ESR of x-irradiated single crystals of 3'-cytidylic acid: hydrogen abstraction from C/sub 5'/ of the sugar moiety

Journal Article · Thu Apr 01 04:00:00 EST 1976 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574352· OSTI ID:7345475

Bernhard, W A ^[1]; Corelli, J C

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1. Univ. of Rochester School of Medicine and Dentistry, NY

The dominant free radical trapped in x-irradiated single crystals of 3'-cytidylic acid at 77/sup 0/K was identified as HOC/sub 5'/(H)C/sub 4'/(H) <. For this radical the g-tensor and hyperfine coupling tensors for the ..cap alpha..-hydrogen and two ..beta..-hydrogens were determined. An unusually large isotropic coupling (21 G) to the hydroxyl hydrogen is observed as a result of the O-H bond being constrained so as to give a very small torsion angle with the lone electron p-orbital axis. Crystals grown from D/sub 2/O give a collapsed spectrum where the hydroxyl splitting is reduced by a factor of 1/6.5. On warming to approximately 290/sup 0/K the HOC/sub 5'/(H)C/sub 4'/(H) < radical deprotonates yielding the primary room temperature radical -OC/sub 5'/(H)C/sub 4'/(H) <. A reorientation of approximately 40/sup 0/ is postulated to account for the observed directions of the hyperfine and g-tensor axes determined for the room-temperature radical.

• OSTI ID: 7345475
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 66:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CRYOGENIC FLUIDS
CRYSTALS
CYTIDYLIC ACID
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
ELEMENTS
FLUIDS
HYDROGEN
IONIZING RADIATIONS
LOW TEMPERATURE
MAGNETIC RESONANCE
MONOCRYSTALS
NONMETALS
NUCLEOTIDES
ORGANIC COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOLYSIS
REMOVAL
RESONANCE
X RADIATION