A simple way to obtain stable mono-decker porphyrin complexes with heavy metal atoms

2021 ◽  
pp. 1-4
Author(s):  
Dmitry Andreevich Erzunov ◽  
Anna Aleksandrovna Bontar ◽  
Natalya Anatolievna Futerman ◽  
Arthur Sergeevich Vashurin ◽  
Svetlana Gennadievna Pukhovskaya
Keyword(s):  
Heavy Metal ◽  
Metal Atoms ◽  
Stable Mono

A synchrotron X-ray study of the electron density in C-type rare earth oxides

1996 ◽  
Vol 52 (3) ◽  
pp. 414-422 ◽  
Author(s):  
E. N. Maslen ◽  
V. A. Streltsov ◽  
N. Ishizawa
Keyword(s):  
Heavy Metal ◽  
Rare Earth ◽  
Electron Density ◽  
Approximate Symmetry ◽  
Data Set ◽  
X Ray ◽  
Metal Atoms ◽  
Structure Factors ◽  
Deformation Electron Density ◽  
Synthetic Crystals

Structure factors for small synthetic crystals of the C-type rare earth (RE) sesquioxides Y2O3, Dy2O3 and Ho2O3 were measured with focused λ = 0.7000 (2) Å, synchrotron X-radiation, and for Ho2O3 were re-measured with an MoKα (λ = 0.71073 Å) source. Approximate symmetry in the deformation electron density (Δρ) around a RE atom with pseudo-octahedral O coordination matches the cation geometry. Interactions between heavy metal atoms have a pronounced effect on the Δρ map. The electron-density symmetry around a second RE atom is also perturbed significantly by cation–anion interactions. The compounds magnetic properties reflect this complexity. Space group Ia{\bar 3}, cubic, Z = 16, T = 293 K: Y2O3, Mr = 225.82, a = 10.5981 (7) Å, V = 1190.4 (2) Å3, Dx = 5.040 Mg m−3, μ 0.7 = 37.01 mm−1, F(000) = 1632, R = 0.067, wR = 0.067, S = 9.0 (2) for 1098 unique reflections; Dy2O3, Mr = 373.00, a = 10.6706 (7) Å, V = 1215.0 (2) Å3, Dx = 8.156 Mg m−3, μ 0.7 = 44.84 mm−1, F(000) = 2496, R = 0.056, wR = 0.051, S = 7.5 (2) for 1113 unique reflections; Ho2O3, Mr = 377.86, a = 10.606 (2) Å, V = 1193.0 (7) Å3, Dx = 8.415 Mg m−3, μ 0.7 = 48.51 mm−1 F(000) = 2528, R = 0.072, wR = 0.045, S = 9.2 (2) for 1098 unique reflections of the synchrotron data set.

scholarly journals Ruderman–Kittel–Kasuya–Yosida-type interfacial Dzyaloshinskii–Moriya interaction in heavy metal/ferromagnet heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Taehyun Kim ◽  
In Ho Cha ◽  
Yong Jin Kim ◽  
Gyu Won Kim ◽  
Andrey Stashkevich ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Exchange Coupling ◽  
Spin Orbit Coupling ◽  
Conduction Electrons ◽  
Indirect Exchange ◽  
Metal Atoms ◽  
Technological Potential ◽  
Interfacial Modification ◽  
Coupling Phenomena ◽  
Moriya Interaction

AbstractThe manipulation of magnetization with interfacial modification using various spin-orbit coupling phenomena has been recently revisited due to its scientific and technological potential for next-generation memory devices. Herein, we experimentally and theoretically demonstrate the interfacial Dzyaloshinskii–Moriya interaction characteristics penetrating through a MgO dielectric layer inserted between the Pt and CoFeSiB. The inserted MgO layer seems to function as a chiral exchange interaction mediator of the interfacial Dzyaloshinskii–Moriya interaction from the heavy metal atoms to ferromagnet ones. The potential physical mechanism of the anti-symmetric exchange is based on the tunneling-like behavior of conduction electrons through the semi-conductor-like ultrathin MgO. Such behavior can be correlated with the oscillations of the indirect exchange coupling of the Ruderman–Kittel–Kasuya–Yosida type. From the theoretical demonstration, we could provide approximate estimation and show qualitative trends peculiar to the system under investigation.

scholarly journals Correction: Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms

2021 ◽  
Author(s):  
Magdalena Woińska ◽  
Michał L. Chodkiewicz ◽  
Krzysztof Woźniak
Keyword(s):  
Heavy Metal ◽  
Hydrogen Atoms ◽  
Metal Atoms

Correction for ‘Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms’ by Magdalena Woińska et al., Chem. Commun., 2021, 57, 3652–3655, DOI: 10.1039/D0CC07661A.

Protein Visualization with Crystal Contrast

1976 ◽  
Vol 34 ◽  
pp. 486-487
Author(s):  
R. L. Hines
Keyword(s):  
Heavy Metal ◽  
Single Crystal ◽  
Biological Molecules ◽  
Single Crystal Film ◽  
Metal Atoms ◽  
Crystal Film ◽  
Contrast Mechanism ◽  
Good Contrast

Good contrast can be obtained for unstained protein in biological molecules when the molecules are supported on top of a single crystal film oriented so as to strongly diffract the illumination electrons. If the objective aperture excludes the diffracted beam, the strongly diffracting regions in the crystal film will show up in the image as dark bands a micron or more wide known as bend contours. The bend contour width is determined by the wrinkling of the crystal film which causes local changes in the crystal support film orientation. Biological molecules viewed near bend contours show contrast at exact focus without requiring staining or shadowing with heavy metal atoms. The bend contours are easily moved around by tilting the sample with a tilt stage so that it is not difficult to orient the crystal support so that it is strongly diffracting where ever the biological molecules are located on the support film. The details of the contrast mechanism have been discussed by Hines and Howie.

Selective Staining of Nucleic Acids with Indium

1968 ◽  
Vol 26 ◽  
pp. 42-43
Author(s):  
W. G. Aldridge ◽  
J. R. Coleman
Keyword(s):  
Heavy Metal ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Chemical Reactivity ◽  
Chemical Properties ◽  
Strong Electron ◽  
Metal Compounds ◽  
Selective Staining ◽  
Metal Atoms ◽  
Reaction Spectrum

Heavy metal compounds are used to increase contrast in electron microscope specimens by virtue of strong electron scattering properties. Chemical properties of heavy metal atoms cause them to discriminate amongst available ligands, a property useful for biological specimens. Decreasing available specimen ligand types produces a narrow reaction spectrum. Taking advantage of both these controlling factors, one can produce a very narrow reaction spectrum and thus high selectivity. This approach was utilized in the development of methods for the use of indium as an “electron stain” for nucleic acids. Here selectivity is greatly enhanced by reduction and acylation reactions which precede exposure to indium trichloride dissolved in anhydrous acetone. Nucleic acid phosphate is the predominant binding site but some non-nucleic acid ligands still bind indium. To further increase selectivity and provide greater contrast (thus lower detection limits), more efficient blocking reactions of broader chemical reactivity plus techniques to increase the amount of heavy metal bound to nucleic acid were sought.

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