A systematic x-ray absorption study of molybdenum complexes. The accuracy of structural information from extended x-ray absorption fine structure

1978 ◽  
Vol 100 (9) ◽  
pp. 2748-2761 ◽  
Author(s):  
Stephen P. Cramer ◽  
Keith O. Hodgson ◽  
Edward I. Stiefel ◽  
William E. Newton
1977 ◽  
Vol 55 (11) ◽  
pp. 1968-1974 ◽  
Author(s):  
E. D. Crozier ◽  
F. W. Lytle ◽  
D. E. Sayers ◽  
E. A. Stern

The extended fine structure in the X-ray absorption coefficient is dominated by the interference of the photoelectron scattered by atoms in the immediate neighbourhood of the atom which absorbs the X-ray photon and thus can provide structural information about ordered or disordered systems. In this paper it is demonstrated that Extended X-Ray Absorption Fine Structure (EXAFS) measurements can be made on liquid systems at high temperatures. The technique is illustrated with results for As2Se3 in the liquid and amorphous states for temperatures between 100 and 773 K. A Fourier analysis of the EXAFS data reveals that a major structural rearrangement does not occur in the nearest neighbour shell when As2Se3 is melted. However, small structural changes do occur at the melting point which, within the limitations of the present data, suggest a slight increase in the nearest neighbour As–Se distance, a decrease in the number of nearest neighbours, and a decrease in the nearest neighbour disorder term σ12.


1984 ◽  
Vol 221 (2) ◽  
pp. 545-548 ◽  
Author(s):  
S S Hasnain ◽  
G P Diakun ◽  
P F Knowles ◽  
N Binsted ◽  
C D Garner ◽  
...  

Copper K-edge e.x.a.f.s (extended X-ray-absorption fine structure) was measured for dopamine beta-mono-oxygenase in aqueous solution. Comparison with the Cu K-edge e.x.a.f.s. of bovine erythrocyte superoxide dismutase shows a close resemblance. Detailed analysis of the e.x.a.f.s. indicates that the copper atom is bound to four imidazole groups at 0.201 nm with one or two oxygen atoms at 0.23 nm.


2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Wolfgang Grünert ◽  
Konstantin Klementiev

AbstractThe X-ray Absorption Fine Structure (XAFS) with its subregions X-ray Absorption Near-edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) is a powerful tool for the structural analysis of materials, which is nowadays a standard component of research strategies in many fields. This review covers a wide range of topics related to its measurement and use: the origin of the fine structure, its analytical potential, derived from the physical basis, the environment for measuring XAFS at synchrotrons, including different measurement geometries, detection modes, and sample environments, e. g. for in-situ and operando work, the principles of data reduction, analysis, and interpretation, and a perspective on new methods for structure analysis combining X-ray absorption with X-ray emission. Examples for the application of XAFS have been selected from work with heterogeneous catalysts with the intention to demonstrate the strength of the method providing structural information about highly disperse and disordered systems, to illustrate pitfalls in the interpretation of results (e. g. by neglecting the averaged character of the information obtained) and to show how its merits can be further enhanced by combination with other methods of structural analysis and/or spectroscopy.


2009 ◽  
Vol 81 (7) ◽  
pp. 1323-1330 ◽  
Author(s):  
Kyosuke Domae ◽  
Daisuke Uchimura ◽  
Yuuki Koyama ◽  
Shinnosuke Inami ◽  
Yoshihito Hayashi ◽  
...  

A new route to an alkoxohexavanadate species leads to the isolation of a bowl-type dodecavanadate without a guest molecule in the cavity. The 1D tetravanadate, [V4O11]2-, is a good precursor for the alkoxohexavanadate, [V6O13(OCH3)6]2-, which is then utilized for the [V6 + V6] coupling reaction to form the dodecavanadate, [V12O42]4-, with a capped dichloromethane molecule at the cavity entrance. We also obtained structural information on a newly discovered octadecavanadate,  [V18O46(NO3)]5-,in both the solid and solution states through extended X-ray absorption fine structure (EXAFS) studies. The existence of a chiral inorganic species in acetonitrile with double-stranded V8 chains was confirmed through EXAFS oscillations.


2000 ◽  
Vol 454-456 ◽  
pp. 723-728 ◽  
Author(s):  
H. Magnan ◽  
P. Le Fèvre ◽  
A. Midoir ◽  
D. Chandesris ◽  
H. Jaffrès ◽  
...  

Author(s):  
Kazumasa Murata ◽  
Junya Ohyama ◽  
Atsushi Satsuma

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed using in situ X-ray absorption fine structure (XAFS) spectroscopy.


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