Detection of singlet oxygen and its role in dye-sensitized photooxidation in aqueous and micellar solutions

Biochimie ◽  
1986 ◽  
Vol 68 (6) ◽  
pp. 807-811 ◽  
Author(s):  
Ivan Kraljić
Keyword(s):  
Singlet Oxygen ◽  
Micellar Solutions ◽  
Dye Sensitized

New Insight into the Reaction of Singlet Oxygen with Sulfur-Containing Cyclic Alkenes:  Dye-Sensitized Photooxygenation of 5,6-Dihydro-1,4-dithiins

2007 ◽  
Vol 72 (26) ◽  
pp. 10075-10080 ◽  
Author(s):  
Flavio Cermola ◽  
Annalisa Guaragna ◽  
Maria Rosaria Iesce ◽  
Giovanni Palumbo ◽  
Raffaella Purcaro ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Dye Sensitized ◽  
Sulfur Containing ◽  
Insight Into ◽  
Cyclic Alkenes

Synthesis and singlet oxygen production of azaphthalocyanines bearing functional derivatives of carboxylic acid

2006 ◽  
Vol 10 (02) ◽  
pp. 122-131 ◽  
Author(s):  
Zbynek Musil ◽  
Petr Zimcik ◽  
Miroslav Miletin ◽  
Kamil Kopecky ◽  
Marek Link ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Singlet Oxygen ◽  
Hexanoic Acid ◽  
Oxygen Production ◽  
Metal Free ◽  
Dye Sensitized ◽  
Structure Activity ◽  
Functional Derivatives ◽  
Derivatives Of ◽  
Free Magnesium

New metal-free, magnesium and zinc azaphthalocyanines ( AzaPc ) were prepared from 6-(3-tert-butylsulfany1-5,6-dicyanopyrazine-2-ylamino)hexanoic acid and its butylester and N,N-diethylamide. Their singlet oxygen production was measured by a dye-sensitized photooxidation of 1,3-diphenylisobenzofuran ( DPBF ) and ΦΔ values were calculated. It was found that the presence of carboxylic acid in the structure of AzaPc decreases their singlet oxygen production. Singlet oxygen activity of the newly prepared compounds (containing mixed alkylamino and alkylsulfanyl peripheral substituents) lies between purely alkylsulfanyl and alkylamino derivatives of AzaPc . This fact further supports previously proposed structure-activity relationships, where alkylsulfanyl derivatives belong to the best singlet oxygen producers while the presence of alkylamino substituents in the structure rapidly decreases their photodynamic properties.

Dye-sensitized photo-oxidation of thiourea by singlet oxygen

1991 ◽  
Vol 60 (1) ◽  
pp. 47-50 ◽  
Author(s):  
V.K. Vaidya ◽  
R.L. Pitlia ◽  
B.V. Kabra ◽  
S.L. Mali ◽  
Suresh C. Ameta
Keyword(s):  
Singlet Oxygen ◽  
Photo Oxidation ◽  
Dye Sensitized

Substituent Effects in Dye-sensitized Photooxidation Reactions of Furans

1972 ◽  
Vol 50 (6) ◽  
pp. 932-938 ◽  
Author(s):  
R. H. Young ◽  
R. L. Martin ◽  
N. Chinh ◽  
C. Mallon ◽  
R. H. Kayser
Keyword(s):  
Singlet Oxygen ◽  
Relative Rate ◽  
Substituent Effects ◽  
Solvent Polarity ◽  
Diels Alder ◽  
Dye Sensitized ◽  
Rate Of Decay ◽  
Relative Rate Constants ◽  
Normal Method ◽  
Substituted Furans

The problems encountered in the normal method used to determine β values (rate of decay of singlet oxygen divided by the rate of its reaction with an organic compound) are discussed. The use of dilute solutions of organic acceptors for our measurements was found to give more reproducible values and simplified kinetics. These β values were used to obtain relative rate constants for a variety of substituted furans. Hammett plots were made to quantitate the substituent effects in order to explore the nature of singlet oxygen in the dye-sensitized photooxidation reactions of these furans. The calculated ρ values were compared with other photooxidation and Diels–Alder reactions. Hammett ρ values in a series of solvents were also calculated for the reaction of singlet oxygen with 2-arylfurans and increasing ρ values were correlated with decreasing solvent polarity.

Fluorescein-photosensitized Furan Oxidation in Methanolic and Reversed Micellar Solutions, Part II Kinetic Analysis

1980 ◽  
Vol 35 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Singlet Oxygen ◽  
Kinetic Analysis ◽  
Rate Constants ◽  
Solvent Polarity ◽  
Radical Mechanism ◽  
Type I ◽  
Type Ii ◽  
Micellar Solutions ◽  
Alkyl Amines ◽  
Reaction Processes

Abstract The 1,3-diphenylisobenzofuran oxidation was investigated in methanolic and dodecyl-ammonium propionate reversed micellar solutions using fluorescein sodium as photosensitizer. The furan oxidation was caused by the singlet oxygen mechanism (Type II). Aniline enhanced remarkably the furan oxidation in methanolic solutions, but inhibited highly this oxidation in the reversed micellar solutions. This enhancement of the furan oxidation was considered to be brought about by the occurrence of a radical mechanism (Type I) besides Type II mechanism. No Type I reaction occurred in the micellar solutions. The rate constants concerning with both reaction processes were evaluated by kinetic analysis, employing various aryl-and alkyl-amines. The reaction mechanism of Type I and the quenching mechanism of singlet oxygen by amines were discussed from the relationship between the rate constants, and the ionization potential of amines and the solvent polarity.

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