Computer analysis of ESR spectra recorded under gamma-irradiation of polycrystal and glass-like solutions of nucleotides and nitrous bases was carried out to determine the localization sites of free valency (damage) in DNA macromolecule when interacting with water radiolysis products (OH and H). The analysis was performed on a mini-computer with the program of reconstruction of ESR anisotropic spectra in the variation search regime. When calculating the theoretical spectra anisotropic width of the lines, g-factors and HHS constants on X and Z axes were taken into account. Good reproduction of the experimental spectra on the computer was achieved, as a result the ESR spectra were obtained. Relative contribution of each of OH- and H-adducts of nitrous bases to the total ESR spectrum of gamma-irradiated DNA will be determined in future.
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ACS Nano
January 2025
IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, United States.
Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4 electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual lanthanide atoms using a scanning tunneling microscope to probe the atoms bound to a protective insulating film. The atoms on this surface formed a singly charged cation state having an unpaired 6 electron, enabling tunnel current to access their 4 electrons.
View Article and Find Full Text PDFSmall
January 2025
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, China.
How to improve the stability and activity of metal-organic frameworks is an attractive but challenging task in energy conversion and pollutant degradation of metal-organic framework materials. In this paper, a facile method is developed by fabricating titanium dioxide nanoparticles (TiO NPs) layer on 2D copper tetracarboxylphenyl-metalloporphyrin metal-organic frameworks with zinc ions as the linkers (ZnTCuMT-X, "Zn" represented zinc ions as the linkers, the first "T" represented tetracarboxylphenyl-metalloporphyrin (TCPP), "Cu" represented the Cu coordinated into the porphyrin macrocycle, "M" represented metal-organic frameworks, the second "T" represented TiO NPs layer, and "X" represented the added volume of n-tetrabutyl titanate (X = 100, 200, 300 or 400)). It is found that the optimized ZnTCuMT-200 showed greatly and stably enhanced H generation, which is ≈28.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Research Group ESR Spectroscopy, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, Göttingen, Germany.
F electron-nuclear double resonance (ENDOR) spectroscopy is emerging as a method of choice to determine molecular distances in biomolecules in the angstrom to nanometer range. However, line broadening mechanisms in F ENDOR spectra can obscure the detected spin-dipolar coupling that encodes the distance information, thus limiting the resolution and accessible distance range. So far, the origin of these mechanisms has not been understood.
View Article and Find Full Text PDFMolecules
November 2024
Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102A, HR-10000 Zagreb, Croatia.
In this study, we report the syntheses, crystal structures and magnetic properties of ternary copper(II) coordination compounds with l-homoserine (l-Hhser) and 1,10-phenanthroline (phen). Six new coordination compounds were obtained: [Cu(l-hser)(HO)(phen)]SO·5HO (), [Cu(μ-l-hser)(HO)(phen)][Cu(l-hser)(HO)(phen)](SO)∙12HO (), {[Cu(μ-l-hser)(HO)(phen)][Cu(μ-l-hser)(phen)]SO·6HO} (), {[Cu(μ-l-hser)(HO)(phen)]SO·3HO} (), [Cu(l-hser)(HO)(phen)][Cu(l-hser)(CHOH)(phen)]SO·4HO () and {[Cu(l-hser)(CHOH)(phen)][Cu(μ-l-hser)(phen)]SO·5CHOH} () It was shown that slight differences in water content in the synthetic mixtures highly influence the final product, so in some cases, two or three different products were obtained. The compounds were characterized by single-crystal X-ray diffraction and ESR spectroscopy.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
Endohedral metallofullerenes (EMFs) are constructed by fullerene cages encapsulating various metal atoms or metal clusters, which usually exhibit some motion. However, due to the fact that the elusive endohedral dynamics are related to many factors, it remains a challenge to image the motion of internal species. Recently, the electron spin was found to be a sensitive probe to detect the motion of internal species in EMFs.
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