EPR study of radiation damage in gamma-irradiated 3-nitroacetophenone single crystal

Çalişkan, Betül; Çalişkan, Ali Cengiz

doi:10.1080/10420150.2017.1320800

Cited by 11 publications

(7 citation statements)

References 54 publications

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“…The radical mechanism of the trans-chalcone is the same as the radical mechanisms of 3-nitroacetophenone [70], hydroquinone [71], potassium hydroquinone monosulfonate [72], semiquinone, tetrachlorosemiquinone [71,73], tetrafluoro p-semiquinone [74], succinic anhydride [75], dihydroxyfumaric acid, ascorbic acid, and reductic acid [71,73]. Molecular oxygen is the electron acceptor, as demonstrated by spin trapping [76].…”

Section: Discussionmentioning

confidence: 99%

Electron Paramagnetic Resonance Study of the Radiation Damage in Trans-Chalcone Single Crystal

Çalişkan

2019

Acta Phys. Pol. A

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Gamma irradiated trans-chalcone (C15H12O) single crystals are investigated at 120 K using electron paramagnetic resonance technique. Trans-chalcone single crystals are irradiated with 60 Co-γ rays, at room temperature. The EPR spectra of gamma irradiated trans-chalcone single crystals are studied for different orientations of crystals in a magnetic field. The spectra are found to be temperature independent. The structure of the radical produced by γ-irradiation of a single crystal of trans-chalcone is discussed. The investigation of EPR spectra of gamma-irradiated single crystals of trans-chalcone shows the presence of two trans-chalcone anion radicals. The two trans-chalcone anion radicals are created by the scission of the carbon-oxygen double bond. The reduction of trans-chalcone is identified which is formed by the addition of an electron to oxygen of the formed CO bond. The principal values of the hyperfine coupling tensors of the unpaired electron and the principal values of the g-tensors and direction cosines of the radiation damage centers are determined. The results are found to be in good agreement with the existing literature.

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Section: Discussionmentioning

confidence: 99%

Electron Paramagnetic Resonance Study of the Radiation Damage in Trans-Chalcone Single Crystal

Çalişkan

2019

Acta Phys. Pol. A

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“…The hyperfine structure interaction is an important interaction for EPR spectroscopy. In EPR spectroscopy, the effect of the hyperfine structure interaction is taken into account together with the electron Zeeman interaction [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In addition, nuclear Zeeman interaction, the zero-field interaction, and the nuclear quadrupole interaction have an effect on EPR spectroscopy.…”

Section: Resultsmentioning

confidence: 99%

Dipolar Interactions: Hyperfine Structure Interaction and Fine Structure Interactions

Çalişkan¹,

Çalişkan²

2020

Quantum Mechanics

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The interaction between the nuclear spin and the electron spin creates a hyperfine structure. Hyperfine structure interaction occurs in paramagnetic structures with unpaired electrons. Therefore, hyperfine structure interaction is the most important of the fundamental parameters investigated by electron paramagnetic resonance (EPR) spectroscopy. For EPR spectroscopy the two effective Hamiltonian terms are the hyperfine structure interaction and the electronic Zeeman interaction. The hyperfine structure interaction has two types as isotropic and anisotropic hyperfine structure interactions. The zero-field splitting term (electronic quadrupole fine structure), the nuclear Zeeman term, and the nuclear quadrupole interaction term are among the Hamiltonian terms used in EPR. However, their effects are not as much as the term of the hyperfine structure interaction. The zero-field splitting term and the nuclear quadrupole interaction term are the fine structure terms. The interaction of two electron spins create a zero-field splitting, the interaction between the two nucleus spins form the nuclear quadrupole interaction. Hyperfine structure interaction, zero-field interaction, and nuclear quadrupole interaction are subclasses of dipolar interaction. Interaction tensors are available for all three interactions. Keywords: dipolar interaction hyperfine structure, isotropic hyperfine structure, anisotropic hyperfine structure, the zero-field splitting, the nuclear quadrupole interaction, the electronic Zeeman interaction, the nuclear Zeeman term, EPR

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“…Free Radicals, Antioxidants and Diseases temperature range of 120-360 K, we decided that the radiation damage center in the sample was due to the break of the pi bond in the carbon-oxygen double bond. It was seen that the unpaired electron interacted with all the protons in the molecular structure [8].…”

Section: Gamma-irradiated 3-nitroacetophenone Single Crystalmentioning

confidence: 99%

“…Potassium hydroquinone monosulfonate (PHM), succinic anhydride and 3-nitroacetophenone compounds are antioxidants. Paramagnetic centers formed by gamma irradiation effect on single crystals of these materials were analyzed by the EPR method [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

EPR Analysis of Antioxidant Compounds

Çalişkan¹,

Çalişkan²

2018

Free Radicals, Antioxidants and Diseases

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A free radical is a molecular species having an unpaired electron and it is a highly reactive entity and unstable. A free radical is a molecule with one or more unpaired electrons in its outer shell. Free radicals can be formed by chemical bond breakage from molecules or by redox reactions. When cells use oxygen, the oxidative stress occurs. The oxidative stress causes free radical formation. Free radicals can also be generated from ionizing radiations, ozone, heavy metal poisoning, cigarette smoking, and chronic alcohol intake. These free radicals are highly reactive and oxidize biomolecules leading to tissue injury and cell death. They also cause toxic effects and diseases. Antioxidants neutralize free radicals resulting from oxidative stress. Antioxidants play an important role in the treatment of diseases. The most suitable method for the analysis of free radicals is the electron paramagnetic resonance (EPR) spectroscopy method. The EPR method detects a paramagnetic center with a single electron. It gives information about the interactions with other nuclei around one electron. It provides information on the structure and environment of radicals.

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EPR study of radiation damage in gamma-irradiated 3-nitroacetophenone single crystal

Cited by 11 publications

References 54 publications

Electron Paramagnetic Resonance Study of the Radiation Damage in Trans-Chalcone Single Crystal

Electron Paramagnetic Resonance Study of the Radiation Damage in Trans-Chalcone Single Crystal

Dipolar Interactions: Hyperfine Structure Interaction and Fine Structure Interactions

EPR Analysis of Antioxidant Compounds

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