Analytical chemistry

Synthesis of a New Element with Atomic Number Z=117

The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z≥111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.

Synthesis of a New Element with Atomic Number Z=117, Oganessian, Yu. Ts., Abdullin Sh. F., Bailey P. D., Benker D. E., Bennett M. E., Dmitriev S. N., Ezold J. G., Hamilton J. H., Henderson R. A., Itkis M. G., et al. , Phys. Rev. Lett., Apr/2010, Volume 104, Number 14, p.142502, (2010)

Ground State Electron Configuration of Rutherfordium: Role of Dynamic Correlation

The low-lying electronic states of Rf+ and Rf are investigated by the relativistic coupled cluster method based on the Dirac-Coulomb-Breit Hamiltonian. A large basis set (34s24p19d13f8g5h4i) of Gaussian-type orbitals is used. The external 36 electrons are correlated. In contrast with recent multiconfiguration Dirac-Fock (MCDF) results, the 7s26d2 3F2 state is found to be the ground state of the atom, lying about 0.30 eV below the 7s27p6d 3D2 state (the MCDF ground state). The dynamic correlation of the system, requiring virtual orbitals with l up to 6, is responsible for the reversal. The first ionization potential of the atom is predicted at 6.01 eV.

Ground State Electron Configuration of Rutherfordium: Role of Dynamic Correlation, Eliav, Ephraim, Kaldor Uzi, and Ishikawa Yasuyuki , Physical Review Letters, 2/1995, Volume 74, Issue 7, p.1079 - 1082, (1995)

X-ray study of the alkali metals at low temperatures

Cold working of sodium metal converts body centred sodium metal to a mixture of a hexagonal form and body centred sodium at 5 K. The hexagonal from converts back to the body-centred form at 100-100 K.

Cold working of lithium metal converts body centred lithium metal to a mixture of a hexagonal form and body centred lithium at 78 K.

Potassium, rubidium, and caesium retain their body centred structure after cooling

X-ray study of the alkali metals at low temperatures, Barrett, C. S. , Acta Crystallographica, 08/1956, Volume 9, Issue 8, p.671 - 677, (1956)

Crystallographic Data 186. Lithium

Lithium at room temperature is body-centered cubic with 2 atoms per unit cell. The lattice constant for lithium metal is 3.51004 ± 0.00041 Å at 25" C. The theoretical density is 533 kg m–3 and the Li—Li bond distance for coordination number 8 is 3.0398 Å.

SMILES: [Li]
InChI: InChI=1/Li

Crystallographic Data 186. Lithium, Nadler, M. R. /, and Kempier C. P. , Analytical Chemistry, 12/1959, Volume 31, Issue 12, p.2109 - 2109, (1959)

Crystallographic Data. 177. Uranium Mononitride

Crystal structure of uranium nitride, UN. The structure is face-centered cubic with a lattice constant of 4889 ± 0.001 Å at 26°C and sodium chloride type. The theoretical density is 14315 kg m–3, and the U—N bond distance for coordination number 6 is 2.4449 Å.

Crystallographic Data. 177. Uranium Mononitride, Kempter, Charles, McGuire Joseph, and Nadler M. , Analytical Chemistry, 01/1959, Volume 31, Issue 1, p.156 - 157, (1959)

Energy dependence of 209-Bi fragmentation in relativistic nuclear collisions

The results of cross-section measurements for the reactions 209Bi(12C,X)Au, E=4.8 and 25.2 GeV and 209Bi(20Ne,X)Au, E=8.0 GeV are reported. The observed yields of the gold isotopes show a similar dependence on mass number for each reaction, differing slightly in the position of the centroid of the distribution. As the projectile energy increases, the inferred excitation energy of the primary residues remains the same or decreases slightly. This observation is in agreement with the predictions of the intranuclear cascade model of relativistic heavy ion collisions.

NUCLEAR REACTIONS 209Bi(12C,X)Au, E=4.8,25.2 GeV; 209Bi(20Ne,X)Au, E=8.0 GeV; measured Au isotopic distributions, relativistic heavy ions, target fragmentation, Ge(Li) spectroscopy.

Energy dependence of 209-Bi fragmentation in relativistic nuclear collisions, Aleklett, K., Morrissey D., Loveland W., McGaughey P., and Seaborg G. , Physical Review C, 3/1981, Volume 23, Issue 3, p.1044 - 1046, (1981)

Die Kristallstrukturen von ScCl3, TiCl3 und VCl3

ScCl3, TiCl3 und VCl3 kristallisieren hexagonal-rhomboedrisch in dem gleichen Gitter wie FeCl3 (DO5-Typ).

Die Kristallstrukturen von ScCl3, TiCl3 und VCl3, Klemm, Wilhelm, and Krose Ehrhard , Zeitschrift für anorganische Chemie, 05/1947, Volume 253, Issue 3-4, p.218 - 225, (1947)

Depletion of the Ozone Layer in the 21st Century

Depletion of the Ozone Layer in the 21st Century, Dameris, Martin , Angewandte Chemie International Edition, Volume 9999, Number 9999, p.NA, (2009)

Soluble Mn (III) in suboxic zones

Abstract: soluble manganese(III) [Mn(III)] has been thought to disproportionate to soluble Mn(II) and particulate MnIVO2 in natural waters, although it persists as complexes in laboratory solutions. We report that, in the Black Sea, soluble Mn(III) concentrations were as high as 5 micromolar and constituted up to 100% of the total dissolved Mn pool. Depth profiles indicated that soluble Mn(III) was produced at the top of the suboxic zone by Mn(II) oxidation and at the bottom of the suboxic zone by MnIVO2 reduction, then stabilized in each case by unknown natural ligands. We also found micromolar concentrations of dissolved Mn(III) in the Chesapeake Bay. Dissolved Mn(III) can maintain the existence of suboxic zones because it can act as either an electron acceptor or donor. Our data indicate that Mn(III) should be ubiquitous at all water column and sediment oxic/anoxic interfaces in the environment.

Soluble Mn (III) in suboxic zones, Trouwborst, R., Clement B., Tebo B., and Glazer B. , science, Jan, (2006)

WebElements: the periodic table on the WWW [http://www.webelements.com/]

Copyright 1993-2011 Mark Winter [The University of Sheffield and WebElements Ltd, UK]. All rights reserved.