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The Reaction of Singlet Oxygen with Adamantylideneadamantane Mediated by Rose Bengal
Author(s) -
Jefford Charles W.,
Estrada Manuel Jimenez,
Barchietto Giacomo,
Berclaz Théo,
Geoffroy Michel
Publication year - 1990
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19900730610
Subject(s) - chemistry , singlet oxygen , rose bengal , dioxetane , epoxide , photochemistry , superoxide , methylene blue , oxygen , singlet state , medicinal chemistry , adduct , yield (engineering) , organic chemistry , catalysis , chemiluminescence , photocatalysis , physics , materials science , nuclear physics , metallurgy , excited state , enzyme
The photo‐oxygenation of adamantylideneadamantane ( 1 ) on siliceous supports using admixed granules of ion‐exchange resin fixed to methylene blue (MB) and rose bengal (RB) gave exclusively the corresponding dioxetane derivative 2 for the former sensitizer, while the latter gave 2 and traces of the epoxide 3. RB and the charge‐transfer complex produced from N ‐ethylcarbazole and 2,4,5,6‐tetranitrofluoren‐9‐one both reacted with chemically generated singlet oxygen to give superoxide radical anion. Trapping of the latter with 5,5‐dimethyl‐1‐pyrroline 1‐oxide gave an adduct exhibiting a characteristic ESR spectrum. The treatment of 1 in MeOH with 30% aqueous H 2 O 2 for 22 h at 60° gave 3 in 100% yield. Repetition of this experiment in the presence of 2,6‐di( tert ‐butyl)‐ p ‐cresol caused no significant change. These results indicate that singlet oxygen reacts with 1 , in the presence of RB, by two different processes. The first leads to dioxetane formation. The second process involves conversion of singlet oxygen by RB to superoxide radical anion which subsequently gives H 2 O 2 so producing epoxide 3 from 1 .