Radiation induced free radical formation in sulfur-substituted purines. 6-Mercaptopurine at 77 K
Single crystals of the sulfur-containing purine base derivative 6-mercaptopurine have been irradiated by 4.0 MeV electrons and studied by electron spin resonance techniques at 77 K. The two main resonances observed, R1 and R3, were analyzed and identified. The R1 resonance exhibited a large g-value variation. The g-tensor principal values are 2.173, 2.002, and 1.989, and the resonance is ascribed to a thiyl radical formed by the abstraction of a hydrogen atom from N7. The R3 resonance showed an almost isotropic 1:2:1 triplet hyperfine structure with a splitting value of 38.5 G. The g-tensor principal values are 2.0138, 2.0065, and 2.0020. This resonance is assigned to a radical formed by hydrogen addition at the C8 position. The radical identifications were arrived at by a combination of the ESR data and results from molecular orbital calculations.
- Research Organization:
- Institute of Physics, Department of Biophysics, University of Oslo, Blindern, Oslo 3, Norway
- OSTI ID:
- 6699194
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 69:7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC SULFUR COMPOUNDS
RADIOLYSIS
PURINES
ELECTRON BEAMS
ELECTRON SPIN RESONANCE
MEV RANGE 01-10
RADICALS
VERY LOW TEMPERATURE
BEAMS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ENERGY RANGE
HETEROCYCLIC COMPOUNDS
LEPTON BEAMS
MAGNETIC RESONANCE
MEV RANGE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLE BEAMS
RADIATION CHEMISTRY
RADIATION EFFECTS
RESONANCE
400600* - Radiation Chemistry