Photosensitized formation of peroxyl radicals in aqueous solutions of adenine at 77 K
Tóm tắt
Conditions for the formation of peroxyl radicals photosensitized by near-UV irradiation in frozen aqueous solutions of adenine containing 0.1 M NaCl (pH 4–7) are studied. Analysis of the EPR spectra shows that the systems under study contain two types of peroxyl radicals presumably classified earlier as O
2
−·
and HO
2·
·
. The effect of freezing methods on the production of the radicals is shown. The signal from O
2
−·
predominates in the spectra of samples with open surfaces and is likely due to the reduction of adsorbed O2 molecules with photoejected electrons. The signal from HO
2
·
could be due to photoinduced interaction between the sensitizer and solvent. Possible mechanisms of these processes are considered.
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