X-ray Absorption and EPR Studies on the Copper Ions Associated with the Particulate Methane Monooxygenase fromMethylococcus capsulatus(Bath). Cu(I) Ions and Their Implications

1996 ◽  
Vol 118 (50) ◽  
pp. 12766-12776 ◽  
Author(s):  
Hiep-Hoa T. Nguyen ◽  
Kent H. Nakagawa ◽  
Britt Hedman ◽  
Sean J. Elliott ◽  
Mary E. Lidstrom ◽  
...  
Keyword(s):  
Copper Ions ◽  
Methane Monooxygenase ◽  
Particulate Methane Monooxygenase ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Towards a unified understanding of the copper sites in particulate methane monooxygenase: An X-ray absorption spectroscopic investigation

2021 ◽  
Author(s):  
George Cutsail III ◽  
Matthew O Ross ◽  
Amy C Rosenzweig ◽  
Serena DeBeer
Keyword(s):  
Greenhouse Gas ◽  
Spectroscopic Investigation ◽  
Liquid Fuel ◽  
Methane Monooxygenase ◽  
Enzymatic Conversion ◽  
Particulate Methane Monooxygenase ◽  
X Ray ◽  
Mild Conditions ◽  
Copper Sites ◽  
X Ray Absorption

The enzymatic conversion of the greenhouse gas, methane, to a liquid fuel, methanol, is performed by methane monooxygenases (MMOs) under mild conditions. The copper stoichiometry of particulate MMO (pMMO) has...

scholarly journals Characterization of the Particulate Methane Monooxygenase Metal Centers in Multiple Redox States by X-ray Absorption Spectroscopy

2006 ◽  
Vol 45 (20) ◽  
pp. 8372-8381 ◽  
Author(s):  
Raquel L. Lieberman ◽  
Kalyan C. Kondapalli ◽  
Deepak B. Shrestha ◽  
Amanda S. Hakemian ◽  
Stephen M. Smith ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Methane Monooxygenase ◽  
Particulate Methane Monooxygenase ◽  
Metal Centers ◽  
X Ray ◽  
Redox States ◽  
X Ray Absorption

scholarly journals High-Energy-Resolution Fluorescence-Detected X-ray Absorption of the Q Intermediate of Soluble Methane Monooxygenase

2017 ◽  
Vol 139 (49) ◽  
pp. 18024-18033 ◽  
Author(s):  
Rebeca G. Castillo ◽  
Rahul Banerjee ◽  
Caleb J. Allpress ◽  
Gregory T. Rohde ◽  
Eckhard Bill ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Methane Monooxygenase ◽  
High Energy ◽  
High Energy Resolution ◽  
X Ray ◽  
Soluble Methane Monooxygenase ◽  
X Ray Absorption

LiMn2-xCuxO4 Spineis - 5 V Cathode Materials

1997 ◽  
Vol 496 ◽  
Author(s):  
Yair Ein-Eli ◽  
W. F. Howard ◽  
Sharon H. Lu ◽  
Sanjeev Mukerjee ◽  
James McBreen ◽  
...  
Keyword(s):  
Copper Ions ◽  
Oxide Phase ◽  
Electrochemical Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Compounds ◽  
Composition And Structure ◽  
Phase Spinel ◽  
Lithium Copper Oxide ◽  
X Ray Absorption

ABSTRACTA series of electroactive spinel compounds, LiMn2-xCuxO4 (0.1 ≤ x ≤ 0.5) has been studied by crystallographic, spectroscopie and electrochemical methods and by electron-microscopy. These LiMn2-xCuxO4 spinels are nearly identical in structure to cubic LiMn2O4 and successfully undergo reversible Li intercalation. The electrochemical data show slight shifts to higher voltage for the delithiation reaction that normally occurs at 4.1 V in standard Li1−xMn2O4 electrodes (1 ≥ x ≥ 0) corresponding to the oxidation of Mn3+ to Mn4+. The data also show a remarkable reversible electrochemical process at 4.9 V which is attributed to the oxidation of Cu2+ to Cu3+. The inclusion of Cu in the spinel structure enhances the electrochemical stability of these materials upon cycling. The initial capacity of LiMn2-xCuxO4 spinels decreases with increasing x from 130 mAh/g in LiMn2O4 (x=0) to 70 mAh/g in “LiMn1.5Cu0.5O4”(x=0.5). Although the powder X-ray diffraction pattern of “LiMn1.5Cu0.5 O4” shows a single-phase spinel product, neutron diffraction data show a small, but significant quantity of an impurity phase, the composition and structure of which could not be identified. X-ray absorption spectroscopy was used to gather information about the oxidation states of the manganese and copper ions. The composition of the spinel component in the LiMn1.5Cu0.5O4 was determined from X-ray diffraction and XANES data to be Li1.01Mn1.67Cu0.32O4 suggesting, to a best approximation, that the impurity in the sample was a lithium-copper-oxide phase.

VALENCE STATES AND LOCAL ENVIRONMENT OF THALLIUM AND COPPER IONS IN SOME NEW HIGH Tc SUPERCONDUCTORS BY XAS

1989 ◽  
Vol 03 (07) ◽  
pp. 1085-1096 ◽  
Author(s):  
F. STUDER ◽  
R. RETOUX ◽  
C. MARTIN ◽  
C. MICHEL ◽  
B. RAVEAU ◽  
...  
Keyword(s):  
Valence State ◽  
Copper Ions ◽  
Local Environment ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Valence States ◽  
X Ray Absorption ◽  
Thallium Ions

The valence states of cations inside four high T c thallium superconductors have been investigated by X-ray absorption spectroscopy at thallium LIII , LI and copper K-edges. The thallium ions are observed on LIII and LI edges in the Tl(III) valence state (empty 6s levels) in spite of large Tl-O distances in the (a, b) plane of the structure as deduced from X-ray diffraction. The presence of two types of Tl-O distances have been well established on XANES spectra and the F.T. of EXAFS have shown the presence of two very short Tl-O bonds (2.03 Å). The copper K-edges are characterized by the absence of Cu(I) state (3d10 line).

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