Sensitizer of Allylthiourea Photooxygenation

Chlorophyll has been shown to be a sensitizer for type II photooxygenation reactions of various substrates.61135 A quantitative study has been made with allylthiourea as a substrate by Livingston and Owens.86 

Therefore, the reaction constant evaluated from the variation of f ao2 with the concentration of allylthiourea has been taken as kejk9 + Au[S]/fc9. However, no experiments with different chlorophyll concentrations have been reported in order to show the dependence of this constant on [S]. 

According to Table VI, the quantum yield of allylthiourea oxygenation, 4ao2, exceeds the quantum yield of triplet chlorophyll formation, 

TABLE VI Spectroscopic Data, Quantum Yields, and Rate Constants Chlorophyll a in Methanol at 20°C (from ref. 86)  

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