CIDEP studies of the photolysis of the lignin model compound α-guaiacoxylacetoveratrone: the role of triplet reactions in aqueous and hydroxylic solvents
- 1 March 1992
- journal article
- Published by Springer Nature in Research on Chemical Intermediates
- Vol. 17 (1) , 59-75
- https://doi.org/10.1163/156856792x00056
Abstract
Free radical reactions induced by the photolysis of the lignin model compound α-guaiacoxylacetoveratrone have been studied by conventional and time-resolved ESR spectroscopy. In the presence of efficient hydrogen donors such as aqueous and hydroxylic solvents the primary reaction involves photoreduction of the triplet phenacyl ether to form the ketyl radical followed by rapid cleavage to the phenacyl radical and guaiacol. Subsequent formation of polarized guaiacoxyl radicals is due to secondary photo-oxidation. The cleavage of the ketyl radical is retarded in basic media and accelerated in acetic acid. Minor reaction pathways involving excited singlets cannot be ruled out by the current CIDEP observations.Keywords
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