The Mechanism of Photo-Fries Fragmentation of Aryl Cinnamates in Polymer Films and in Solution
Chemistry and Biochemistry
The photo-Fries rearrangement has been observed for the aryl cinnamate chromophore in both polyaryl cinnamates and small-molecule models. Laser flash photolysis of solutions of aryl cinnamates and the corresponding polymers leads to phenoxy and cinnamoyl radicals from the cleavage of the C-O ester bond. The formation of these radicals has been verified by their independent generation by flash photolysis of phenols (e.g. p-pentyloxyphenol) and aldehydes (e.g. p-methoxycinnamaldehyde). The effects of triplet sensitizers and quenchers on the formation of these transient intermediates and on the formation of the photo-Fries rearrangement products are reported. It is concluded that these products arise from either the aryl cinnamate singlet state or a short-lived upper triplet state.
Journal of Photochemistry and Photobiology A: Chemistry
Hoyle, C. E.,
(1991). The Mechanism of Photo-Fries Fragmentation of Aryl Cinnamates in Polymer Films and in Solution. Journal of Photochemistry and Photobiology A: Chemistry, 61(3), 317-327.
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