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    An electron paramagnetic resonance study on irradiated triphenylphosphinselenid single crystal
    (TAYLOR & FRANCIS LTD, 2014) Aras, Erdal; Karatas, Ozgul; Meric, Yasemin; Abbass, Hind Kh; Birey, Mehmet; Kilic, Ahmet
    The single crystals of triphenylphosphinselenid [C18H15PSe] were produced by slow evaporation of concentrated ethyl acetate solutions. These single crystals were exposed to Co-60 gamma (gamma) rays with a dose speed of 0.980kGy/h at the room temperature for 72h. The free radical over the sample was observed using electron paramagnetic resonance (EPR)-X band spectrometer. The EPR spectra were recorded between 120 and 400K. Furthermore, the sample irradiated was rotated in steps of 10 degrees and analyzed for different orientations of the crystal in the magnetic field. Only one radical structure was determined on the molecule. The hyperfine constants of the sample were found to be anisotropic. The average values of these constants and value of g were calculated as following: g=2.007656, a(Se)=37.47G, a(P)=27.44G, a(Ha)=17.28G, and a(Hb)=18.16G.
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    EPR study of gamma-irradiated cholesteryl methyl carbonate
    (ELSEVIER SCIENCE BV, 2014) Aras, Erdal; Islek, Yasemin; Karatas, Ozgul; Abbass, Hind Kh; Birey, Mehmet; Kilic, Ahmet
    The electron paramagnetic resonance (EPR) of gamma-irradiated single crystals of cholesteryl methyl carbonate (C29H48O3) has been studied for different orientations of the crystals in a magnetic field. EPR spectra of cholesteryl methyl carbonate (C29H48O3 irradiated by Co-60-gamma were recorded between 125 K and 300 K for different orientations of the crystal in the magnetic field. The spectra were found to be temperature independent. In C29H48O3 single crystal,. the radiation damage centers caused by a Co-60-gamma source were determined as CH3CH2CH radical. For CH3CH2CH radical, a value of spectroscopic splitting factor g was calculated and experimentally results were supported by simulation program (WinEPR). (C) 2014 Elsevier B.V. All rights reserved.
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    EPR study of gamma-irradiated N-hydroxysuccinimide
    (TAYLOR & FRANCIS LTD, 2008) Asik, Biray; Aras, Erdal; Birey, Mehmet; Eken, Mahmut
    The electron paramagnetic resonance of gamma-irradiated single crystal of N-hydroxysuccinimide has been studied for different orientations of the crystals in a magnetic field. The radicals produced by gamma-irradiation have been investigated between 150 and 300 K. The spectra were found to be temperature independent and radiation damage centers were attributed to [GRAPHICS] radicals.
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    EPR study of gamma-irradiated tetra-N-butylammonium iodide
    (TAYLOR & FRANCIS LTD, 2012) Merdan, Mehmet Ali; Asik, Biray; Birey, Mehmet; Aras, Erdal
    The electron paramagnetic resonance of gamma-irradiated single crystal of tetra-N-butylammonium iodide has been studied for different orientations of the crystals in a magnetic field. The radical produced by gamma irradiation has been investigated at 300 K. The spectra were found to be magnetic field dependent and radiation damage centers were attributed to the (C alpha H2C beta H2C gamma H2CH3) radical. The principal values of the hyperfine coupling tensor of the unpaired electron with these atoms and the principal values of the gtensor were determined and the hyperfine coupling constants were verified by computer simulation. The results were found to be in good agreement with the existing literature data and theoretical predictions.