X-ray absorption edge determination of the oxidation state and coordination number of copper. Application to the type 3 site in Rhus vernicifera laccase and its reaction with oxygen

1987 ◽  
Vol 109 (21) ◽  
pp. 6433-6442 ◽  
Author(s):  
Lung Shan Kau ◽  
Darlene J. Spira-Solomon ◽  
James E. Penner-Hahn ◽  
Keith O. Hodgson ◽  
Edward I. Solomon
Keyword(s):  
Coordination Number ◽  
Oxidation State ◽  
Absorption Edge ◽  
X Ray ◽  
Rhus Vernicifera ◽  
Type 3 ◽  
X Ray Absorption

XAFS Study of Molten ZrCl4 in LiCl-KCl Eutectic

2002 ◽  
Vol 57 (5) ◽  
pp. 277-280 ◽  
Author(s):  
Yoshihiro Okamoto ◽  
Haruhiko Motohashi
Keyword(s):  
Fine Structure ◽  
Coordination Number ◽  
Curve Fitting ◽  
Absorption Edge ◽  
Local Structure ◽  
Molten Mixture ◽  
X Ray ◽  
Absorption Fine ◽  
Curve Fitting Analysis ◽  
X Ray Absorption

The local structure of motlen ZrCl4 in LiCl-KCl eutectic was investigated by using an X-ray absorption fine structure (XAFS) of the Zr K-absorption edge. The nearest Zr4+-Cl- distance and coordination number from the curve fitting analysis were (2.51±0.02) Å and 5.9±0.6, respectively. These suggest that a 6-fold coordination (ZrCl6)2- is predominant in the molten mixture.

X-Ray Absorption-Edge Determination of Cobalt in Complex Mixtures*

1961 ◽  
Vol 5 ◽  
pp. 379-388
Author(s):  
E.A. Hakkila ◽  
G.R. Waterbury
Keyword(s):  
Nitric Acid ◽  
Absorption Edge ◽  
Path Length ◽  
Construction Materials ◽  
X Ray ◽  
Relative Standard ◽  
Standard Deviations ◽  
Low X ◽  
X Ray Absorption

AbstractThe application of the X-ray absorption-edge technique was extended to the determination of cobalt in aqueous and alcoholic solutions containing a wide variety of impurity elements. In the procedure developed, secondary radiation from a 50% copper-nickel alloy is passed through an absorption cell filled alternately with the solvent and the sample solution. The transmitted Intensities of the Kα lines for copper and nickel are measured, and the concentration of cobalt is determined using accepted absorption principles. The K absorption edge for cobalt occurs at 1.604 A, restricting cell construction materials and solvents to those containing light elements with low X-ray absorption characteristics and also limiting the path length of the cell.Cells of 0.16- and 0.34-cm path length were used in the analysis of aqueous and alcoholic solutions, respectively. With the 0.16-cm path-length cell, relative standard deviations of 4.6 to 0.5% were obtained for cobalt concentrations ranging from 1.00 to 10.00 mg/ml for known aqueous solutions that contain various known concentrations of nitric acid. With the longer path-length cell, relative standard deviations from 1.8 to 0.46% were obtained for cobalt concentrations in the same range in known alcoholic solutions containing various known concentrations of nitric acid. The standard deviation of determining the blank is 0.043 mg of cobalt per milliliter for the 0.16-cm cell and 0.016 mg of cobalt per milliliter for the longer cell.A Norelco X-ray spectrograph with a three-position head was used in these analyses. Less than 5 min is required to convert this instrument from normal fluorescence operation to absorption-edge analysis. Approximately 15 to 20 analyses can be performed daily.

Direct determination of oxidation state of gold deposits in metal-reducing bacterium Shewanella algae using X-ray absorption near-edge structure spectroscopy (XANES)

2007 ◽  
Vol 103 (6) ◽  
pp. 568-571 ◽  
Author(s):  
Yasuhiro Konishi ◽  
Takeshi Tsukiyama ◽  
Norizoh Saitoh ◽  
Toshiyuki Nomura ◽  
Shinsuke Nagamine ◽  
...  
Keyword(s):  
Oxidation State ◽  
Direct Determination ◽  
Gold Deposits ◽  
Edge Structure ◽  
X Ray ◽  
Shewanella Algae ◽  
X Ray Absorption

scholarly journals Signatures of technetium oxidation states: a new approach

2020 ◽  
Vol 56 (67) ◽  
pp. 9608-9611
Author(s):  
Stephen Bauters ◽  
Andreas C. Scheinost ◽  
Katja Schmeide ◽  
Stephan Weiss ◽  
Kathy Dardenne ◽  
...  
Keyword(s):  
Oxidation State ◽  
Oxidation States ◽  
General Strategy ◽  
New Approach ◽  
X Ray ◽  
X Ray Absorption

A general strategy for the determination of Tc oxidation state by a new approach involving X-ray absorption near edge spectroscopy (XANES) at the Tc L3 edge is shown.

EELS and Xanes Analysis of Plutonium and Cerium Edges From Titanate Ceramics for Fissile Materials Disposal

1999 ◽  
Vol 5 (S2) ◽  
pp. 768-769
Author(s):  
J.A. Fortner ◽  
E.C. Buck ◽  
A.J. Kropf ◽  
A.J. Bakel ◽  
M.C. Hash ◽  
...  
Keyword(s):  
Oxidation State ◽  
Electron Loss ◽  
Edge Structure ◽  
X Ray ◽  
Titanate Ceramics ◽  
X Ray Absorption ◽  
Photon Source ◽  
Titanate Ceramic ◽  
Exafs Spectra

We report x-ray absorption near edge structure (XANES) and extended x-ray fine structure analysis (EXAFS) spectra from the plutonium Llll and cerium Lm edges in prototype titanate ceramic hosts for disposal of surplus fissile materials. These spectra were obtained using the MRCAT beamline at the Advanced Photon Source (APS). The XANES and EXAFS results are compared with electron loss spectra (EELS) determination of oxidation state from the plutonium MlV,V and cerium MlV,V edges [1,2]. The titanate ceramics studied are based upon the hafniumpyrochlore and zirconolite mineral structures and will serve as an immobilization host, containing as much as 10 weight % fissile plutonium, and 20 weight % (natural or depleted) uranium. Similar formulations were composed using cerium as a “surrogate” element, replacing both plutonium and uranium in the ceramic matrix. We find the plutonium to be present almost entirely as Pu (IV), while the cerium is clearly in a mixed III-IV oxidation state in the surrogate ceramic.

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