Vibrational Studies of X-Ray Molecular Form Factors and Intensities

1980 ◽  
pp. 549-568
Author(s):  
Joel Epstein ◽  
Robert F. Stewart
Keyword(s):  
Molecular Form ◽  
Form Factors ◽  
X Ray ◽  
Vibrational Studies

scholarly journals Molecular form factors in X-ray crystallography

1969 ◽  
Vol 25 (3) ◽  
pp. 444-450 ◽  
Author(s):  
P. P. M. Groenewegen ◽  
D. Feil
Keyword(s):  
Molecular Form ◽  
Form Factors ◽  
X Ray ◽  
X Ray Crystallography

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

2019 ◽  
Author(s):  
Evan Gardner ◽  
Caitlyn Cobb ◽  
Jeffery A. Bertke ◽  
Timothy H. Warren
Keyword(s):  
Single Crystal ◽  
Copper Hydroxide ◽  
X Ray ◽  
Modular Synthesis ◽  
Pendant Arm ◽  
Copper Center ◽  
Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands <sup>XpyMe</sup>TpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>(<b>6a</b><b>–6e</b>) complexes were synthesized from the corresponding <sup>XpyMe</sup>TpCu–OAc (<b>5a–5e</b>) complexes. Single crystal X-ray structures of three new dinuclear [<sup>XpyMe</sup>TpCu]<sub>2</sub>(𝜇–OH)<sub>2</sub>complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric <sup>DMAPMe</sup>TpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈<sub>OH </sub>frequencies that tracks with the H-bond accepting ability of the pendant arm.

scholarly journals Structural and Raman Vibrational Studies ofCeO2-Bi2O3Oxide System

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
L. Bourja ◽  
B. Bakiz ◽  
A. Benlhachemi ◽  
M. Ezahri ◽  
J. C. Valmalette ◽  
...  
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Phase Changes ◽  
Phase System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vibrational Studies ◽  
Coprecipitation Route

A series of ceramics samples belonging to theCeO2-Bi2O3phase system have been prepared via a coprecipitation route. The crystallized phases were obtained by heating the solid precursors at600∘Cfor 6 hours, then quenching the samples. X-ray diffraction analyses show that forx<0.20a solid solutionCe1−xBixO2−x/2with fluorine structure is formed. For x ranging between 0.25 and 0.7, a tetragonalβ′phase coexisting with the FCC solid solution is observed. For x ranging between 0.8 and 0.9, a new tetragonalβphase appears. Theβ′phase is postulated to be a superstructure of theβphase. Finally, close tox=1, the classical monoclinicα Bi2O3structure is observed. Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.

FitGISAXS: software package for modelling and analysis of GISAXS data using IGOR Pro

2010 ◽  
Vol 43 (4) ◽  
pp. 929-936 ◽  
Author(s):  
David Babonneau
Keyword(s):  
Software Package ◽  
Form Factors ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Scattering Data ◽  
Stratified Medium ◽  
X Ray ◽  
X Ray Scattering ◽  
Structure Factors ◽  
Scripting Language

A software package for performing modelling and analysis of GISAXS (grazing-incidence small-angle X-ray scattering) data within the distorted-wave Born approximation has been developed using the IGOR Pro scripting language (http://www.wavemetrics.com). The tool suite uses a slab-model approach with the Abélès matrix method to calculate X-ray reflectivity curves, electric field intensity distributions and GISAXS intensities from supported or buried scatterers arranged in two or three dimensions in a stratified medium. Models are included to calculate the scattered intensity for monodisperse, polydisperse and interacting particles with various size distributions, form factors and structure factors. The source code for the entire package is freely available, allowing anyone to develop additional tools.

X-ray Scattering Factors of Ions in Crystals

1979 ◽  
Vol 34 (12) ◽  
pp. 1471-1481 ◽  
Author(s):  
P. C. Schmidt ◽  
Alarich Weiss
Keyword(s):  
Gaseous Phase ◽  
Form Factors ◽  
Negative Ions ◽  
X Rays ◽  
Charged Sphere ◽  
Sphere Model ◽  
X Ray ◽  
Hartree Fock ◽  
X Ray Scattering ◽  
Atomic Scattering

AbstractThe atomic scattering factors for X - Rays are given for the ions Li⊕, Be2⊕, B3⊕, C4⊕, N5⊕, N3⊖, O2⊖, F⊖, Na⊕, Mg2⊕, Al3⊕, S2⊖, Cl⊖, K⊕, Ca2⊕, Sc3⊕, Ti4⊕, V5⊕, Ni, Cu⊕, Zn2⊕, Ga3⊕, Se2⊖, Br⊖, Rb⊕, Sr2⊕, Y3⊕, Pd, Ag⊕, Cd2⊕, I⊖, Cs⊕, and Ba2⊕ in the crystal. The crystal potential is simulated by a hollow charged sphere (Watson sphere model). The Hartree-Fock-Roothaan-method was used for the calculation. The crystal field affects most strongly the atomic form factors of the negative ions, especially the twofold and threefold ionized negative ions, which are unstable in the gaseous phase.

scholarly journals Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Florian Massuyeau ◽  
Liliana Violeta Constantin ◽  
Adrian Costescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Textural Properties ◽  
Average Crystallite Size ◽  
Luminescent Properties ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vibrational Studies ◽  
20 Nm

The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca10−xEux(PO4)6(OH)2) with0≤x≤0.2nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic5D0→7F0transition observed at 578 nm related to Eu3+ions distributed on Ca2+sites of the apatitic structure.

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