197861-98-6Relevant articles and documents
Photochemical Reactions of Halo-/Aryl Sulfide-Substituted Alkyl Phenylglyoxylate, an Assessment of the Lifetime of the Intermediate 1,4-Biradical
Hu, Shengkui,Neckers, Douglas C.
, p. 7827 - 7831 (1997)
Photochemical reactions of several halo/aryl sulfide-substituted alkyl phenylglyoxylates (1) were studied. For 2′-bromo- (1b), 2′-iodo- (1c), 2′-(phenylthio)- (1d), and 2′-(phenylsulfinyl)- (1e) ethyl phenylglyoxylate, vinyl phenylglyoxylate (2), proposed to be the result of β-elimination from the 1,4-biradical formed by triplet state γ-hydrogen abstraction, is the dominant photoproduct. In the cases 1b and Id Norrish Type II products were also observed. Vinyl phenylglyoxylate (2) was not observed with 2′-chloroethyl (1a), 3′-bromopropyl (1f), and 3′-(phenylthio)propyl (1g) phenylglyoxylate. The lifetime of the 1,4-biradical intermediate is deduced from the competition between the β-elimination of the monoradical and the normal biradical decay. The triplet lifetime and the photoreaction efficiency of 1 were not significantly affected by halogen-substitution.
