부산대학교 도서관

Solid-state sucrose is a well-knowndosimetric system, which iscapable of reliable dose estimates only at a considerable time afterexposure. Immediately after irradiation at room temperature, its electronparamagnetic resonance (EPR) spectrum is dominated by contributionsfrom unstable radicals, which are studied here using continuous-waveEPR and electron–nuclear double resonance (ENDOR) spectroscopy.Four hyperfine tensors of proton couplings were determined, associatedwith two radical species, and subsequently compared to density functionaltheory calculation results, which led to the identification of thespecies with lower abundance (U2) as a radical formed by a H abstractionfrom C4. The more abundant center (U1) has not been definitively identifiedyet, but we present compelling evidence that it should be a C6 centeredradical. Comparison of the simulated EPR spectra with all availabledata to the experimental ones suggests that the EPR spectrum of X-irradiatedsucrose immediately after irradiation can now be almost entirely understood. [ABSTRACT FROM AUTHOR]