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Bernd Von Issendorff - One of the best experts on this subject based on the ideXlab platform.
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electronic ground states of fe2 and co2 as determined by x ray absorption and x ray magnetic Circular Dichroism Spectroscopy
Journal of Chemical Physics, 2015Co-Authors: V Zamudiobayer, K Hirsch, A Langenberg, A ławicki, Akira Terasaki, Bernd Von IssendorffAbstract:The (6)Π electronic ground state of the Co2 (+) diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, (6)Φ, (8)Φ, and (8)Γ, for the electronic ground state of Fe2 (+) have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of 3d transition elements cannot generally be assumed to be connected by a one-electron process.
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Electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Pi$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^8\Phi$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ transition elements cannot generally be assumed to be connected by a one-electron process.
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High orbital angular momentum quantum numbers in the electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
arXiv: Chemical Physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^6\Gamma$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.
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Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic Circular Dichroism Spectroscopy in an ion trap.
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Ławicki, M. Kossick, J. T. LauAbstract:The electronic structure and magnetic moments of free Mn2+ and Mn3+ are characterized by 2p x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results directly show that localized magnetic moments of 5 μB are created by 3d5(6S) states at each ionic core, which are coupled ferromagnetically to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly occupied 4s derived antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μB for Mn2+ and 16 μB for Mn3+, with no contribution of orbital angular momentum.
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Maximum spin polarization in chromium dimer cations as demonstrated by X-ray magnetic Circular Dichroism Spectroscopy.
Angewandte Chemie (International ed. in English), 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Andreas Langenberg, Markus Niemeyer, M. Vogel, A. Ławicki, J. Tobias Lau, Bernd Von IssendorffAbstract:X-ray magnetic Circular Dichroism Spectroscopy has been used to characterize the electronic structure and magnetic moment of Cr2+. Our results indicate that the removal of a single electron from the 4sσg bonding orbital of Cr2 drastically changes the preferred coupling of the 3d electronic spins. While the neutral molecule has a zero-spin ground state with a very short bond length, the molecular cation exhibits a ferromagnetically coupled ground state with the highest possible spin of S=11/2, and almost twice the bond length of the neutral molecule. This spin configuration can be interpreted as a result of indirect exchange coupling between the 3d electrons of the two atoms that is mediated by the single 4s electron through a strong intraatomic 3d-4s exchange interaction. Our finding allows an estimate of the relative energies of two states that are often discussed as ground-state candidates, the ferromagnetically coupled 12Σ and the low-spin 2Σ state.
V. Zamudio-bayer - One of the best experts on this subject based on the ideXlab platform.
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Electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Pi$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^8\Phi$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ transition elements cannot generally be assumed to be connected by a one-electron process.
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High orbital angular momentum quantum numbers in the electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
arXiv: Chemical Physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^6\Gamma$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.
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Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic Circular Dichroism Spectroscopy in an ion trap.
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Ławicki, M. Kossick, J. T. LauAbstract:The electronic structure and magnetic moments of free Mn2+ and Mn3+ are characterized by 2p x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results directly show that localized magnetic moments of 5 μB are created by 3d5(6S) states at each ionic core, which are coupled ferromagnetically to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly occupied 4s derived antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μB for Mn2+ and 16 μB for Mn3+, with no contribution of orbital angular momentum.
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Maximum spin polarization in chromium dimer cations as demonstrated by X-ray magnetic Circular Dichroism Spectroscopy.
Angewandte Chemie (International ed. in English), 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Andreas Langenberg, Markus Niemeyer, M. Vogel, A. Ławicki, J. Tobias Lau, Bernd Von IssendorffAbstract:X-ray magnetic Circular Dichroism Spectroscopy has been used to characterize the electronic structure and magnetic moment of Cr2+. Our results indicate that the removal of a single electron from the 4sσg bonding orbital of Cr2 drastically changes the preferred coupling of the 3d electronic spins. While the neutral molecule has a zero-spin ground state with a very short bond length, the molecular cation exhibits a ferromagnetically coupled ground state with the highest possible spin of S=11/2, and almost twice the bond length of the neutral molecule. This spin configuration can be interpreted as a result of indirect exchange coupling between the 3d electrons of the two atoms that is mediated by the single 4s electron through a strong intraatomic 3d-4s exchange interaction. Our finding allows an estimate of the relative energies of two states that are often discussed as ground-state candidates, the ferromagnetically coupled 12Σ and the low-spin 2Σ state.
J. T. Lau - One of the best experts on this subject based on the ideXlab platform.
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Electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Pi$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^8\Phi$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ transition elements cannot generally be assumed to be connected by a one-electron process.
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High orbital angular momentum quantum numbers in the electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
arXiv: Chemical Physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^6\Gamma$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.
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Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic Circular Dichroism Spectroscopy in an ion trap.
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Ławicki, M. Kossick, J. T. LauAbstract:The electronic structure and magnetic moments of free Mn2+ and Mn3+ are characterized by 2p x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results directly show that localized magnetic moments of 5 μB are created by 3d5(6S) states at each ionic core, which are coupled ferromagnetically to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly occupied 4s derived antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μB for Mn2+ and 16 μB for Mn3+, with no contribution of orbital angular momentum.
B A Wallace - One of the best experts on this subject based on the ideXlab platform.
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synchrotron radiation Circular Dichroism Spectroscopy of proteins and applications in structural and functional genomics
Chemical Society Reviews, 2006Co-Authors: Andrew Miles, B A WallaceAbstract:The technique of Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy and its advantages over conventional Circular Dichroism Spectroscopy are described in this tutorial review, as well as recent applications of the technique in structural and functional genomics. Circular Dichroism (CD) Spectroscopy is a well-established method in biological chemistry and structural biology, but its utility can be limited by the low flux of the light source in the far ultraviolet and vacuum ultraviolet wavelength regions in conventional CD instruments. The development of synchrotron radiation Circular Dichroism (SRCD), using the intense light of a synchrotron beam, has greatly expanded the utility of the method, especially as a tool for both structural and functional genomics. These applications take advantage of the enhanced features of SRCD relative to conventional CD: the ability to measure lower wavelength data containing more electronic transitions and hence more structural information, the higher signal-to-noise hence requiring smaller samples, the higher intensity enabling measurements in absorbing buffers and in the presence of lipids and detergents, and the ability to do faster measurements enabling high throughput and time-resolved Spectroscopy. This article discusses recent developments in SRCD instrumentation, software, sample preparation and methods of analyses, with particular emphasis on their applications to the study of proteins. These advances have led to new applications in structural genomics (SG), including the potential for fold recognition as a means of target selection and the examination of membrane proteins, a class of proteins usually excluded from SG programmes. Other SG uses include detection of macromolecular interactions as a screen for complex formation, and examination of glycoproteins and sugar components. In functional genomics (FG) new applications include screening for ligand binding as a means of identifying function, and examination of structural differences in mutant proteins as a means of gaining insight into function.
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synchrotron radiation Circular Dichroism Spectroscopy of proteins secondary structure fold recognition and structural genomics
Current Opinion in Chemical Biology, 2001Co-Authors: B A Wallace, Robert W JanesAbstract:Abstract Recent developments in instrumentation and bioinformatics show that the technique of synchrotron radiation Circular Dichroism Spectroscopy can provide novel information on protein secondary structures and folding motifs, and has the potential to play an important role in structural genomics studies, both as a means of target selection and as a high-throughput, low-sample-requiring screening method. This is possible because of the additional information content in the low-vacuum ultraviolet wavelength data obtainable with intense synchrotron radiation light sources, compared with that present in spectra from conventional lab-based Circular Dichroism instruments.
Akira Terasaki - One of the best experts on this subject based on the ideXlab platform.
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electronic ground states of fe2 and co2 as determined by x ray absorption and x ray magnetic Circular Dichroism Spectroscopy
Journal of Chemical Physics, 2015Co-Authors: V Zamudiobayer, K Hirsch, A Langenberg, A ławicki, Akira Terasaki, Bernd Von IssendorffAbstract:The (6)Π electronic ground state of the Co2 (+) diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, (6)Φ, (8)Φ, and (8)Γ, for the electronic ground state of Fe2 (+) have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of 3d transition elements cannot generally be assumed to be connected by a one-electron process.
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Electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Pi$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^8\Phi$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ transition elements cannot generally be assumed to be connected by a one-electron process.
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high orbital angular momentum quantum numbers in the electronic ground states of fe _2 and co _2 as determined by x ray absorption and x ray magnetic Circular Dichroism Spectroscopy
arXiv: Chemical Physics, 2015Co-Authors: V Zamudiobayer, K Hirsch, A Langenberg, Akira Terasaki, A. Lawicki, Bernd Von IssendorffAbstract:The $^6\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^6\Gamma$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.
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High orbital angular momentum quantum numbers in the electronic ground states of Fe$_2^+$ and Co$_2^+$ as determined by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy
arXiv: Chemical Physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Lawicki, J. T. LauAbstract:The $^6\Delta$ electronic ground state of the Co$_2^+$ diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap. Three candidates, $^6\Phi$, $^6\Gamma$, and $^8\Gamma$, for the electronic ground state of Fe$_2^+$ have been identified. These states carry sizable ground-state orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of $3d$ elements cannot be assumed to be connected by a one-electron process.
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Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic Circular Dichroism Spectroscopy in an ion trap.
The Journal of chemical physics, 2015Co-Authors: V. Zamudio-bayer, K Hirsch, Akira Terasaki, Bernd Von Issendorff, Andreas Langenberg, A. Ławicki, M. Kossick, J. T. LauAbstract:The electronic structure and magnetic moments of free Mn2+ and Mn3+ are characterized by 2p x-ray absorption and x-ray magnetic Circular Dichroism Spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results directly show that localized magnetic moments of 5 μB are created by 3d5(6S) states at each ionic core, which are coupled ferromagnetically to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly occupied 4s derived antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μB for Mn2+ and 16 μB for Mn3+, with no contribution of orbital angular momentum.