Yazar "Baskan, M. Halim" seçeneğine göre listele

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    Electron paramagnetic resonance and FT-IR spectroscopic studies of DL-2-aminoadipic acid and ammonium acetate powders
    (Taylor & Francis Ltd, 2014) Baskan, M. Halim; Aydin, Murat; Canakci, Dilek; Osmanoglu, Semsettin
    Exposure of powder forms of DL-2-aminoadipic acid and ammonium acetate to gamma radiation results in the formation of free radicals detected by the electron paramagnetic resonance spectroscopy at room temperature. In these compounds, the observed paramagnetic species were attributed to the HOOCCH2CH2CH2CHCOOH and CH2COONH4 radicals, respectively. The g values and the hyperfine coupling constants of the unpaired electron with the environmental protons were determined for these two radicals. In work, the observed paramagnetic species were found to be stable at room temperature for more than two months. Also, these compounds were characterised by FT-IR and UV-VIS. Their thermal stabilities were determined by TGA and DTA measurements. Thermal analyses were shown to be unstable of the HOOCCH2CH2CH2CH(NH2)COOH and CH3COONH4 against thermo-oxidative decomposition.
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    Electron paramagnetic resonance and FT-IR spectroscopic studies of glycine anhydride and betaine hydrochloride
    (Taylor & Francis Ltd, 2015) Baskan, M. Halim; Kartal, Zeki; Aydin, Murat
    Gamma irradiated powders of glycine anhydride and betaine hydrochloride have been investigated at room temperature by electron paramagnetic resonance (EPR). In these compounds, the observed paramagnetic species were attributed to the R1 and R2 radicals, respectively. It was determined that the free electron interacted with environmental protons and N-14 nucleus in both radicals. The EPR spectra of gamma irradiated powder samples remained unchanged at room temperature for two weeks after irradiation. Also, the Fourier Transform Infrared (FT-IR), FT-Raman and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of glycine anhydride and betaine hydrochloride were identified by vibrational spectroscopies (FT-IR and FT-Raman).
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    Electron paramagnetic resonance characterization of gamma irradiation damage centers in powder of L-(+)-tartaric acid, N-acetyl-L-alanine and 1-methyl-L-histidine
    (Taylor & Francis Ltd, 2010) Baskan, M. Halim; Aydin, Murat; Osmanoglu, Semsettin; Topkaya, Ramazan
    The electron paramagnetic resonance (EPR) of -irradiated powders of l-(+)-tartaric acid, N-acetyl-l-alanine and 1-methyl-l-histidine were investigated at room temperature. Radiation damage centers are attributed to HOOCCH(OH)C(OH)COOH, CH3CHCOOH and -CH2CHCOOH radicals. The spectra were computer-simulated. Hyperfine structure constants and g-values were determined for these three radicals. The unirradiated samples showed no EPR signal. Some spectroscopic properties and suggestions concerning the possible structure of the radicals are discussed in this paper.
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    Electron paramagnetic resonance of some ?-irradiated amino acid derivatives
    (Walter De Gruyter Gmbh, 2006) Zincircioglu, S. Burhanedtin; Canoruc, Naime; Osmanoglu, Semsettin; Baskan, M. Halim; Dicle, I. Yesim; Aydin, Murat
    gamma-Irradiated powders of N-acetyl-L-arginine, N-alpha-carbamyl-L-arginine, N-glycyl-L-leucine and glycyl-L-alanine were investigated at room temperature by electron paramagnetic resonance. The observed species in N-acetyl-L-arginine and Na-carbamyl-L-arginine were attributed to the CH2CHNHCNHNH2 radical, and those in N-glycyl-L-leucine and glycyl-L-alanine powders to (CH3)(2)(CCH2 and CH3CHCOOH radicals.
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    Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride
    (Pergamon-Elsevier Science Ltd, 2013) Baskan, M. Halim; Aydin, Murat
    The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3CHCOOC2H5, -CH2CHCOOH and -CH2CHCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed. (c) 2013 Published by Elsevier B.V.
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    EPR and FT-IR spectroscopic studies of L-lysine monohydrochloride and L-glutamic acid hydrochloride powders
    (Elsevier, 2011) Aydin, Murat; Kartal, Zeki; Osmanoglu, Semsettin; Baskan, M. Halim; Topkaya, Ramazan
    Powders of L-lysine monohydrochloride and L-glutamic acid hydrochloride were gamma irradiated and the induced free radicals were investigated at room temperature by electron magnetic resonance techniques. The observed species in these compounds were attributed to the H(2)NCH(2)CH(2)CH(2)CH(2)CHGOOH and HOOCCH2CH2CHCOOH radicals, respectively. In both radicals, the unpaired electron interacted with alpha-proton and beta-protons. Also, the FT-IR and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of L-lysine monohydrochloride and L-glutamic acid hydrochloride were identified by FT-IR spectrometer. The TGA, DTA and DTG graphics were obtained to explain the thermal behavior of molecules. (C) 2011 Elsevier B.V. All rights reserved.
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    EPR Investigation of Gamma- Irradiated L-Proline and L-Serine
    (Gazi Univ, 2022) Baskan, M. Halim
    In this work, electron paramagnetic resonance (EPR) spectra of gamma irradited L-proline and L-serine powders have been examinated at 300 K, as well as to determine their stability and radical structures. The EPR of samples were attributed to the CH3CH and CH2CNH2 radicals. The EPR spectra were seen to be stable for more than five months. The results obtained from the radicals discussed here were observed to be in good agreement with the literature data.
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    EPR investigation of gamma-irradiated L-citrulline, ?-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine
    (Elsevier, 2017) Osmanoglu, Y. Emre; Sutcu, Kerem; Baskan, M. Halim
    The spectroscopic parameters of the paramagnetic species produced in gamma-irradiated L-citrulline, alpha-methyl-m-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine were investigated at room temperature at a dose of 20 kGy by using EPR technique. The paramagnetic species were attributed to NH2CONH(CH2)(3)CNH2COOH, HOCH2CCH3COOH and HOCHCCH3NH2COOH, CH3CH3CCHNH2COOH and SHCH(2)GNHCOCH(3)COOH radicals, respectively. EPR data of the unpaired electron with the environmental protons and N-14 nucleus were used to characterize the contributing radicals produced in gamma irradiated compounds. In this paper, the stability of these compounds at room temperature after irradiation was also studied. (C) 2016 Elsevier B.V. All rights reserved.
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    EPR of ?-irradiated L-glutamine, glycyl-L-glutamine and N-glycyl-L-valine
    (Taylor & Francis Ltd, 2008) Baskan, M. Halim
    gamma-irradiated powders of L-glutamine, glycyl-L-glutamine and N-glycyl-L-valine were investigated at room temperature and 150K by electron paramagnetic resonance (EPR). The spectra were found to be temperature independent. The g-values and hyperfine coupling constants of the unpaired electrons with the environmental protons and the N-14 nucleus were determined. The species were found to be stable at room temperature for more than six months. The unirradiated samples were found to display no EPR signal.
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    EPR of ?-irradiated single crystal of iminodiacetic acid
    (Taylor & Francis Ltd, 2008) Baskan, M. Halim; Aydin, Murat; Osmanoglu, Semsettin
    The electron paramagnetic resonance of gamma-irradiated single crystal of iminodiacetic acid, HN(CH2COOH)(2), has been observed and analyzed for different orientations of the crystal in the magnetic field. The radicals produced by gamma-irradiation have been investigated at room temperature. The radiation damage centers produced in the crystals were attributed to the HN<(C)over dot>HCH2(COOH)(2) radical. The g values and hyperfine coupling constants of the unpaired electron with the environmental alpha-proton, methylene protons, NH proton and N-14 nucleus were determined. The results were found to be in agreement with hyperfine coupling and are discussed.
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    EPR studies of gamma-irradiated L-alanine ethyl ester hydrochloride, L-arginine and alanyl-L-glutamine
    (Taylor & Francis Ltd, 2008) Aydin, Murat; Baskan, M. Halim; Yakar, Sedat; Ulak, F. Sadan; Aydinol, Mahmut; Aydinol, Belkis; Bueyuem, Muharrem
    gamma-Irradiated powders of L-alanine ethyl ester hydrochloride (LAES), L-arginine (LA) and alanyl L-glutamine (ALG) were investigated at room temperature by electron paramagnetic resonance (EPR). The observed species in LAES and LA are attributed to the CH3CHCOOC2H5 and CH2CHNHCNHNH2 radicals, respectively. In the case of ALG, the EPR signal is attributed to the CH2CNHCOOH. Hyperfine structure constants and g-values are determined for these three radicals. It is found that these results are in good agreement with those of previous experimental and theoretical studies. The unirradiated samples were found to display no EPR signal.
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    EPR Study of Gamma Induced Radicals in Amino and Iminodiacetic Acid Derivatives
    (Soc Brasileira Fisica, 2009) Aydin, Murat; Baskan, M. Halim; Osmanoglu, Y. Emre
    In this study, electron paramagnetic resonance spectroscopy was used to investigate free radicals formed in gamma irradiated L-glutamine hydrochloride, iminodiacetic acid hydrochloride and N-(2-hyroxyethyl) iminodiacetic acid powders. The free radicals produced in L-glutamine hydrochloride powders were attributed to the CH(2)(C) over bar HCOOH radical; and those in iminodiacetic acid hydrochloride and N-(2-hyroxyethyl) iminodiacetic acid powders to the HNCHCH(2)(COOH)(2) and HOCH(2)CH(2)N (C) over bar HCH(2)(COOH)(2), respectively. The g-values of the radicals and the hyperfine structure constants of the free electron with the environmental protons and (14)N nucleus were determined. The samples were not displayed before they were not irradiated. The free radicals were found stable at room temperature for more than six months. Some spectroscopic properties and suggestions concerning possible structure of the radicals are discussed in this paper.
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    Investigation of 60Co ?-irradiated L-(-) malic acid, N-methyl-DL-valine and L-glutamic acid ?-ethyl ester by electron paramagnetic resonance technique
    (Elsevier Science Bv, 2010) Baskan, M. Halim; Aydin, Murat; Osmanoglu, Semsettin
    The electron paramagnetic resonance spectra of gamma-irradiated L-(-) malic acid, N-methyl-DL-valine and L-glutamic acid gamma-ethyl ester powders have been investigation at room temperature. Radiation damage centres are attributed to HOOCCH2CHCOOH, (CH3)(2)CCH(NHCH3)COOH and C2H5OCOCH2CH2C(NH2)COOH radicals, respectively. The spectra have been computer simulated. The EPR parameters of the observed radicals have been determined and discussed. (C) 2010 Elsevier B.V. All rights reserved.
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    Radiation damage produced in powder of ?-(methylamino)isobutyric acid, ?-aminoisobutyric acid methyl ester hydrochloride and diethylmalonic acid
    (Taylor & Francis Ltd, 2009) Baskan, M. Halim; Osmanoglu, Semsettin; Dicle, I. Yesim
    The electron paramagnetic resonance spectra of gamma-irradiated powders of alpha-(methylamino) isobutyric acid - CH(3)NHC(CH(3))(2)COOH, alpha-aminoisobutyric acid methyl ester hydrochloride - NH(2)(CH(3))(2)CCOOCH(3) HCl, and diethylmalonic acid - (CH(3)CH(2))(2)C(COOH)(2) have been investigated at room temperature. It has been found that gamma-irradiation produces the (CH(3))(2)(C) over dotCOOH radical in the first, the (CH(3))(2)(C) over dotCOOCH(3) radical in the second and the (CH(3)CH(2))(2)(C) over dot COOH radical in the third compound. The spectra were computer-simulated. The g values and the hyperfine coupling constants of the unpaired electron with the environmental methyl, methylene protons and OH proton were determined. The results were found to be in good agreement with the existing literature data and theoretical predictions.
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    Radiation damage produced in single crystal of iminodiacetic acid hydrobromide
    (Elsevier, 2010) Aydin, Murat; Osmanoglu, Semsettin; Baskan, M. Halim; Dicle, I. Yesim
    Single crystals of iminodiacetic acid hydrobromide, H2N(CH2COOH)(2)center dot Br, were gamma-irradiated and the formed paramagnetic species were investigated at room temperature and analyzed for different orientations of the crystal in the magnetic field by electron paramagnetic resonance technique. The observed species in iminodiacetic acid hydrobromide single crystals were attributed to the H2NCHCH2(COOH)(2)center dot Br radical. The g values and hyperfine coupling constants of the unpaired electron with the environmental alpha-proton, methylene protons, and one proton of the NH2, and N-14 nucleus were determined. The results were found to be in good agreement with the existing literature data. (C) 2010 Elsevier B.V. All rights reserved.
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    Radiation effect studies in single crystal of Trifluoroacetyl-?-Aminoisobutyric acid
    (Taylor & Francis Ltd, 2015) Baskan, M. Halim; Osmanoglu, Y. Emre; Sutcu, K.; Aydin, M.; Osmanoglu, S.
    In this study, electron paramagnetic resonance of -irradiated single crystals of N-Trifluoroacetyl--amino isobutyric acid (F3Ac-Aib-OH) was investigated at room temperature and analyzed for different orientations of the crystal in the magnetic field. The paramagnetic species in N-Trifluoroacetyl--aminoisobutyric acid was attributed to the CF2-R radical (R= CONHC(CH3)COOH). Hyperfine coupling constants and g value were also determined. In addition, the single crystal of F3Ac-Aib-OH was UV-irradiated and paramagnetic species formed was studied at room temperature. The effects of gamma irradiation on fluoroamino acid and stability were discussed.
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    Structure and behaviour of the free radicals generated in gamma irradiated amino acid and iminodiacetic acid derivatives
    (Pergamon-Elsevier Science Ltd, 2011) Osmanoglu, Semsettin; Aydin, Murat; Osmanoglu, Y. Emre; Dicle, I. Yesim; Baskan, M. Halim
    An EPR study has been carried out to investigate the structure and behaviour of the free radical formed gamma-irradiated L-alaninamide hydrochloride, DL-glutamic acid monohydrate and N-(2-carboxyethyl) iminodiacetic acid powders at room temperature. The observed paramagnetic species have been attributed to the CH3CHCONH2, HOOCCH2CH2CHCOOH and HOOCCH2CH2NCHCH2(COOH)(2) radicals, respectively. Some spectroscopic properties and suggestions concerning possible structure of the radicals were also discussed in this study. Published by Elsevier B.V.