Original scientific paper
Fine phenomena in the EPR spectra of the hole-like paramagnetic centre in cytosine hydrochloride
Dubravka Krilov
; School of Medicine and cFaculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
Krešimir Sanković
; School of Medicine, University of Rijeka, Rijeka, Croatia
Tatjana Pranjić-Petrović
; School of Medicine, University of Rijeka, Rijeka, Croatia
Janko N. Herak
; Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
Abstract
The fine phenomena in the EPR spectra of the hole-like paramagnetic centre formed in cytosine(thiocytosine)-HCl crystals upon irradiation are studied with EPR spectroscopy. The spin Hamiltonian including the electronic Zeeman term, hyperfine coupling, quadrupole coupling and the nuclear Zeeman term has been used in the second-order perturbation treatment for the interpretation of the experimental observations. It is shown that the quadrupolar term causes a detectable shift of the EPR lines and also induces the "forbidden'' transitions. From the shift of the "allowed'' transitions and the positions of the ``forbidden'' transitions, the chlorine quadrupolar coupling tensor [P], has been determined.
Keywords
Hrčak ID:
299573
URI
Publication date:
1.9.1995.
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