ESR of a nitroxide radical and radical pair species in irradiated 3-hydroxyxanthine single crystals

Journal Article · Mon May 01 04:00:00 EDT 1978 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574886· OSTI ID:6880532

Jahan, M S; Alexander, C Jr

Single-crystal samples of the carcinogenic purine-N-oxide, 3-hydroxyxanthine hydrochloride, have been irradiated with ultraviolet (uv) light and studied by ESR techniques at room temperature. One radical species was detected with g-factor principal values of 2.0105, 2.0010, and 2.0050 and nitrogen hyperfine tensor elements of 14.2, 1.2, and 2.9 G. These data are consistent with the interpretation that a hydrogen atom has been abstracted from the hydroxyl group in the molecule and a nitrogen-centered radical is formed. The unpaired spin density on N/sub 3/ was found to be 0.24. This radical was also formed when the sample was uv-irradiated at 77 K. Pairwise trapped radical species have been observed in single-crystal samples of 3-hydroxyxanthine hydrochloride when they are irradiated by x rays or high-energy electrons. Two radical pair species, I and II, have been studied at 300 K. The ESR data of radical pairs I and II were characteristic of the interaction between two identical nitrogen-centered radicals. The dipole-dipole splitting constant, ..delta../sub 11/ of radical pairs I and II, was, respectively, 256.3 and 256.3 G, and the ..gamma../sub eff/ distance was 6.02 A for both pairs.

• Research Organization: Univ. of Alabama, University
• OSTI ID: 6880532
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 74:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560111* -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CHEMICAL RADIATION EFFECTS
CHEMISTRY
COMPARATIVE EVALUATIONS
CRYSTALS
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
HETEROCYCLIC COMPOUNDS
IRRADIATION
LOW TEMPERATURE
MAGNETIC RESONANCE
MONOCRYSTALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOINDUCTION
RESONANCE
ULTRAVIOLET RADIATION
XANTHINES