primary yield >84% (96 ± 9% at 298 K), while in the presence of elevated NOx, MGLY and formic acid were both formed as major primary products. In contrast to a previous study, acetic acid was not identified as a major primary product under the conditions studied. The results are quantitatively interpreted from a consideration of the formation of a stabilized CH3C(O)CH(OH)OO• radical, either in a ≈50% yield from the addition of O2 to CH3C(O)CH•(OH) or in 100% yield from the addition of HO2 to MGLY. At high temperature and low NOx, decomposition of the stabilized CH3C(O)CH(OH)OO• radical to MGLY is favored, while lower temperatures and conditions of high NOx favor bimolecular reactions of the stabilized radical, with subsequent production of formic acid. Analysis of the data allows for a semiquantitative determination of K3 = (2.9 ± 0.4) × 10−16 cm3 molecule−1, for the HO2 + MGLY ↔ CH3C(O)CH(OH)OO• equilibrium process at 298 K and a roughly order of magnitude increase in K3 at 252 K.

Confirmation of PNNL Quantitative Infrared Cross-Sections for Isobutane

“…There are multiple applications where the NWIR data are used in different branches of science and engineering. Some examples that use high-resolution rotational–vibrational data in conjunction with PNNL integrated intensities, largely for band assignments, include molecules such as propane and freons such as HFC-43-10mee as well as laser detection, including alkanes by, for example, Farooq et al All such studies have corroborated the PNNL values, but care had to be taken in regard to PNNL’s use of (a) decadic logarithms, (b) concentration units of μmol/mol as recommended by IUPAC and the conversion to the units of cm 2 /molecule, a unit more commonly used in molecular spectroscopy, and (c) the fact that all NWIR data are scaled to a number density corresponding to 1 atm of gas at 296 K. In an analogous fashion, many researchers have used the NWIR data for infrared spectroscopy to monitor chemical kinetics , as well as for radiative transfer calculations and atmospheric chemistry studies. ,− In almost all cases where researchers have made independent measurements of any of the 462 published spectra in the PNNL database, the results agree to ca. 4% or better.…”

“…The data were originally published and made available 1,5 in 2004, and thousands of copies were distributed on a web site, with many of the molecular absorption cross-sections more recently made available as a new product on the HITRAN web site. 8 The spectral data have been used for applications including ambient 9,10 and laboratory monitoring, 11,12 input to radiative transfer models, 13,14 and other endeavors such as atmospheric chemistry, 15,16 gas-phase chemical kinetics, 17,18 combustion science, 19,20 and even fundamental vibrational assignments. 21 Recently, Bernath, Hewett, and co-workers 22−25 have investigated the structure and band strengths of isobutane, C 4 H 10 , for possible monitoring of this species on gas-giant planets such as Jupiter and Saturn as well as the gas-phase composition of their moons such as Saturn's largest, Titan.…”

“…The data were originally published and made available , in 2004, and thousands of copies were distributed on a web site, with many of the molecular absorption cross-sections more recently made available as a new product on the HITRAN web site . The spectral data have been used for applications including ambient , and laboratory monitoring, , input to radiative transfer models, , and other endeavors such as atmospheric chemistry, , gas-phase chemical kinetics, , combustion science, , and even fundamental vibrational assignments …”

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the South-West Indian Ocean

“…This may account for part of the HCOOH production during transport. However, recent studies indicate that this production is effective only in high NO x conditions that are not realistic in a natural environment (Orlando et al, 2012;Orlando and Tyndall, 2020). Production of HCOOH from glycolaldehyde is thus most likely only a minor source.…”

Intramolecular proton transfer in the isomerization of hydroxyacetone: Characterization based on reaction force analysis and the bond fragility spectrum

“…Additionally, hydroxyacetone is of interest in atmospheric chemistry as a second-generation product of volatile organic compounds interacting with atmospheric free radicals in the troposphere, leading to numerous studies on its mechanism of oxidation. [34][35][36][37][38][39][40] A general scheme for the isomerization of hydroxyacetone to 2-hydroxypropanal is shown in Figure 1 with the DPT mechanism occurring via three unique pathways, the first two pathways are stepwise processes that proceed through stable isomers (Z and E) of their shared enediol intermediate. The third pathway is a concerted mechanism that was recently discovered by Gabriel da Silva and coworkers, [41] it bypasses the enediol intermediate and was found to be energetically favorable by approximately 20 kcal mol −1 suggesting this may be a general mechanism of importance for all hydroxycarbonyls.…”