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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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    Electron paramagnetic resonance of gamma-irradiated single crystals of ethan-1,2 disulfonic acid disodium
    (ELSEVIER SCIENCE BV, 2012) Karatas, Ozgul; Aras, Erdal
    ESR spectra of ethan-1,2 disulfonic acid disodium (C2H4Na2O6S2) irradiated by Co-60-gamma were recorded between 125 K and 300 K and for different orientations of the crystal in the magnetic field. The spectra were found to be temperature independent. In C2H4Na2O6S2 single crystal, the radiation damage centers caused by a Co-60-gamma source were determined as SO2 radical. For SO2 radical, a value of spectroscopic splitting factor g was calculated. (C) 2012 Elsevier B.V. All rights reserved.
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    Electron paramagnetic resonance study of gamma (gamma)-irradiated methyl 4-methyl benzoate (C9H10O2)
    (TAYLOR & FRANCIS LTD, 2016) Karatas, Ozgul; Aras, Erdal; Karadag, A. Halide; Islek, Yasemin
    In this study, gamma ()-irradiated methyl 4-methyl benzoate (C9H10O2) single crystals were investigated and the structure of the free radical occurring by -irradiation was determined by using Electron paramagnetic resonance (EPR) technique. C9H10O2 single crystals were produced by slow evaporation with distilled water solution at room temperature. These single crystals were irradiated by Co-60-gamma-ray source with a dose speed of 0.981kGy/h at room temperature for 72h. The EPR spectra of irradiated C9H10O2 single crystals were recorded between 125 and 400K temperatures in steps of 10 degrees intervals at different orientations in magnetic field with an X-band EPR spectrometer. The spectra were found to be slightly anisotropic and temperature independent; taking into consideration the chemical structure with experimental data we found only one free radical structure The radical structure was simulated using the Bruker software WinEPR-Simfonia and the experimental g-value with anisotropic hyperfine coupling constants of radical were calculated as follows: g = 2.0124, aCH(4) = 26.51G, aCH(3) = 5.45G.
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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 METHYL-4-NITROBENZOATE SINGLE CRYSTALS
    (KAUNAS UNIV TECHNOLOGY PRESS, 2012) Aras, Erdal; Kilic, Ahmet; Cicek, Ekrem; Meric, Yasemin; Karatas, Ozgul; Grigonis, A
    Single crystals of methyl-4-nitrobenzoate C8H7NO4 have been observed and analyzed for different orientations of the crystal in the magnetic field, after being damaged at 300K by Co-60 gamma-irradiation by using Electron Paramagnetic Resonance (EPR) technique. The EPR spectrums of crystals have been taken with X-band EPR spectrometer at 150K temperature range. In C8H7NO4 single crystal, the radiation damage centers were determined to radical. For this free radical, anisotropic hyperfine splitting constants (A) and g-factors were calculated.