Chemistry of singlet oxygen III. Product selectivity

Studies on Photochemical Reactions of Air Pollutants. XV. Photoreactivity of Heptachloro-3'-cyclopentenyldioxy Heptachloro-2-cyclopentene Formed by Exposure of Hexachlorocyclopentadiene to Ultraviolet Light in Air

“…That is to say, light transmitted through the 400 nm cut-off filter did not excite 1. Then, we examined whether or not 2 is produced when the ground state of 1 is brought into contact with singlet oxygen ( 1 D g ) generated by the reaction of hypochlorite with hydrogen peroxide, [16][17][18][19][20][21][22][23][24] because it has already been reported that cyclopentadiene derivatives and singlet oxygen ( 1 D g ) undergo adduct formation. [25][26][27][28][29][30] However, no reaction was observed.…”

Reactions of singlet oxygen. Part V. Dye sensitized photooxidation of m-hydroxydiphenylamine

“…which is obviously for high HDPA concentration where the role of the singlet oxygen is negligible. Equation [19] predicts a direct linear relationship between rate and oxygen concentration at constant amine concentration (as observed) if k12[302] is neglected in comparison to k,,; this is reasonable because step [17] involves back electron transfer from dye to amine and is known to be an efficient process (8). It is, therefore, apparent that at high concentrations of HDPA triplet dye is interacting with the substrate and singlet oxygen is not being formed.…”

“…Limonene gives rise to the same product distribuDye sensitized photooxidation of mono-, di-, and tion and kinetic features in both sensitized phototri-n-butylamines has been suggested to take place oxidation and chemically produced singlet oxygen without the participation of singlet oxygen (16). oxidations (17). But Bartholomew and Davidson The dye sensitization reaction in the flash photol-have pointed out that there is a competition beysis of amines has been observed not to involve tween the two primary processes viz.…”

Reactivities and Products in Photosensitized Oxidation of Unsaturated Triglycerides

“…It has been known that ML monohydroperoxides produced by singlet oxygen during the photooxidation consist of both conjugated and nonconjugated isomers. L4 ) Singlet oxygen is therefore assumed to react with each acyl group of the unsaturated TG, and its olefinic bond probably shifts to an adjacent position by a mechanism of a six membered ring transition state 12 ) or perepoxide intermediate. 13 ) TLDHP and TLTHP seem to be produced by the binding of singlet oxygen to non-oxygenated acyl group of TLMHP.…”