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Daniel Fink - One of the best experts on this subject based on the ideXlab platform.
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determination of the first ionization energy of polonium by resonance ionization spectroscopy part ii measurement of odd parity rydberg states at cern isolde
Spectrochimica Acta Part B: Atomic Spectroscopy, 2019Co-Authors: Daniel Fink, K Blaum, V N Fedosseev, B A Marsh, R E Rossel, S RotheAbstract:Abstract Polonium (Po) is one of the rarest elements in Earth's crust. None of its isotopes are stable and sufficient amounts for systematic experimental studies of its most fundamental properties are only available by artificial production. At the radioactive ion beam facility ISOLDE at CERN, 208Po was produced by proton-induced spallation of uranium. Using the technique of in-source Resonance Ionization Spectroscopy the ionization threshold was probed with a tunable dye laser. A spectrum of 110 previously undocumented odd-parity Rydberg states was observed. Applying the Rydberg formalism to the data enabled the determination of the first ionization energy of polonium as 67896.310(14)(30) cm−1 or 8.4180700(18)(37) eV. This is a precision improvement of more than 600 over the existing literature value. A comparison with the homologous elements sulfur, selenium and tellurium enabled the assignment of the Electron Configuration of the resonances found in the spectrum.
Brian L. Scott - One of the best experts on this subject based on the ideXlab platform.
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identification of the formal 2 oxidation state of plutonium synthesis and characterization of puii c5h3 sime3 2 3
Journal of the American Chemical Society, 2017Co-Authors: Cory J. Windorff, Filipp Furche, Guo P. Chen, Justin N. Cross, William J. Evans, Andrew J. Gaunt, Michael T. Janicke, Stosh A. Kozimor, Brian L. ScottAbstract:Over 70 years of chemical investigations have shown that plutonium exhibits some of the most complicated chemistry in the periodic table. Six Pu oxidation states have been unambiguously confirmed (0 and +3 to +7), and four different oxidation states can exist simultaneously in solution. We report a new formal oxidation state for plutonium, namely Pu2+ in [K(2.2.2-cryptand)][PuIICp″3], Cp″ = C5H3(SiMe3)2. The synthetic precursor PuIIICp″3 is also reported, comprising the first structural characterization of a Pu–C bond. Absorption spectroscopy and DFT calculations indicate that the Pu2+ ion has predominantly a 5f6 Electron Configuration with some 6d mixing.
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Identification of the Formal +2 Oxidation State of Plutonium: Synthesis and Characterization of {PuII[C5H3(SiMe3)2]3}−
2017Co-Authors: Cory J. Windorff, Filipp Furche, Guo P. Chen, Justin N. Cross, William J. Evans, Andrew J. Gaunt, Michael T. Janicke, Stosh A. Kozimor, Brian L. ScottAbstract:Over 70 years of chemical investigations have shown that plutonium exhibits some of the most complicated chemistry in the periodic table. Six Pu oxidation states have been unambiguously confirmed (0 and +3 to +7), and four different oxidation states can exist simultaneously in solution. We report a new formal oxidation state for plutonium, namely Pu2+ in [K(2.2.2-cryptand)][PuIICp″3], Cp″ = C5H3(SiMe3)2. The synthetic precursor PuIIICp″3 is also reported, comprising the first structural characterization of a Pu–C bond. Absorption spectroscopy and DFT calculations indicate that the Pu2+ ion has predominantly a 5f6 Electron Configuration with some 6d mixing
Sebastian Riedel - One of the best experts on this subject based on the ideXlab platform.
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identification of an iridium containing compound with a formal oxidation state of ix
Nature, 2014Co-Authors: Guanjun Wang, James T Goettel, Mingfei Zhou, Tobias Schloder, Gary J Schrobilgen, Sebastian RiedelAbstract:The tetrahedral iridium tetroxide cation [IrO4]+, which has an iridium 5d0 valence Electron Configuration and a formal oxidation state of IX, is generated in the gas phase, identified by infrared photodissociation spectroscopy, and predicted, by quantum chemical calculations, to be the most stable of all possible [IrO4]+ isomers. The concept of formal oxidation states is fundamental to our understanding of general chemistry and is enshrined in the periodic table that groups elements principally by atomic number and Electron Configuration. The preparation and characterization of compounds containing elements with unusual oxidation states is of therefore of great interest to inorganic chemists. The highest experimentally known formal oxidation state of any chemical element is currently VIII. Here, the authors report the formation and infrared photodissociation spectroscopic identification of the iridium tetroxide cation, [IrO4]+, in which the iridium centre has a formal oxidation state of IX, the highest oxidation state known so far. One of the most important classifications in chemistry and within the periodic table is the concept of formal oxidation states1,2,3,4. The preparation and characterization of compounds containing elements with unusual oxidation states is of great interest to chemists5. The highest experimentally known formal oxidation state of any chemical element is at present VIII2,3,4, although higher oxidation states have been postulated6,7. Compounds with oxidation state VIII include several xenon compounds8 (for example XeO4 and XeO3F2) and the well-characterized species RuO4 and OsO4 (refs 2, 3, 4). Iridium, which has nine valence Electrons, is predicted to have the greatest chance of being oxidized beyond the VIII oxidation state1. In recent matrix-isolation experiments, the IrO4 molecule was characterized as an isolated molecule in rare-gas matrices9. The valence Electron Configuration of iridium in IrO4 is 5d1, with a formal oxidation state of VIII. Removal of the remaining d Electron from IrO4 would lead to the iridium tetroxide cation ([IrO4]+), which was recently predicted to be stable10 and in which iridium is in a formal oxidation state of IX. There has been some speculation about the formation of [IrO4]+ species11,12, but these experimental observations have not been structurally confirmed. Here we report the formation of [IrO4]+ and its identification by infrared photodissociation spectroscopy. Quantum-chemical calculations were carried out at the highest level of theory that is available today, and predict that the iridium tetroxide cation, with a Td-symmetrical structure and a d0 Electron Configuration, is the most stable of all possible [IrO4]+ isomers.
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identification of an iridium containing compound with a formal oxidation state of ix
Nature, 2014Co-Authors: Guanjun Wang, James T Goettel, Mingfei Zhou, Tobias Schloder, Gary J Schrobilgen, Jing Su, Jun Li, Sebastian RiedelAbstract:The tetrahedral iridium tetroxide cation [IrO4]+, which has an iridium 5d0 valence Electron Configuration and a formal oxidation state of IX, is generated in the gas phase, identified by infrared photodissociation spectroscopy, and predicted, by quantum chemical calculations, to be the most stable of all possible [IrO4]+ isomers.
Filipp Furche - One of the best experts on this subject based on the ideXlab platform.
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synthesisand magnetism of neutral linear metallocenecomplexes of terbium ii and dysprosium ii
Journal of the American Chemical Society, 2019Co-Authors: Colin A Gould, Randall K Mcclain, Jason M Yu, Thomas J Groshens, Filipp Furche, Benjamin G Harvey, Jeffrey R LongAbstract:The divalent metallocene complexes Ln(CpiPr5)2 (Ln = Tb, Dy) were synthesized through the KC8 reduction of Ln(CpiPr5)2I intermediates and represent the first examples of neutral, linear metallocenes for these elements. X-ray diffraction analysis, density functional theory calculations, and magnetic susceptibility measurements indicate a 4fn5d1 Electron Configuration with strong s/d mixing that supports the linear coordination geometry. A comparison of the magnetic relaxation behavior of the two divalent metallocenes relative to salts of their trivalent counterparts, [Ln(CpiPr5)2][B(C6F5)4], reveals that lanthanide reduction has opposing effects for dysprosium and terbium, with magnetic relaxation times increasing from TbIII to TbII and decreasing from DyIII to DyII. The impact of this effect is most notably evident for Tb(CpiPr5)2, which displays an effective thermal barrier to magnetic relaxation of 1205 cm–1 and a 100-s blocking temperature of 52 K, the highest values yet observed for any nondysprosium ...
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synthesis and magnetism of neutral linear metallocene complexes of terbium ii and dysprosium ii
Journal of the American Chemical Society, 2019Co-Authors: Colin A Gould, Randall K Mcclain, Thomas J Groshens, Filipp Furche, Benjamin G Harvey, Jeffrey R LongAbstract:The divalent metallocene complexes Ln(CpiPr5)2 (Ln = Tb, Dy) were synthesized through the KC8 reduction of Ln(CpiPr5)2I intermediates and represent the first examples of neutral, linear metallocenes for these elements. X-ray diffraction analysis, density functional theory calculations, and magnetic susceptibility measurements indicate a 4fn5d1 Electron Configuration with strong s/d mixing that supports the linear coordination geometry. A comparison of the magnetic relaxation behavior of the two divalent metallocenes relative to salts of their trivalent counterparts, [Ln(CpiPr5)2][B(C6F5)4], reveals that lanthanide reduction has opposing effects for dysprosium and terbium, with magnetic relaxation times increasing from TbIII to TbII and decreasing from DyIII to DyII. The impact of this effect is most notably evident for Tb(CpiPr5)2, which displays an effective thermal barrier to magnetic relaxation of 1205 cm–1 and a 100-s blocking temperature of 52 K, the highest values yet observed for any nondysprosium ...
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identification of the formal 2 oxidation state of plutonium synthesis and characterization of puii c5h3 sime3 2 3
Journal of the American Chemical Society, 2017Co-Authors: Cory J. Windorff, Filipp Furche, Guo P. Chen, Justin N. Cross, William J. Evans, Andrew J. Gaunt, Michael T. Janicke, Stosh A. Kozimor, Brian L. ScottAbstract:Over 70 years of chemical investigations have shown that plutonium exhibits some of the most complicated chemistry in the periodic table. Six Pu oxidation states have been unambiguously confirmed (0 and +3 to +7), and four different oxidation states can exist simultaneously in solution. We report a new formal oxidation state for plutonium, namely Pu2+ in [K(2.2.2-cryptand)][PuIICp″3], Cp″ = C5H3(SiMe3)2. The synthetic precursor PuIIICp″3 is also reported, comprising the first structural characterization of a Pu–C bond. Absorption spectroscopy and DFT calculations indicate that the Pu2+ ion has predominantly a 5f6 Electron Configuration with some 6d mixing.
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Identification of the Formal +2 Oxidation State of Plutonium: Synthesis and Characterization of {PuII[C5H3(SiMe3)2]3}−
2017Co-Authors: Cory J. Windorff, Filipp Furche, Guo P. Chen, Justin N. Cross, William J. Evans, Andrew J. Gaunt, Michael T. Janicke, Stosh A. Kozimor, Brian L. ScottAbstract:Over 70 years of chemical investigations have shown that plutonium exhibits some of the most complicated chemistry in the periodic table. Six Pu oxidation states have been unambiguously confirmed (0 and +3 to +7), and four different oxidation states can exist simultaneously in solution. We report a new formal oxidation state for plutonium, namely Pu2+ in [K(2.2.2-cryptand)][PuIICp″3], Cp″ = C5H3(SiMe3)2. The synthetic precursor PuIIICp″3 is also reported, comprising the first structural characterization of a Pu–C bond. Absorption spectroscopy and DFT calculations indicate that the Pu2+ ion has predominantly a 5f6 Electron Configuration with some 6d mixing
S Rothe - One of the best experts on this subject based on the ideXlab platform.
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determination of the first ionization energy of polonium by resonance ionization spectroscopy part ii measurement of odd parity rydberg states at cern isolde
Spectrochimica Acta Part B: Atomic Spectroscopy, 2019Co-Authors: Daniel Fink, K Blaum, V N Fedosseev, B A Marsh, R E Rossel, S RotheAbstract:Abstract Polonium (Po) is one of the rarest elements in Earth's crust. None of its isotopes are stable and sufficient amounts for systematic experimental studies of its most fundamental properties are only available by artificial production. At the radioactive ion beam facility ISOLDE at CERN, 208Po was produced by proton-induced spallation of uranium. Using the technique of in-source Resonance Ionization Spectroscopy the ionization threshold was probed with a tunable dye laser. A spectrum of 110 previously undocumented odd-parity Rydberg states was observed. Applying the Rydberg formalism to the data enabled the determination of the first ionization energy of polonium as 67896.310(14)(30) cm−1 or 8.4180700(18)(37) eV. This is a precision improvement of more than 600 over the existing literature value. A comparison with the homologous elements sulfur, selenium and tellurium enabled the assignment of the Electron Configuration of the resonances found in the spectrum.