EPR studies of the structure of transient radicals formed in photolytic reactions of some 2-nitrobenzyl compounds. Characterisation of aryl alkoxy aminoxyls and nitroaromatic radical-anions in the photolysis of caged ATP and related compounds
2000; Issue: 12 Linguagem: Inglês
10.1039/b005073n
ISSN2050-8247
AutoresJohn E. T. Corrie, Bruce C. Gilbert, V. Ranjit N. Munasinghe, Adrian C. Whitwood,
Tópico(s)Photochemistry and Electron Transfer Studies
ResumoRadical species generated on photolysis of 2-nitrobenzyl compounds, including derivatives of 1-(2-nitrophenyl)ethyl phosphate (caged ATP 1 and caged monomethyl phosphate 3) have been studied by EPR spectroscopy and their identity confirmed by independent chemical generation of the appropriate nitrogen-centred radicals. The reactions which occur include photo-isomerisation, photo-fragmentation, photo-assisted electron-transfer, intramolecular addition and spin-trapping reactions of the nitroso compounds produced via molecular rearrangement. In particular, a mechanistic scheme is advanced to explain the co-formation of a radical-anion and a cyclic aryl alkoxy aminoxyl (2 and 30, respectively, from caged ATP). Which of these species is observed in the EPR spectrum depends upon the particular experimental conditions.
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