EPR studied of gamma irradiated free radicals of imino and amino acid derivatives

EPR STUDIED OF GAMMA IRRADIATED FREE RADICALS OF IMINO ANDAMINO ACID DERIVATIVESAuthor: Murat AYDINSUMMARYThis work consists of two parts. In the first part, gamma irradiated amino acidderivatives of L-glutamine hydrochloride and N-carbamyl-L-glutamic acid singlecrystals were investigated by EPR. The radiation damage centers were attributed to the..C H (π electron radical) and ΝH2 (σ electron radical). It was seen from EPR spectra..that the EPR lines of C H and ΝH2 radicals are observed in the same values ofmagnetic field. The radiation damage center that occurred in the second sample wasattributed to the HOOCCH2CH2 (NHCONH2)COOH radical. The spectra wereindependent from orientation of magnetic field and consist of two lines. The hyperfinecoupling constant and g factors of radicals were determined.In the second part, gamma irradiated iminodiacetic acid derivatives ofiminodiacetic acid, iminodiacetic acid hydrobromide, iminodiacetic acid hydrochlorideand N-hydroxyethyl iminodiacetic acid single crystals were investigated. The evaluationof spectra in together with simulation program show their HN HCH2(COOH)2,H2N HCH2(COOH)2·Br, H2N HCH2(COOH)2·Cl, HOCH2CH2N HCH2(COOH)2radicals form respectively. Protons of CH and CH2 group of HN HCH2(COOH)2 andH2N HCH2(COOH)2·Br radicals were found to be magnetically equivalent andhyperfine coupling constant was found to be anisotropic. Hyperfine coupling constantsof α protons of other two radicals were found to be anisotropic.Irradiated radicals of iminodiacetic acid derivatives are the results ofwithdrawing the hydrogen atom from Cα atom which is attached to the carboxyl groupand nitrogen atom.KEYWORDS: EPR, Gamma Irradiation, Free Radicals, Amino Acid, minodiaceticAcid.