Journal ArticleDOI
E.S.R. and ENDOR studies of X-irradiated 4-phenyl-3-thiosemicarbazide single crystals
W.H. Nelson,C.D. Gill +1 more
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In this article, a radical identified as C6H5NHCS[Ndot]NH2 has been studied with E.S.R. and endor spectroscopy in X-irradiated 4-phenyl-3-thiosemicarbazide single crystals.Abstract:
A radical identified as C6H5NHCS[Ndot]NH2 has been studied with E.S.R. and ENDOR spectroscopy in X-irradiated 4-phenyl-3-thiosemicarbazide single crystals. The ENDOR measurements reveal interactions between the unpaired electron and two hydrogen nuclei with the principal values These interactions are of NH α-type and arise from the amino hydrogens. The E.S.R. indicates additional interaction between the unpaired electron and three nitrogen nuclei. These interactions are all axially symmetric about the direction of intermediate hydrogen coupling and have principal values estimated to be From these results and those from the hydrogen interactions, the nitrogen interaction labelled N2 is assigned to the amino nitrogen.read more
Citations
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Alanine Radicals. 2. The Composite Polycrystalline Alanine EPR Spectrum Studied by ENDOR, Thermal Annealing, and Spectrum Simulations†
TL;DR: In this paper, the authors used powder and single-crystal X-, K-, and Q-band electron paramagnetic resonance (EPR) spectroscopy, X-band powder electron−nuclear double resonance (ENDOR), thermal annealing, and EPR spectrum simulations.
Journal ArticleDOI
Free radical formation in single crystals of 2'-deoxyguanosine 5'-monophosphate tetrahydrate disodium salt: an EPR/ENDOR study.
TL;DR: How radicals barely traceable in the EPR spectra may be identified due to strong ENDOR resonances is illustrated, and the observation of a stable radical with parameters similar to those expected for the charge guanine cation is interesting with regard to the nature of the primary radicals stabilized in X-irradiated DNA.
Journal ArticleDOI
ESR study of the guanine cation
TL;DR: In this article, a guanine cation was observed in a single crystal of HCl:H2O. Spectral parameters for the cation include N3 and N10 hyperfine couplings, a C8-Hα hyperfine coupling, and two small exchangeable couplings presumably from the N10 protons.
Journal ArticleDOI
ESR and ENDOR study of the guanine cation: Secondary product in 5’‐dGMP
TL;DR: In this paper, the results of detailed ESR and ENDOR experiments at 10 K conflicting with the above results were reported, showing that one of the radicals exhibited two α-proton type couplings.
Journal ArticleDOI
ESR/ENDOR study of guanine.HCl.2H2O X-irradiated at 20K.
TL;DR: The evidence indicated that Radical 4 was the result of net hydrogen abstraction from N9 of the guanine base, and reaction mechanisms are proposed to account for formation of the products.
References
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Journal ArticleDOI
The electron spin resonance spectrum of NH(SO3 -) in γ-irradiated potassium sulphamate
TL;DR: The electron spin resonance spectrum of the radical NH(SO3) trapped in a single crystal of potassium sulphamate is interpreted in this paper, where hyperfine couplings for the hydrogen and nitrogen nuclei are given.
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Electron spin resonance of x-irradiated single crystals of hydroxyurea.
TL;DR: In this article, the free radical responsible for the electron spin resonance has been identified as NH2CONH, and the measurements indicate that 41% of the unpaired electron is localized in the 2p orbital of the nitrogen atom.
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Unstable intermediates. Part C. Urea and formamide: the radicals ĊONH2 and H2NCONH
TL;DR: In this article, it was shown that urea and formamide, on exposure to 60Co γ-rays, gave e.r.s. spectra characteristic of CONH2 radicals.
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ENDOR spectra of 14N and H in free radicals formed by γ‐irradiation of dimethylglyoxime single crystals
TL;DR: In this paper, the endor spectra of the coupling nuclei in two species of radicals formed in γ-irradiated dimethylglyoxime have been measured and the more abundant of these has the form RC(CH3)NO with the unpaired electron concentrated on the NO group.
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Electron Spin Resonance Study of γ‐Irradiated Single Crystals of Semicarbazide Hydrochloride
TL;DR: In this paper, electron spin resonance studies of γ-irradiated single crystals of semicarbazide hydrochloride and the deuterated form, ND2CONHND3+·Cl−, revealed the presence of the stably trapped ·N(α)H(α)-3+ radical obtained by C-N bond rupture of the parent molecule.