Determination of radiation damage in gluconolactone and N-allylthiourea single crystals by EPR spectroscopy

This thesis covers EPR (Electron Paramagnetic Resonance) measurements performed on N-allylthiourea (C₄H₈N₂S) and gluconolactone (C₆H₁₀O₆) powder samples. The samples were converted into single crystals by slow evaporation method in laboratory environment by preparing solutions with suitable solvents. The obtained crystals were irradiated with rays and EPR spectra were recorded. It was decided that a vinyl radical was formed when N-allylthiourea single crystal was irradiated with rays. It was determined that the hyperfine structure constant was determined as a_vinil=14,26 G and the spectroscopic splitting factor as g_av=2,002716 for the N-allylthiourea vinyl radical. When gluconolactone was irradiated with rays, an anion radical was formed. The spectroscopic splitting factor and hyperfine structure constants for gluconolactone anion radical were found to be g_av=2,004881, a_((CH)_β )=23,62 G,〖 a〗_((CHOH)_γ )=6,85 G , respectively. The spectroscopic splitting and hyperfine structure constants of both radicals show angular anisotropic properties. Hyperfine structure interaction tensors and g-tensors of all radicals exhibiting anisotropic interactions were calculated by the least squares method. The direction cosines of these tensors were determined by a special computer software. The obtained results are consistent with the literature and this study provides important data on the characterization of paramagnetic materials. Key Words: EPR, ESR, free radical, hyperfine coupling constant, spectroscopic splitting factor