Many attempts to obtain single crystals appropriate for X-ray diffraction analysis of the Ln(tpp)(acac) derivatives (where Ln = Gd or Sm, tpp = tetraphenylporphyrin and acac = acetylacetonate) have failed so far. A suitable way to get structural parameters for these monoporphyrinates is to use extended X-ray absorption fine structure (EXAFS) spectroscopy. We recorded spectra of the monoporphyri...

The structural properties of liquid 1-butyl-3-methylimidazolium iodide [C4mim]I have been investigated using an integrated approach that combines EXAFS spectroscopy and molecular dynamics (MD) simulations. A well defined first coordination shell composed on average of 4.5 I(-) ions around the imidazolium cation has been evidenced, and the structural arrangement of the I(-) ions has been found t...

Radioactive strontium (90Sr) is an important constituent of the complex wastes from past nuclear weapons production and has been stored in underground tanks at U.S. DOE sites (e.g., Hanford, WA). Using bulk and microfocused EXAFS spectroscopy, we examined temporal changes in solid-phase Sr speciation in kaolinite samples reacted for 1-369 d with high-pH, high ionic strength synthetic tank-waste...

In this work we present a detailed analysis of the extended x-ray absorption fine structure (EXAFS) spectra at the cobalt K-edge in a series of Co-containing polymers prepared by reaction of the Schiff-base polymer (Cl3H17N3) and a Cox2 salt. where X = NOg. CIO4. C1 and (SO4)1/2. The analysis of EXAFS data has confirmed the formation of polymericcoordination complexes as materials with a very l...

a r t i c l e i n f o a b s t r a c t The application of wavelet transform to the analysis of the extended X-ray absorption fine structure (EXAFS) from perovskite-type compounds is presented on the example of the Re L 3-edge in ReO 3 and Co K-edge in LaCoO 3. We propose a modified wavelet transform procedure, which allows better discrimination of the overlapped contributions into the EXAFS signal.

with appropriate accomodation for forward scattering (\focussing e ect") for higher shells, and inclusion of higher cumulants as necessary. The aim of data analysis is to determine the distances, coordination numbers, disorder parameters and types of atoms in the various coordination shells for the \unknown" sample. The extent to which this is possible depends on the nature of the system, the q...

In recent work, a new method for using the outputs of molecular dynamics simulations to generate enhanced inputs for EXAFS analysis of nanoparticles was reported. Although currently limited to the first coordination shell, the method was demonstrated to improve both the quality of the fit, and the cross-correlation of the EXAFS data with that from TEM and XRD. Here we discuss further the justif...

The arsenic and iron environments in different growth stages have been studied with EXAFS and XANES using Brookhaven Synchrotron Light Source. Collard Greens plants were grown and tissue samples were harvested. The project studied the EXAFS and XANES of tissue samples using As and Fe K-edges. The Fe absorption and the Fourier transform bond length information were used as a control comparison. ...

Room and liquid nitrogen temperatures Mn K-edge extended X-ray fine structure (EXAFS) studies were carried out on powder samples of ALaMnRuO6 (A = Ca, Sr, Ba) perovskites. The EXAFS analysis of Mn K-edge spectra showed MnO6 octahedra are distorted. Among the three perovskites, the polyhedral distortion is highest for SrLaMnRuO6 ( = 1.4 × 10). For CaLaMnRuO6 ( = 0.5 × 10) and BaLaMnRuO6, ( = ...

The zinc and iron environments in different growth stages have been studied with EXAFS and XANES with Brookhaven Synchrotron Light Source. Tissue samples included meat, organ, vegetable, leaf, and yeast. The project studied the EXAFS and XANES of tissue samples using Zn and Fe K-edges. Duck embryo samples show that brain and intestine would contain shorter EXFAS determined Zn-N/O bond; as with ...