Izvorni znanstveni članak
EPR spectroscopy of 5-YL radicals in gamma-irradiated single crystals of 2-thiothymine
E. Bešić
; Department of Biophysics, Faculty of Pharmacy and Biochemistry, University of Zagreb, A. Kovačića 1, 10002 Zagreb, Croatia
J. N. Herak
; Department of Biophysics, Faculty of Pharmacy and Biochemistry, University of Zagreb, A. Kovačića 1, 10002 Zagreb, Croatia
Sažetak
Single crystals of 2-thiothymine (5-methyl-2-thiouracil) have been g-irradiated at 300 K and studied using EPR spectroscopy. The 5-thymil (5-yl) radical, formed by a net hydrogen-atom addition to the C(6) of 2-thiothymine base, has been studied in detail. The hyperfine tensors of methyl and methylene proton couplings are given together with the g-tensor. It has been shown that the calculated hyperfine proton couplings and relative orientation of the coupling tensors along the pyrimidine ring are similar to those observed earlier in 5-yl radicals in the single crystals of thymine and its derivatives. Although no large differences in the hyperfine couplings were found, calculated values of the g-tensor are appreciably larger in comparison to the other thymine-like systems, what is expected due to the presence of sulfur at C(2) in 2-thiothymine.
Ključne riječi
5-yl radicals; EPR spectroscopy; 2-thiothymine
Hrčak ID:
302511
URI
Datum izdavanja:
1.7.2007.
Posjeta: 158 *