EPR Study of Gamma-Irradiated Single Crystal 4-Phenylsemicarbazide
Yükleniyor...
Dosyalar
Tarih
2010
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Pergamon-Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Single crystals of 4-phenylsemicarbazide (4PSC) were investigated using an electron paramagnetic resonance (EPR) technique, with gamma irradiation of the crystals at different orientations in the magnetic field between temperatures of 120 and 450 K, and the spectra were found to be temperature independent. Taking into consideration the chemical structure and the experimental spectra of the irradiated single crystal 4PSC, we assumed that one or more paramagnetic species were produced, each having an unpaired electron delocalized in the phenyl ring. Pursuant to this assumption, six possible radicals were modeled using the B3LYP/6-311+G(d) level of density-functional theory. EPR parameters were calculated for these modeled radicals using the B3LYP method and TZVP basis set. The calculated hyperfine coupling constants were used as starting points for simulations. The experimental and simulated spectra for each of the three crystallographic axes were well matched for the modeled radical R6. We thus identified the R6 (C6H5NH) radical as a paramagnetic species produced in 4PSC. The experimental g-factor and hyperfine coupling constants of the C6H5NH radical were found to be anisotropic, with the average values g = 2.00431, a(NH)(N(8)) = 8.85 G, a(NH)(H(9)) = 16.85 G, a(o,p)(H(14,16,20)) = 6.47 G, and a(m)(H(18,19)) = 2.80 G.
Açıklama
Anahtar Kelimeler
EPR, g-factor, Isotropic hyperfine coupling constant, DFT calculations, 4-phenylsemicarbazide (4PSC)
Kaynak
Radiation Physics and Chemistry
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
79
Sayı
Künye
Sayın, U., Türkkan, E., Dereli, Ö., Yüksel, H., Birey, M., (2010). EPR Study of Gamma-Irradiated Single Crystal 4-Phenylsemicarbazide. Radiation Physics and Chemistry, (79), 863-869. Doi: 10.1016/j.radphyschem.2010.03.016
