ESR study of irradiated single crystals of the cocrystalline complex of cytidine: Salicylic acid

Journal Article · Thu Dec 01 04:00:00 EST 1983 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.445691· OSTI ID:5554887

Close, D M; Sagstuen, E

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), Journal Name: J. Chem. Phys.; (United States) Vol. 79:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
AZINES
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
CRYSTALS
CYTIDINE
DECOMPOSITION
ELECTRON SPIN RESONANCE
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
MAGNETIC RESONANCE
MONOCRYSTALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOXY RADICALS
PYRIMIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
RESONANCE
RIBOSIDES
SALICYLIC ACID