Hydroxyl Radical Reactivity with Diethylhydroxylamine

Science ◽  
1977 ◽  
Vol 197 (4311) ◽  
pp. 1365-1367 ◽  
Author(s):  
R. A. GORSE ◽  
R. R. LII ◽  
B. B. SAUNDERS
2002 ◽  
Vol 124 (22) ◽  
pp. 6304-6311 ◽  
Author(s):  
Junbo Feng ◽  
Sudhir N. V. K. Aki ◽  
John E. Chateauneuf ◽  
Joan F. Brennecke

2020 ◽  
Vol 740 ◽  
pp. 139897
Author(s):  
Jiaru Li ◽  
Yosuke Sakamoto ◽  
Nanase Kohno ◽  
Tomihide Fujii ◽  
Kohei Matsuoka ◽  
...  

2010 ◽  
Vol 132 (9) ◽  
pp. 2907-2913 ◽  
Author(s):  
Susan Mitroka ◽  
Stephanie Zimmeck ◽  
Diego Troya ◽  
James M. Tanko

Author(s):  
Donald T. Sawyer ◽  
R. J. P. Williams

Oxygen radicals are defined as those molecules that contain an oxygen atom with an unpaired, nonbonding electron (e.g., HO·). Although triplet dioxygen (·O2·) and superoxide ion (O2 - ·) come under this definition, their nonradical chemistry dominates their reactivity, which is discussed in Chapters 6 (·O2·) and 7 (O2-·). The hydroxyl radical (HO·) is the most reactive member of the family of oxygen radicals [HO·, RO·, ·O·, HOO·, ROO·, and RC(O)O·], and is the focus of most oxygen radical research. In the gas phase the dramatic example of oxygen radical reactivity with hydrocarbon substrates is combustion, which is initiated by HO· (or RO· or MO·) and propagated by ·O2· and ·O·.


2014 ◽  
Vol 14 (6) ◽  
pp. 2923-2937 ◽  
Author(s):  
R. F. Hansen ◽  
S. M. Griffith ◽  
S. Dusanter ◽  
P. S. Rickly ◽  
P. S. Stevens ◽  
...  

Abstract. Total hydroxyl radical (OH) reactivity was measured at the PROPHET (Program for Research on Oxidants: PHotochemistry, Emissions, and Transport) forested field site in northern Michigan during the 2009 Community Atmosphere–Biosphere INteraction EXperiment (CABINEX). OH reactivity measurements were made with a turbulent-flow reactor instrument at three heights from the forest floor above (21 and 31 m) and below (6 m) the canopy at three different time periods during the CABINEX campaign. In addition to total OH reactivity measurements, collocated measurements of volatile organic compounds (VOCs), inorganic species, and ambient temperature were made at the different heights. These ancillary measurements were used to calculate the total OH reactivity, which was then compared to the measured values. Discrepancies between the measured and calculated OH reactivity, on the order of 1–24 s−1, were observed during the daytime above the canopy at the 21 and 31 m heights, as previously reported for this site. The measured OH reactivity below the canopy during the daytime was generally lower than that observed above the canopy. Closer analysis of the measurements of OH reactivity and trace gases suggests that the missing OH reactivity could come from oxidation products of VOCs. These results suggest that additional unmeasured trace gases, likely oxidation products, are needed to fully account for the OH reactivity measured during CABINEX.


2013 ◽  
Vol 13 (18) ◽  
pp. 9497-9514 ◽  
Author(s):  
P. M. Edwards ◽  
M. J. Evans ◽  
K. L. Furneaux ◽  
J. Hopkins ◽  
T. Ingham ◽  
...  

Abstract. OH (hydroxyl radical) reactivity, the inverse of the chemical lifetime of the hydroxyl radical, was measured for 12 days in April 2008 within a tropical rainforest on Borneo as part of the OP3 (Oxidant and Particle Photochemical Processes) project. The maximum observed value was 83.8 ± 26.0 s−1 with the campaign averaged noontime maximum being 29.1 ± 8.5 s−1. The maximum OH reactivity calculated using the diurnally averaged concentrations of observed sinks was ~ 18 s−1, significantly less than the observations, consistent with other studies in similar environments. OH reactivity was dominated by reaction with isoprene (~ 30%). Numerical simulations of isoprene oxidation using the Master Chemical Mechanism (v3.2) in a highly simplified physical and chemical environment show that the steady state OH reactivity is a linear function of the OH reactivity due to isoprene alone, with a maximum multiplier, to account for the OH reactivity of the isoprene oxidation products, being equal to the number of isoprene OH attackable bonds (10). Thus the emission of isoprene constitutes a significantly larger emission of reactivity than is offered by the primary reaction with isoprene alone, with significant scope for the secondary oxidation products of isoprene to constitute the observed missing OH reactivity. A physically and chemically more sophisticated simulation (including physical loss, photolysis, and other oxidants) showed that the calculated OH reactivity is reduced by the removal of the OH attackable bonds by other oxidants and photolysis, and by physical loss (mixing and deposition). The calculated OH reactivity is increased by peroxide cycling, and by the OH concentration itself. Notable in these calculations is that the accumulated OH reactivity from isoprene, defined as the total OH reactivity of an emitted isoprene molecule and all of its oxidation products, is significantly larger than the reactivity due to isoprene itself and critically depends on the chemical and physical lifetimes of intermediate species. When constrained to the observed diurnally averaged concentrations of primary VOCs (volatile organic compounds), O3, NOx and other parameters, the model underestimated the observed diurnal mean OH reactivity by 30%. However, it was found that (1) the short lifetimes of isoprene and OH, compared to those of the isoprene oxidation products, lead to a large variability in their concentrations and so significant variation in the calculated OH reactivity; (2) uncertainties in the OH chemistry in these high isoprene environments can lead to an underestimate of the OH reactivity; (3) the physical loss of species that react with OH plays a significant role in the calculated OH reactivity; and (4) a missing primary source of reactive carbon would have to be emitted at a rate equivalent to 50% that of isoprene to account for the missing OH sink. Although the presence of unmeasured primary emitted VOCs contributing to the measured OH reactivity is likely, evidence that these primary species account for a significant fraction of the unmeasured reactivity is not found. Thus the development of techniques for the measurement of secondary multifunctional carbon compounds is needed to close the OH reactivity budget.


2012 ◽  
Vol 81 (5) ◽  
pp. 524-530 ◽  
Author(s):  
L.K. Wan ◽  
J. Peng ◽  
M.Z. Lin ◽  
Y. Muroya ◽  
Y. Katsumura ◽  
...  

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