Kinetic Studies of Singlet Oxygen [4 + 2]-Cycloadditions with Cyclic 1,3-Dienes in 28 Solvents

1995 ◽  
Vol 117 (36) ◽  
pp. 9159-9164 ◽  
Author(s):  
Jean-Marie Aubry ◽  
Bernadette Mandard-Cazin ◽  
Michel Rougee ◽  
Rene V. Bensasson
Keyword(s):  
Singlet Oxygen ◽  
Kinetic Studies

Kinetic studies of excited singlet oxygen atom O( 1 D) reactions with ethanol

2021 ◽  
Author(s):  
Hongtao Zhong ◽  
Chao Yan ◽  
Chu C. Teng ◽  
Timothy Y. Chen ◽  
Gerard Wysocki ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Singlet Oxygen ◽  
Kinetic Studies ◽  
Excited Singlet

Article

1998 ◽  
Vol 76 (12) ◽  
pp. 1805-1816
Author(s):  
L Ross C Barclay ◽  
Jennifer K Grandy ◽  
Heather D MacKinnon ◽  
Heather C Nichol ◽  
Melinda R Vinqvist
Keyword(s):  
Oxygen Uptake ◽  
Singlet Oxygen ◽  
Sodium Azide ◽  
Lignin Content ◽  
Sodium Dodecyl ◽  
Kinetic Studies ◽  
Product Distribution ◽  
Geometrical Isomers ◽  
Photo Oxidation ◽  
Tert Butyl

3,5-Di-tert-butyl-ortho-quinone, 6, and 1-(3,4-dimethoxyphenyl-2-(2-methoxyphenoxy)-1-propanone, 7, models for oxidized lignin and for lignin, were used as sensitizers of photo-oxidation. Product studies by HPLC from oxidation of methyl linoleate in solution sensitized by 6 or 7, and in sodium dodecyl sulfate (SDS) sensitized by 6, showed a product distribution of six hydroperoxides, the four conjugated 9- and 13-hydroperoxides of the geometrical isomers: trans-10, cis-12 (2), cis-9, trans-11 (3), trans-10, trans-12 (4), and trans-9, trans-11 (5)-octadecadienoates plus two nonconjugated hydroperoxides. The higher cis/trans to trans/trans (ct/tt) of geometrical isomers (2 + 3//4 + 5) compared to ct/tt from known thermal free-radical peroxidations (Type 1) indicate that singlet oxygen (Type 2) oxidation occurs in reactions sensitized by 6 or 7. Kinetic studies by oxygen uptake are reported on oxidations of hydrocarbons 1-phenyl-2-methylpropene,8, and trans-stilbene,9, sensitized by the quinone, 6, or by a dye, Rose Bengal. Quenching studies imply singlet oxygen reactions. Milled wood lignin undergoes self-initiated photo-oxidation in water, and oxygen uptake was quenched by sodium azide. Cellobiose, a cellulose model, undergoes sensitized photo-oxidation using model quinone, 6, in a mixture of tert-butyl alcohol and water or using the sensitizers benzophenone or the lignin model, 7, delivered on a solid support, silica gel, and these oxidations were quenched with sodium azide. These results implicate singlet oxygen in the photo-yellowing of high lignin content wood pulps.Key words: lignin models, ortho-quinone, photo-oxidation, singlet oxygen, lignin, cellobiose.

Kinetic Studies of Excited Singlet Oxygen Atoms O(1D) Reactions with Fuels in Plasma Assisted Combustion

2019 ◽  
Author(s):  
Hongtao Zhong ◽  
Chao Yan ◽  
Chu C. Teng ◽  
Timothy Chen ◽  
Aric C. Rousso ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Kinetic Studies ◽  
Excited Singlet ◽  
Plasma Assisted Combustion ◽  
Oxygen Atoms

scholarly journals Selective Generation of Singlet Oxygen in Chloride Accelerated Copper Fenton Chemistry

2018 ◽  
Author(s):  
Andrew Carrier ◽  
Collins Nganou ◽  
David Oakley ◽  
Yongli Chen ◽  
Ken Oakes ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Oxygen Sensor ◽  
Kinetic Studies ◽  
Side Reactions ◽  
Fenton Chemistry ◽  
Co Catalyst ◽  
Novel Method ◽  
Selective Generation ◽  
Antimicrobial Treatments

<p>Singlet oxygen (<sup>1</sup>O<sub>2</sub>), a widely used reactive oxygen species (ROS) in industry and biomedical applications, plays a fundamental role throughout nature. We report a novel method to generate <sup>1</sup>O<sub>2</sub>selectively and efficiently through copper-based Fenton chemistry under circumneutral conditions enhanced by chloride as co-catalyst, with reactivity completely different than that observed in classical iron-based Fenton chemistry. The mechanism of its formation was elucidated through the kinetic studies of orthogonally reactive reporter molecules, i.e., singlet oxygen sensor green, 4-hydroxy-2,2,6,6-tetramethylpiperidine, and phenol, and selective ROS quenchers. This method selectively generates <sup>1</sup>O<sub>2</sub><i>in situ</i>neither relying on photosensitization nor resulting in side reactions, and together with the mechanistic understanding of the Cu-Fenton reaction, not only opens new possibilities in many industries, such as organic synthesis and antimicrobial treatments, but also provides insight into Cu and H<sub>2</sub>O<sub>2</sub>containing chemical, environmental, and biological systems.</p>

Singlet oxygen scavenging by α-tocopherol and β-carotene: Kinetic studies in phospholipid membranes and ethanol solution

BioFactors ◽  
1998 ◽  
Vol 7 (1-2) ◽  
pp. 31-40 ◽  
Author(s):  
Kenji Fukuzawa ◽  
Yasuki Inokami ◽  
Akira Tokumura ◽  
Junji Terao ◽  
Asahi Suzuki
Keyword(s):  
Singlet Oxygen ◽  
Kinetic Studies ◽  
Ethanol Solution ◽  
Phospholipid Membranes ◽  
Oxygen Scavenging ◽  
Β Carotene

scholarly journals Selective Generation of Singlet Oxygen in Chloride Accelerated Copper Fenton Chemistry

2018 ◽  
Author(s):  
Andrew Carrier ◽  
Collins Nganou ◽  
David Oakley ◽  
Yongli Chen ◽  
Ken Oakes ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Oxygen Sensor ◽  
Kinetic Studies ◽  
Side Reactions ◽  
Fenton Chemistry ◽  
Co Catalyst ◽  
Novel Method ◽  
Selective Generation ◽  
Antimicrobial Treatments

<p>Singlet oxygen (<sup>1</sup>O<sub>2</sub>), a widely used reactive oxygen species (ROS) in industry and biomedical applications, plays a fundamental role throughout nature. We report a novel method to generate <sup>1</sup>O<sub>2</sub>selectively and efficiently through copper-based Fenton chemistry under circumneutral conditions enhanced by chloride as co-catalyst, with reactivity completely different than that observed in classical iron-based Fenton chemistry. The mechanism of its formation was elucidated through the kinetic studies of orthogonally reactive reporter molecules, i.e., singlet oxygen sensor green, 4-hydroxy-2,2,6,6-tetramethylpiperidine, and phenol, and selective ROS quenchers. This method selectively generates <sup>1</sup>O<sub>2</sub><i>in situ</i>neither relying on photosensitization nor resulting in side reactions, and together with the mechanistic understanding of the Cu-Fenton reaction, not only opens new possibilities in many industries, such as organic synthesis and antimicrobial treatments, but also provides insight into Cu and H<sub>2</sub>O<sub>2</sub>containing chemical, environmental, and biological systems.</p>

Synthesis and kinetic studies of a novel singlet oxygen donor with acceptor-binding capability

1992 ◽  
Vol 2 (9) ◽  
pp. 1137-1140 ◽  
Author(s):  
Harry H. Wasserman ◽  
Ta Yen Ching ◽  
Bruce H. Lipshutz ◽  
Haruo Matsuyama ◽  
Frank E. Scully ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Kinetic Studies ◽  
Oxygen Donor ◽  
Binding Capability
Sign in / Sign up

Export Citation Format

Share Document