EPR Studies on Trapped Species Produced in the Gamma Radiolysis of Aqueous Sugar Ices

• Published in: The Journal of chemical physics 1971-01, Vol.54 (7), p.2899-2909
• Main Authors: Zimbrick, J. D., Myers, L. S.
• Format: Article
• Language: English
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.1675270

The yields, EPR spectral characteristics, and paramagnetic relaxation of trapped electrons (eT−) and sugar radicals were studied in 60Co γ-irradiated monosaccharide ices at 77°K. The eT− yields in the various ices ranged from 0.95 to 1.8 and were strongly dependent on solute molarity and phase of the ice matrix. In most cases the sugar radical yields were the same as the eT− yields. The eT− could be bleached with white light to form dielectrons as previously found for eT− in alkaline ices. The EPR line shapes, linewidths, and line broadening mechanisms of eT− in the sugar ices were similar to the corresponding characteristics of eT− in alkaline ice. Spectral studies on the trapped sugar radicals indicated that two groups of radicals were present. The variation of the eT− and sugar radical relaxation times with radiation dose was studied in H2O and D2O matrices. The results for eT− were interpreted as indicating a spatially nonuniform distribution of this species; the spatial nonuniformity is not as great in the D2O matrix as in the H2O matrix. The results for the sugar radicals suggested that one group was distributed uniformly, whereas the other group was distributed nonuniformly to the same degree as the eT− distribution.