L-edge x-ray-absorption systematics of the noble metals Rh, Pd, and Ag and the main-group metals In and Sn: A study of the unoccupied density of states in 4delements

1985 ◽  
Vol 31 (4) ◽  
pp. 1888-1902 ◽  
Author(s):  
T. K. Sham
Keyword(s):  
Density Of States ◽  
Noble Metals ◽  
Main Group ◽  
X Ray ◽  
Main Group Metals ◽  
X Ray Absorption

In situ XANES Study of Co2+ Ion Adsorption on Fe3O4 Nanoparticles in Supercritical Aqueous Fluids

2012 ◽  
Vol 1383 ◽  
Author(s):  
Hao Yan ◽  
Robert A. Mayanovic ◽  
Joseph Demster ◽  
Alan J. Anderson
Keyword(s):  
Angular Momentum ◽  
Density Of States ◽  
Fe3o4 Nanoparticles ◽  
Ion Adsorption ◽  
Edge Structure ◽  
X Ray ◽  
Peak Fitting ◽  
X Ray Absorption ◽  
In Situ Xanes

ABSTRACTIn situ x-ray absorption spectroscopy (XAS) measurements were made on Fe3O4 nanoparticles in supercritical aqueous fluids to 500 °C in order to study their reactivity with Co2+ aqua ions and to investigate the structural properties of the reacted nanoparticles. The analyses of the x-ray absorption near edge structure (XANES) of XAS indicate that reactivity of Fe3O4 nanoparticles with Co2+ ions is minimal to 200 °C but becomes significant in the 250–500 °C temperature range. XANES and angular momentum projected density of states (l-DOS) calculations were carried out using the FEFF8.2 code and analyses were made using multi-peak fitting to determine the origin of the features exhibited in the spectra.

Unoccupied density of states ofLa2−xSrxNiO4+δstudied by polarization-dependent x-ray-absorption spectroscopy and bremsstrahlung isochromat spectroscopy

1991 ◽  
Vol 44 (9) ◽  
pp. 4570-4575 ◽  
Author(s):  
P. Kuiper ◽  
J. van Elp ◽  
G. A. Sawatzky ◽  
A. Fujimori ◽  
S. Hosoya ◽  
...  
Keyword(s):  
Density Of States ◽  
Absorption Spectroscopy ◽  
X Ray ◽  
X Ray Absorption

STUDY OF ELECTRONIC STRUCTURE OF MgB2 BY MULTIPLE-SCATTERING CALCULATIONS OF B K-EDGE XANES

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1605-1612
Author(s):  
ZIYU WU ◽  
N. L. SAINI ◽  
A. BIANCONI
Keyword(s):  
Multiple Scattering ◽  
Density Of States ◽  
Core Hole ◽  
Edge Structure ◽  
X Ray ◽  
The Core ◽  
Al Substitution ◽  
Band Structure Calculations ◽  
X Ray Absorption ◽  
Structure Calculations

The MgB 2 system is studied by self consistent multiple-scattering calculations at the B K-edge X-ray absorption near edge structure (XANES). We find that the features in the B K-edge XANES are strongly affected by medium and long range order with large influence of the core hole potential suggesting that the band structure calculations are not enough to provide a quantitative interpretation of the spectral features. We have investigated evolution of density of states in the conduction band as a function of Al substitution in place of the Mg. The results are consistent with the fact that the Al substitution influences mainly the density of states in the B σ-band and hence suppresses the superconductivity.

Electronic structure of twisted and planar rubrene molecules: a density functional study

2018 ◽  
Vol 20 (27) ◽  
pp. 18623-18629 ◽  
Author(s):  
T. Mukherjee ◽  
Sumona Sinha ◽  
M. Mukherjee
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Of States ◽  
Electron Density Distribution ◽  
Density Functional ◽  
Functional Study ◽  
Functional Theory ◽  
X Ray ◽  
Homo And Lumo ◽  
X Ray Absorption

X-ray absorption spectra (XAS), the density of states (DOS) and the electron density distribution of the HOMO and LUMO for flat and twisted rubrene molecules have been calculated using density functional theory (DFT).

scholarly journals Zur Koordination unterschiedlicher Hauptgruppenmetalle mit einem speziellen, chelatisierenden Silazan / On the Coordination of Different Main Group Metals with a Special, Chelating Silazane

1988 ◽  
Vol 43 (7) ◽  
pp. 846-856 ◽  
Author(s):  
M. Veith ◽  
F. Goffing ◽  
V. Huch
Keyword(s):  
Nmr Spectra ◽  
Main Group ◽  
High Symmetry ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Main Group Metals ◽  
H Nmr ◽  
Structure Determinations ◽  
Cis Isomer

Abstract The cis-isomer of the silazane H2L (1) (L = [NtBu][Me]Si(NtBu)2Si[Me][NtBu]) has been used as a ligand to main group metals. By displacing the hydrogen atoms of 1 the compounds L(MgMe)2 (4), L(MgCl)2 (5) and L(Li)(InMe2) (6) have been obtained. According to the 1H NMR spectra the structures of 4-6 are very similar: a polycyclic, cubane-like Si2N4M2 framework results from the special atomic arrangements and from intramolecular Lewis acid-base interactions between the metals M and the nitrogen atoms. Divalent metals and metal-centered groups can also be incorporated into 1. In the latter case a seco norcubane-like polycycle Si2N4M is produced as confirmed by X-ray structure determinations of LGaMe (8) and LSb+ InCl4- (11). LInMe (7) and LSn (9) seem to adopt the same tricyclic structure as 8, although the 1H NMR spectra are not consistent with a rigid molecule (low symmetry), but rather with a fluxional behaviour (high symmetry). When 5 is allowed to react with sodium/naphthalene in THF part of the magnesium is reduced and LMg(THF)2 (12) is formed. An X-ray structure determination of 12 reveals the compound to be only bicyclic with the magnesium atom coordinated by two nitrogen and two THF oxygen atoms.

scholarly journals Alignment of valence photoemission, x-ray absorption, and substrate density of states for an adsorbate on a semiconductor surface

2003 ◽  
Vol 67 (23) ◽  
Author(s):  
J. Schnadt ◽  
J. N. O’Shea ◽  
L. Patthey ◽  
J. Krempaský ◽  
N. Mårtensson ◽  
...  
Keyword(s):  
Density Of States ◽  
Semiconductor Surface ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Connecting Main-Group Metals (Al, Ga, In) and Tungsten(0) Carbonyls via the N2S2 Metallo-Ligand Strategy

Inorganics ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 115
Author(s):  
Xuemei Yang ◽  
Allen Lunsford ◽  
Marcetta Y. Darensbourg
Keyword(s):  
Transition Metals ◽  
Mass Spectra ◽  
Main Group ◽  
Bimetallic Complexes ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Group Iii ◽  
Main Group Metals ◽  
Square Planar

Tetradentate N2S2 ligands (such as bismercaptoethanediazacycloheptane in this study) have seen extensive use in combination with transition metals. Well-oriented N2S2 binding sites are ideal for d8 transition metals with square planar preferences, especially NiII, but also as a square pyramidal base for those metals with pentacoordinate preferences, such as [V≡O]2+, [Fe(NO)]2+, and [Co(NO)]2+. Further reactivity at the thiolate sulfurs generates diverse bi, tri, and tetra/heterometallic compounds. Few N2S2 ligands have been explored to investigate the possibility of binding to main group metals, especially group III (MIII) metals, and their utility as synthons for main group/transition metal bimetallic complexes. To open up this area of chemistry, we synthesized three new five-coordinate main group XMN2S2 complexes with methyl as the fifth binding ligand for M = Al, and chloride for M = Ga and In. The seven-membered diazacycle, dach, was engaged as a rigid stabilized connector between the terminal thiolate sulfurs. The pentacoordinate XMN2S2 complexes were characterized by 1H-NMR, 13C-NMR, +ESI-Mass spectra, and X-ray diffraction. Their stabilities and reactivities were probed by adding NiII sources and W(CO)5(THF). The former replaces the main group metals in all cases in the N2S2 coordination environment, demonstrating the weak coordinate bonds of MIII–N/S. The reaction of XMN2S2 (XM = ClGaIII or ClInIII) with the labile ligand W(0) complex W(CO)5(THF) resulted in Ga/In–W bimetallic complexes with a thiolate S-bridge. The synthesis of XMN2S2 complexes provide examples of MIII–S coordination, especially Al–S, which is relatively rare. The bimetallic Ga/In–S–W complex formation indicates that the nucleophilic ability of sulfur is retained in MIII–S–R, resulting in the ability of main group MIII–N2S2 complexes to serve as metalloligands.

Sign in / Sign up

Export Citation Format

Share Document