ESR study of irradiated single crystals of the cocrystalline complex of cytidine: Salicylic acid
Irradiation at 77 K of single crystals of the 1:1 complex of cytidine and salicylic acid produces a phenoxyl radical formed by oxidation of the salicylic acid. Anisotropic hyperfine coupling tensors have been determined for this radical which are associated with the para and ortho hydrogens. No cytidine oxidation products (alkoxy or hydroxyalkyl radicals) were observed at 77 K. Following the decay of the phenoxyl radical at room temperature, four radicals were detected. These include the cytosine 5--yl and 6--yl radicals, formed by H addition to the cytosine ring, and an anisotropic doublet. By UV irradiation at room temperature, it is possible to convert a significant fraction of 6-yl radicals into 5-yl radicals. Hyperfine coupling and g tensors determined for the anisotropic doublet indicate that this radical is formed in the C/sub 1'/-C/sub 2'/ region of the sugar moiety. These results indicate a shift in radiation damage away from the salicylic acid upon warming, and show that the radiation chemistry of the cocrystalline complex is different from that of the isolated bases.
- Research Organization:
- Department of Physics, East Tennessee State University, Johnson City, Tennessee 37614
- OSTI ID:
- 5554887
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 79:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CYTIDINE
RADIOLYSIS
SALICYLIC ACID
CHEMICAL RADIATION EFFECTS
COMPLEXES
ELECTRON SPIN RESONANCE
MONOCRYSTALS
PHENOXY RADICALS
AZINES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHEMISTRY
CRYSTALS
DECOMPOSITION
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
MAGNETIC RESONANCE
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RESONANCE
RIBOSIDES
400600* - Radiation Chemistry