scholarly journals Singlet Oxygen Production Photosensitized by Fluorescein in Reversed Micellar Solutions

1980 ◽  
Vol 35 (6) ◽  
pp. 731-735 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Water Content ◽  
Reversed Micelles ◽  
Micellar Solutions ◽  
Oxygen Production ◽  
Fluorescence And Phosphorescence

Abstract The quantum yield of singlet oxygen production was investigated in dodecylammonium propionate reversed micellar solutions containing 1,3-diphenylisobenzofuran and fluo-rescein as photosensitizer. The quantum yield was highly enhanced by the binding of fluorescein to reversed micelles, and increased with decreasing the solubilized water content in reversed micelles. Results obtained was discussed with the optical properties of fluorescein (absorption, fluorescence and phosphorescence) in reversed micellar solutions.

scholarly journals Production and Reaction of Singlet Oxygen in Aqueous Micellar Solutions Using Pyrene as Photosensitizer

1978 ◽  
Vol 33 (6) ◽  
pp. 622-627 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Rate Constant ◽  
Oxidation Reaction ◽  
Sodium Dodecyl ◽  
Trimethylammonium Chloride ◽  
Micellar Solutions ◽  
Oxygen Production ◽  
Aqueous Micellar Solutions ◽  
Penetration Probability

Abstract The reaction of singlet oxygen with 1,3-diphenylisobenzofuran was investigated in aqueous micellar solutions of sodium dodecyl sulfate and dodecyl trimethylammonium chloride using pyrene as photosensitizer. Singlet oxygen, produced by the photosensitization of pyrene bound to micelles, oxidized efficiently 1,3-diphenylisobenzofuran bound to micelles. The quantum yield for singlet oxygen production and the rate constant for furan oxidation were determined by the kinetic analysis for the oxidation reaction of furan. Quenching of singlet oxygen by sodium azide competed with the furan oxidation, and its rate constant was also determined. Results obtained were compared with those in methanolic solutions. The quantum yield for singlet oxygen production and the rate constant for furan oxidation were much higher in micellar solutions than those in methanolic solutions. Empty micelles wxas found to act as a considerably strong scavenger for singlet oxygen. The penetration probability of singlet oxygen from aqueous phase into the interior of micelles which bound furan was also estimated

Solubilization and Photoreaction of Thiazine Dyes in Reversed Micelles

1980 ◽  
Vol 35 (11) ◽  
pp. 1444-1448 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Absorption Band ◽  
Singlet Oxygen ◽  
Reversed Micelles ◽  
Quantum Yields ◽  
Micellar Solutions ◽  
Oxygen Production ◽  
Relative Quantum ◽  
Thiazine Dyes ◽  
Monomer Band

AbstractThiazine dyes were solubilized very slowly in dodecylammonium propionate reversed micellar cyclohexanic solutions containing 0.5 M H2O. Light accelerated highly the solubilization of the dyes. The dye monomer band blue-or red-shifted by the solubilization dependent on the dye species. Thiazine dyes solubilized in the reversed micelles containing 0.1 M H2O exhibited a new absorption band at about 500 nm. The photoreduction of thiazine dyes by allylthiourea was enhanced drastically by solubilizing the dyes in the reversed micellar solutions containing 0.5 M H2O, and the singlet oxygen production was also effectively photosensitized by the solubilized thiazine dyes. The relative quantum yields for the photoreduction of the dyes by allylthiourea and the furan oxidation by singlet oxygen produced by the photosensitization of the dyes were obtained in the reversed micellar solutions. Results obtained were discussed in connection with the solubilization.

Buffer Action of Reversed Micelles

1980 ◽  
Vol 35 (6) ◽  
pp. 736-740 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Optical Properties ◽  
Initial Rate ◽  
Ph Value ◽  
Reversed Micelles ◽  
Fluorescein Sodium ◽  
Micellar Solutions ◽  
Excited Singlet ◽  
Buffer Action ◽  
Singlet States ◽  
Excited Singlet States

Abstract The optical properties (absorption and fluorescence) of fluorescein sodium were investi-gated with changing the bulk pH value in aqueous, water-methanol mixed and dodecyl-ammonium propionate reversed micellar solutions. A strong buffer action was found in the reversed micellar solutions. The pKa values for the equilibrium between fluorescein mono-and di-anions in the ground and excited singlet states highly decreased in the reversed micellar solutions compared with those in non-micellar solutions. The micellar buffer action strongly affected the initial rate of the 1,3-diphenylisobenzofuran oxidation caused by the photosensitization of fluorescein. The buffer action was closely related to the solubilized water content.

scholarly journals Tritolylporphyrin dimer as a new potent hydrophobic sensitizer for photodynamic therapy of melanoma.

2001 ◽  
Vol 48 (1) ◽  
pp. 277-282 ◽  
Author(s):  
A Drzewiecka ◽  
K Urbańska ◽  
Z Matuszak ◽  
M Pineiro ◽  
L G Arnaut ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Biological Effect ◽  
Photophysical Properties ◽  
Red Light ◽  
Human Melanoma ◽  
Oxygen Production ◽  
Absorption And Emission ◽  
Emission Properties

We report the synthesis, photochemical and photophysical properties and preliminary studies on biological effect of a new tritolylporphyrin dimer (T-D). Absorption and emission properties of T-D suggest its possible use in photodynamic therapy. T-D is capable of singlet oxygen production with 0.8 quantum yield. It also has a high photostability. The photodynamic properties of the dimer were examined following the growth of SKMEL 188 (human melanoma) cells irradiated with red light (cut off < 630 nm). The surviving fraction of the cells decreased about 3-fold (vs. non-irradiated cells) for an 81 J/cm dose. Our results suggest that tritolylporphyrine dimer T-D may be an interesting hydrophobic sensitizer for photodynamic therapy.

Sulfonated phthalocyanines: aggregation and singlet oxygen quantum yield in aqueous solutions

2003 ◽  
Vol 07 (03) ◽  
pp. 147-154 ◽  
Author(s):  
Nina A. Kuznetsova ◽  
Nataliya S. Gretsova ◽  
Valentina M. Derkacheva ◽  
Oleg L. Kaliya ◽  
Evgeny A. Lukyanets
Keyword(s):  
Quantum Yield ◽  
Aqueous Solutions ◽  
Singlet Oxygen ◽  
Central Atom ◽  
Photochemical Activity ◽  
Oxygen Production ◽  
Sulfonation Degree ◽  
Monomer Fraction ◽  
Sulfonated Phthalocyanines ◽  
Steric Hindrances

The influence of sulfonation degree (n) and central atom nature on singlet oxygen quantum yield (ΦΔ) were studied for a series of sulfonated phthalocyanine metal complexes MPcS n mix . It was found that in DMSO, where the studied dyes exist as monomers, ΦΔ values are independent of number and position of the sulfogroups and are equal to 0.11 ± 0.02, 0.19 ± 0.03, 0.37 ± 0.05, 0.38 ± 0.05 and 0.68 ± 0.10 for the metal-free and Mg , Gd , Al and Zn complexes, correspondingly. However, in aqueous solutions, aggregation of the dyes determines their photochemical activity. Substitution in adjacent to macrocycle 3 and 6 benzene positions interferes with aggregation compared to 4 and 5 positions, presumably due to enhanced steric hindrances in the former case. In the ZnPcS n mix series (n varied from 2 to 4), as an example, the linear relationship between degree of aggregation and ΦΔ indicates that only the monomer fraction of the dye is responsible for singlet oxygen production. For less sulfonated samples the order of activity of the dyes in water is as follows: H 2 PcS n mix < M II PcS n mix < M III PcS n mix which is in contrast to their tendencies to form aggregates.

Quenching of Singlet Oxygen by Sodium Azide in Reversed Micellar Systems

1979 ◽  
Vol 34 (2) ◽  
pp. 339-343 ◽  
Author(s):  
Norio Miyoshi ◽  
Giiti Tomita
Keyword(s):  
Singlet Oxygen ◽  
Heavy Atom ◽  
Reversed Micelles ◽  
Micellar Solutions ◽  
Oxygen Quenching ◽  
Singlet Oxygen Quenching ◽  
Micellar Systems ◽  
Azide Ion ◽  
State Of Water ◽  
Atom Effect

Abstract The oxidation reaction of singlet oxygen with 1,3-diphenylisobenzofuran was investigated in cyclohexanic reversed micellar solutions of dodecylammonium propionate, using pyrene as photosensitizer. The furan oxidation was effectively inhibited by azide ion-bound reversed micelles. Empty reversed micelles also inhibited the furan oxidation to some extent. The inhibition of the furan oxidation was due to the quenching of singlet oxygen by azide ion-bound and empty reversed micelles. Such singlet oxygen quenching was dependent on the concentration of water added.Results obtained were discussed in connection with the polarity in the interior of reversed micelles, micellar size, the state of water solubilized in reversed micelles and the lifetime of singlet oxygen. The heavy atom effect on the quenching of singlet oxygen was also studied using heavy water.

Sign in / Sign up

Export Citation Format

Share Document