scholarly journals Environmental photochemistry of fenamate NSAIDs and their radical intermediates

2017 ◽  
Vol 19 (5) ◽  
pp. 656-665 ◽  
Author(s):  
Caroline A. Davis ◽  
Paul R. Erickson ◽  
Kristopher McNeill ◽  
Elisabeth M. L. Janssen
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Reaction Pathways ◽  
Radical Intermediates ◽  
Environmental Photochemistry ◽  
Transfer Mechanisms

Photodegradation of five NSAIDs was studied by steady-state and laser-flash photolysis quantifying reaction pathways and kinetics via electron transfer mechanisms.

Diazonium salts in photochemistry. I. Quenching of triplet photosensitizers

1982 ◽  
Vol 60 (17) ◽  
pp. 2286-2291 ◽  
Author(s):  
J. C. Scaiano ◽  
Nguyen Kim-Thuan
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Diazonium Salt ◽  
Laser Flash ◽  
High Energy ◽  
Diazonium Salts ◽  
Transfer Mechanisms ◽  
Degree Of Charge Transfer

Aromatic diazonium tetrafluoroborates have been shown to be excellent triplet quenchers. Typical rate constants obtained using laser flash photolysis are in the 1–10 × 109 M−1 s−1 range in acetonitrile at 300 K. With most sensitizers the interaction leads to the dediazoniation reaction, via either energy transfer or electron transfer mechanisms. In the case of anthracene, where the rate constant for benzenediazonium tetrafluoroborate is (5.4 ± 0.3) × 109 M−1 s−1, the reaction involves the transfer of an electron, leading to the formation of anthracene radical-cation, which has been characterized by absorption spectroscopy. High energy sensitizers, such as benzophenone, are believed to lead to aryl cations and nitrogen; the process may involve some degree of charge transfer, since it is somewhat faster when electron donating substituents are present in the diazonium salt.

Electron transfer sensitized photolysis of 'onium salts

1988 ◽  
Vol 66 (2) ◽  
pp. 319-324 ◽  
Author(s):  
R. J. DeVoe ◽  
M. R. V. Sahyun ◽  
Einhard Schmidt ◽  
N. Serpone ◽  
D. K. Sharma
Keyword(s):  
Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Quantitative Model ◽  
Intersystem Crossing ◽  
Single Electron Transfer ◽  
Onium Salts ◽  
Encounter Complex ◽  
Back Electron Transfer

We have studied the anthracene-sensitized photolyses of both diphenyliodonium and triphenylsulphonium salts in solution using both steady-state and laser flash photolysis techniques. Photoproducts, namely, phenylated anthracenes along with iodobenzene or diphenylsulphide, respectively, are obtained from both salts with quantum efficiencies of ca. 0.1 at 375 nm. We infer the intermediacy of diphenyliodo and triphenylsulphur radicals formed by single electron transfer from the singlet-excited anthracene. We have developed a quantitative model of this chemistry, and identify the principal sources of inefficiency as back electron transfer, which occurs at nearly the theoretically limiting rate, intersystem crossing from the initially formed sensitizer–'onium salt encounter complex, and in-cage radical recombination.

Phototransformations of bridgehead-substituted dibenzobarrelenes. Steady-state and laser flash photolysis studies

1987 ◽  
Vol 52 (25) ◽  
pp. 5512-5517 ◽  
Author(s):  
S. Pratapan ◽  
K. Ashok ◽  
D. R. Cyr ◽  
P. K. Das ◽  
M. V. George
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash

Laser flash photolysis studies of intramolecular electron transfer in milk xanthine oxidase

Biochemistry ◽  
1983 ◽  
Vol 22 (23) ◽  
pp. 5270-5279 ◽  
Author(s):  
Anjan Bhattacharyya ◽  
Gordon Tollin ◽  
Michael Davis ◽  
Dale E. Edmondson
Keyword(s):  
Electron Transfer ◽  
Xanthine Oxidase ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Intramolecular Electron Transfer
Sign in / Sign up

Export Citation Format

Share Document