Local environment of metal ions in phthalocyanines: K-edge X-ray absorption spectra

2016 ◽  
Vol 18 (34) ◽  
pp. 23686-23694 ◽  
Author(s):  
G. Rossi ◽  
F. d'Acapito ◽  
L. Amidani ◽  
F. Boscherini ◽  
M. Pedio
Keyword(s):  
Metal Ions ◽  
Absorption Spectra ◽  
Local Environment ◽  
Full Potential ◽  
Metal Phthalocyanines ◽  
Potential Approach ◽  
X Ray ◽  
X Ray Absorption

We describe a model for interpreting XAFS spectra of metal phthalocyanines. The near edge spectra are reproduced in a full potential approach.

Local environment of lanthanum ions in montmorillonite upon heating

Clay Minerals ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 423-434 ◽  
Author(s):  
J. M. Trillo ◽  
M. D. Alba ◽  
M. A. Castro ◽  
A. Muñoz ◽  
J. Poyato ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Absorption Spectra ◽  
Local Environment ◽  
X Ray ◽  
Octahedral Sites ◽  
Lanthanum Ions ◽  
Structural Differences ◽  
Ft Ir ◽  
Interlamellar Region ◽  
X Ray Absorption

AbstractStructural differences which occur on heating La-montmorillonite have been studied and compared with those for montmorillonite saturated with Na(I) and Li(I). Rehydration experiments show that La-montmorillonite swells after preheating up to 500°C. However, FT-IR spectra suggest partial migration of the La(III) cations from the interlamellar region to the structural sheets and(or) deprotonation of hydrated La(III) cations, followed by migration of the resulting protons to vacant octahedral sites. Additional measurements of X-ray absorption spectra (EXAFS, XANES) and heating to 700°C suggest that interlamellar hydrated La(III) partially deprotonates producing polyoxocations.

Use of X-Ray Absorption Spectra as a “Fingerprint” of the Local Environment in Complex Chalcogenides

2000 ◽  
Vol 150 (2) ◽  
pp. 363-370 ◽  
Author(s):  
C. Branci ◽  
M. Womes ◽  
P.E. Lippens ◽  
J. Olivier-Fourcade ◽  
J.C. Jumas
Keyword(s):  
Absorption Spectra ◽  
Local Environment ◽  
X Ray ◽  
X Ray Absorption

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Theoretical description of optical and x-ray absorption spectra of MgO including many-body effects

2021 ◽  
Vol 103 (19) ◽  
Author(s):  
Vijaya Begum ◽  
Markus E. Gruner ◽  
Christian Vorwerk ◽  
Claudia Draxl ◽  
Rossitza Pentcheva
Keyword(s):  
Absorption Spectra ◽  
Theoretical Description ◽  
Many Body ◽  
X Ray ◽  
Many Body Effects ◽  
X Ray Absorption

scholarly journals Crystallographic and X-ray absorption spectroscopic characterization of Helicobacter pylori UreE bound to Ni2+ and Zn2+ reveals a role for the disordered C-terminal arm in metal trafficking

2012 ◽  
Vol 441 (3) ◽  
pp. 1017-1035 ◽  
Author(s):  
Katarzyna Banaszak ◽  
Vlad Martin-Diaconescu ◽  
Matteo Bellucci ◽  
Barbara Zambelli ◽  
Wojciech Rypniewski ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Metal Ions ◽  
Metal Binding ◽  
Metal Ion ◽  
Mutual Influence ◽  
Accurate Information ◽  
Metal Ion Binding ◽  
X Ray ◽  
X Ray Absorption

The survival and growth of the pathogen Helicobacter pylori in the gastric acidic environment is ensured by the activity of urease, an enzyme containing two essential Ni2+ ions in the active site. The metallo-chaperone UreE facilitates in vivo Ni2+ insertion into the apoenzyme. Crystals of apo-HpUreE (H. pylori UreE) and its Ni2+- and Zn2+-bound forms were obtained from protein solutions in the absence and presence of the metal ions. The crystal structures of the homodimeric protein, determined at 2.00 Å (apo), 1.59 Å (Ni2+) and 2.52 Å (Zn2+) resolution, show the conserved proximal and solvent-exposed His102 residues from two adjacent monomers invariably involved in metal binding. The C-terminal regions of the apoprotein are disordered in the crystal, but acquire significant ordering in the presence of the metal ions due to the binding of His152. The analysis of X-ray absorption spectral data obtained using solutions of Ni2+- and Zn2+-bound HpUreE provided accurate information of the metal-ion environment in the absence of solid-state effects. These results reveal the role of the histidine residues at the protein C-terminus in metal-ion binding, and the mutual influence of protein framework and metal-ion stereo-electronic properties in establishing co-ordination number and geometry leading to metal selectivity.

Electron Population Analysis by Full-Potential X-Ray Absorption Simulations

1999 ◽  
Vol 82 (11) ◽  
pp. 2398-2401 ◽  
Author(s):  
Yves Joly ◽  
Delphine Cabaret ◽  
Hubert Renevier ◽  
Calogero R. Natoli
Keyword(s):  
Population Analysis ◽  
Full Potential ◽  
Electron Population ◽  
X Ray ◽  
X Ray Absorption
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