Photochemical singlet oxygenation

Industrial Prospects for the Chemical and Photochemical Singlet Oxygenation of Organic Compounds... 

I 22 Industrial Prospects for Chemical and Photochemical Singlet Oxygenation... 

Using a single-channel chip micro reactor, singlet oxygen is generated by photochemical means in presence of catalytic amounts of Rose Bengal [21]. By [4 -i- 2] cycloaddition of this oxygen species to a-terpinene, the product ascaridole is obtained. 

Photochemical irradiation of dimethyl and diethyl sulphoxides yields the corresponding sulphone in the presence of air and a photosensitizer such as methylene blue in yields up to 99% . Sulphoxides are also oxidized when they act as traps for persulphoxides, the intermediate formed on reaction of a sulphide with photochemically generated singlet oxygen - , equation (9). Isotope studies have shown that such reactions proceed through a linear sulphurane intermediate . Persulphones also react with sulphoxides in a similar manner , equation (10). 

Delmelle, M. (1978). Generation of singlet oxygen by the retina. Photochem. Pathobiol. 27, 731-734. 

Nevertheless, in the sensor study of heterogeneous reactions of singlet oxygen, it is better to employ selective sources that do not generate other active particles and produce though low, but stable concentrations of 02( ). These sources can be photochemical and chemical... 

Farmillo, A. and F. Wilkinson. 1973. On the mechanism of quenching of singlet oxygen in solution. Photochem. Photobiol. 18 447-450. 

Montenegro, M. A., M. A. Nazareno, E. N. Durantini et al. 2002. Singlet oxygen quenching ability of carotenoids in a reverse micelle membrane mimetic system. Photochem. Photobiol. 75 353-362. 

Rodgers, M.A.J. and Bates A.L. 1980. Kinetic and spectroscopic features of some carotenoid triplet states Sensitization by singlet oxygen. Photochem. Photobiol. 31 533-537. 

El-Agamey, A, Cantrell, A, Land, EJ, McGarvey, DJ, and Truscott, TG, 2004a. Are dietary carotenoids beneficial Reactions of carotenoids with oxy-radicals and singlet oxygen. Photochem Photobiol Sci 3, 802-811. 

Redmond, RW and Kochevar, IE, 2006. Spatially resolved cellular responses to singlet oxygen. Photochem Photobiol 82, 1178-1186. 

Bohm, F, R Edge, M Burke, and TG Truscott. 2001. Dietary uptake of lycopene protects human cells from singlet oxygen and ntirogen dioxide—ROS components from cigarette smoke. J Photochem Photobiol B 64 176-178. 

Conn, P.F., Schalch, W., and Truscott, T.G. 1991. The singlet oxygen and carotenoid interaction. Photochem Photobiol 11B41-47. 

Surface water computed t,/2 = 0.13 h at near-surface of a water body, for direct photochemical transformation, and t,/2 = 0.79 d for direct photolysis in a 5-m deep inland water body with no sediment-water partitioning, t,/2 = 1.2 d with sediment-water partitioning to top cm bottom sediment and t,/2 = 10 h for photosensitized oxygenation with singlet oxygen at near-surface natural water, 40°N, midday, midsummer (Zepp Schlotzhauer 1979) ... 

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