Laser photolysis study on reactions of sulfate radical and nitrate radical with chlorate ion in aqueous solutions Formation and reduction potential of ClO3 radical

1997 ◽  
Vol 93 (4) ◽  
pp. 533-536 ◽  
Author(s):  
Zhihua Zuo ◽  
Yosuke Katsumura ◽  
Kiyotaka Ueda ◽  
Kenkichi Ishigure
Keyword(s):  
Aqueous Solutions ◽  
Reduction Potential ◽  
Laser Photolysis ◽  
Sulfate Radical ◽  
Nitrate Radical

Laser photolysis study on the reaction of nitrate radical with tributylphosphate and its analogues—comparison with sulfate radical

2004 ◽  
Vol 6 (6) ◽  
pp. 1264-1268 ◽  
Author(s):  
Hui He ◽  
Mingzhang Lin ◽  
Yusa Muroya ◽  
Hisaaki Kudo ◽  
Yosuke Katsumura
Keyword(s):  
Laser Photolysis ◽  
Sulfate Radical ◽  
Nitrate Radical

Hydroxyl radical, sulfate radical and nitrate radical reactivity towards crown ethers in aqueous solutions

2012 ◽  
Vol 81 (5) ◽  
pp. 524-530 ◽  
Author(s):  
L.K. Wan ◽  
J. Peng ◽  
M.Z. Lin ◽  
Y. Muroya ◽  
Y. Katsumura ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radical ◽  
Crown Ethers ◽  
Sulfate Radical ◽  
Nitrate Radical ◽  
Radical Reactivity

scholarly journals Spectral Probe for Electron Transfer and Addition Reactions of Azide Radicals with Substituted Quinoxalin-2-Ones in Aqueous Solutions

2021 ◽  
Vol 22 (2) ◽  
pp. 633
Author(s):  
Konrad Skotnicki ◽  
Slawomir Ostrowski ◽  
Jan Cz. Dobrowolski ◽  
Julio R. De la Fuente ◽  
Alvaro Cañete ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Density Functional ◽  
Reduction Potential ◽  
Biological Significance ◽  
Radical Cations ◽  
Basis Sets ◽  
Double Bonds ◽  
Reduction Potentials

The azide radical (N3●) is one of the most important one-electron oxidants used extensively in radiation chemistry studies involving molecules of biological significance. Generally, it was assumed that N3● reacts in aqueous solutions only by electron transfer. However, there were several reports indicating the possibility of N3● addition in aqueous solutions to organic compounds containing double bonds. The main purpose of this study was to find an experimental approach that allows a clear assignment of the nature of obtained products either to its one-electron oxidation or its addition products. Radiolysis of water provides a convenient source of one-electron oxidizing radicals characterized by a very broad range of reduction potentials. Two inorganic radicals (SO4●−, CO3●−) and Tl2+ ions with the reduction potentials higher, and one radical (SCN)2●− with the reduction potential slightly lower than the reduction potential of N3● were selected as dominant electron-acceptors. Transient absorption spectra formed in their reactions with a series of quinoxalin-2-one derivatives were confronted with absorption spectra formed from reactions of N3● with the same series of compounds. Cases, in which the absorption spectra formed in reactions involving N3● differ from the absorption spectra formed in the reactions involving other one-electron oxidants, strongly indicate that N3● is involved in the other reaction channel such as addition to double bonds. Moreover, it was shown that high-rate constants of reactions of N3● with quinoxalin-2-ones do not ultimately prove that they are electron transfer reactions. The optimized structures of the radical cations (7-R-3-MeQ)●+, radicals (7-R-3-MeQ)● and N3● adducts at the C2 carbon atom in pyrazine moiety and their absorption spectra are reasonably well reproduced by density functional theory quantum mechanics calculations employing the ωB97XD functional combined with the Dunning’s aug-cc-pVTZ correlation-consistent polarized basis sets augmented with diffuse functions.

Laser photolysis study of the triplet states of phthalocyanines on the surface of silica nanoparticles in aqueous solutions

2013 ◽  
Vol 47 (3) ◽  
pp. 98-102 ◽  
Author(s):  
N. B. Sul’timova ◽  
P. P. Levin ◽  
A. V. Lobanov ◽  
A. M. Muzafarov
Keyword(s):  
Aqueous Solutions ◽  
Silica Nanoparticles ◽  
Laser Photolysis ◽  
Triplet States

Reduction potential of the nitrate radical in aqueous solution

1992 ◽  
Vol 31 (24) ◽  
pp. 5135-5136 ◽  
Author(s):  
Pei Yun Jiang ◽  
Yosuke Katsumura ◽  
Kenkichi Ishigure ◽  
Yoichi Yoshida
Keyword(s):  
Aqueous Solution ◽  
Reduction Potential ◽  
Nitrate Radical

scholarly journals Investigation of potential interferences in the detection of atmospheric RO<sub><i>x</i></sub> radicals by laser-induced fluorescence under dark conditions

2015 ◽  
Vol 8 (11) ◽  
pp. 12475-12523
Author(s):  
H. Fuchs ◽  
Z. Tan ◽  
A. Hofzumahaus ◽  
S. Broch ◽  
H.-P. Dorn ◽  
...  
Keyword(s):  
Direct Detection ◽  
Experimental Studies ◽  
Chemical Conversion ◽  
Ambient Air ◽  
Laser Induced Fluorescence ◽  
Laser Photolysis ◽  
Interference Signal ◽  
Nitrate Radical ◽  
Peroxy Radicals ◽  
Atmospheric Conditions

Abstract. Direct detection of highly reactive, atmospheric hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime conditions. For laboratory experiments, the inlet of the instrument was overflown by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm−3 OH for a mixing ratio of 5 ppbv acetone. Under most atmospheric conditions, this interference is negligible. No significant interferences were found for atmospheric concentrations of reactants during ozonolysis experiments. Only for α-pinene, limonene, and isoprene at reactant concentrations which are orders of magnitude higher than in the atmosphere artificial OH could be detected. The value of the interference depends on the turnover rate of the ozonolysis reaction. For example, an apparent OH concentration of approximately 1 × 106 cm−3 is observed, if 5.8 ppbv limonene reacts with 600 ppbv ozone. Experiments with the nitrate radical NO3 reveal a small interference signal in the OH, HO2 and RO2 detection. Dependencies on experimental parameters point to artificial OH formation by surface reactions at the chamber walls or in molecular clusters in the gas expansion. The signal scales with the presence of NO3 giving equivalent radical concentrations of 1.1 × 105 cm−3 OH, 1 × 107 cm−3 HO2, and 1.7 × 107 cm−3 RO2 per 10 pptv NO3.

scholarly journals Investigation of potential interferences in the detection of atmospheric RO<sub><i>x</i></sub> radicals by laser-induced fluorescence under dark conditions

2016 ◽  
Vol 9 (4) ◽  
pp. 1431-1447 ◽  
Author(s):  
Hendrik Fuchs ◽  
Zhaofeng Tan ◽  
Andreas Hofzumahaus ◽  
Sebastian Broch ◽  
Hans-Peter Dorn ◽  
...  
Keyword(s):  
Direct Detection ◽  
Experimental Studies ◽  
Chemical Conversion ◽  
Ambient Air ◽  
Laser Induced Fluorescence ◽  
Laser Photolysis ◽  
Interference Signal ◽  
Nitrate Radical ◽  
Peroxy Radicals ◽  
Atmospheric Conditions

Abstract. Direct detection of highly reactive, atmospheric hydroxyl radicals (OH) is widely accomplished by laser-induced fluorescence (LIF) instruments. The technique is also suitable for the indirect measurement of HO2 and RO2 peroxy radicals by chemical conversion to OH. It requires sampling of ambient air into a low-pressure cell, where OH fluorescence is detected after excitation by 308 nm laser radiation. Although the residence time of air inside the fluorescence cell is typically only on the order of milliseconds, there is potential that additional OH is internally produced, which would artificially increase the measured OH concentration. Here, we present experimental studies investigating potential interferences in the detection of OH and peroxy radicals for the LIF instruments of Forschungszentrum Jülich for nighttime conditions. For laboratory experiments, the inlet of the instrument was over flowed by excess synthetic air containing one or more reactants. In order to distinguish between OH produced by reactions upstream of the inlet and artificial signals produced inside the instrument, a chemical titration for OH was applied. Additional experiments were performed in the simulation chamber SAPHIR where simultaneous measurements by an open-path differential optical absorption spectrometer (DOAS) served as reference for OH to quantify potential artifacts in the LIF instrument. Experiments included the investigation of potential interferences related to the nitrate radical (NO3, N2O5), related to the ozonolysis of alkenes (ethene, propene, 1-butene, 2,3-dimethyl-2-butene, α-pinene, limonene, isoprene), and the laser photolysis of acetone. Experiments studying the laser photolysis of acetone yield OH signals in the fluorescence cell, which are equivalent to 0.05 × 106 cm−3 OH for a mixing ratio of 5 ppbv acetone. Under most atmospheric conditions, this interference is negligible. No significant interferences were found for atmospheric concentrations of reactants during ozonolysis experiments. Only for propene, α-pinene, limonene, and isoprene at reactant concentrations, which are orders of magnitude higher than in the atmosphere, could artificial OH be detected. The value of the interference depends on the turnover rate of the ozonolysis reaction. For example, an apparent OH concentration of approximately 1 × 106 cm−3 is observed when 5.8 ppbv limonene reacts with 600 ppbv ozone. Experiments with the nitrate radical NO3 reveal a small interference signal in the OH, HO2, and RO2 detection. Dependencies on experimental parameters point to artificial OH formation by surface reactions at the chamber walls or in molecular clusters in the gas expansion. The signal scales with the presence of NO3 giving equivalent radical concentrations of 1.1 × 105 cm−3 OH, 1 × 107 cm−3 HO2, and 1.7 × 107 cm−3 RO2 per 10 pptv NO3.

A Pulse Radiolysis Study of the Reaction of the Sulfate Radical Ion in Aqueous Solutions of Styrene

1979 ◽  
Vol 32 (12) ◽  
pp. 2611 ◽  
Author(s):  
NA McAskill ◽  
DF Sangster
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Pulse Radiolysis ◽  
Cation Radical ◽  
Ultraviolet Absorption ◽  
Sulfate Radical ◽  
Transient Species ◽  
Acetonitrile Solutions ◽  
Type Radical

The ultraviolet absorption spectra of the transient species formed during the pulse radiolysis of styrene and peroxydisulfate (S2O82)solutions showed that a benzyl-type radical was formed from styrene and the SO4- radical. The effect of adding Cl- was also studied. These results are in conflict with the claim1 that a phenylethyl radical was formed from SO4-' via the styrene cation radical. That study was made on acetonitrile solutions of styrene, S2O82-, CuCl2 and LiCl and the present results suggest that up to 70% of the SO4-' radicals may have been converted into Cl2-1 radical which then reacted with styrene.

Degradation of p-chloroaniline by FeO3−xH3−2x/Fe0 in the presence of persulfate in aqueous solution

RSC Advances ◽  
2015 ◽  
Vol 5 (51) ◽  
pp. 41079-41087 ◽  
Author(s):  
Imtyaz Hussain ◽  
Yongqing Zhang ◽  
Shaobin Huang ◽  
Qunyu Gao
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Organic Compounds ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Sulfate Radical ◽  
Oxidation Processes

Sulfate radical based advanced oxidation processes are promising techniques for the removal of organic compounds in aqueous solutions.

Sign in / Sign up

Export Citation Format

Share Document