✦ LIBER ✦
Two-photon processes in ketone photochemistry observed by time-resolved ESR spectroscopy
✍ Scribed by F. Jent; H. Paul; H. Fischer
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 432 KB
- Volume
- 146
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Laser flash excitation of the photopolymerization initiator o,w-dimethoxyw-phenylacetophenone at 308 nm in toluene yields benzoyl and a,a-dimethoxybenzyl radicals. The latter fragment on absorption of a second photon to methylbenzoate and methyl radicals. This explains previous contradictory results on the photochemistry of the system. Further, excitation of triplet acetone yields a-cleavage even in 2-propanol solution, where photoreduction of normal triplets is fast. The advantages of directly detected ESR to study such two-photon processes are discussed.