scholarly journals Synchrotron Nano-Diffraction Study of Thermally Treated Asbestos Tremolite from Val d’Ala, Turin (Italy)

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 311 ◽  
Author(s):  
Carlotta Giacobbe ◽  
Jonathan Wright ◽  
Dario Di Giuseppe ◽  
Alessandro Zoboli ◽  
Mauro Zapparoli ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Risk Management ◽  
Structure Analysis ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adverse Health Effects ◽  
Nano Crystalline ◽  
Original Fibre

Nowadays, due to the adverse health effects associated with exposure to asbestos, its removal and thermal inertization has become one of the most promising ways for reducing waste risk management. Despite all the advances in structure analysis of fibers and characterization, some problems still remain that are very hard to solve. One challenge is the structure analysis of natural micro- and nano-crystalline samples, which do not form crystals large enough for single-crystal X-ray diffraction (SC-XRD), and their analysis is often hampered by reflection overlap and the coexistence of multiple fibres linked together. In this paper, we have used nano-focused synchrotron X-rays to refine the crystal structure of a micrometric tremolite fibres from Val d’Ala, Turin (Italy) after various heat treatment. The structure of the original fibre and after heating to 800 °C show minor differences, while the fibre that was heated at 1000 °C is recrystallized into pyroxene phases and cristobalite.

scholarly journals X-ray crystal structure of a malonate-semialdehyde dehydrogenase fromPseudomonassp. strain AAC

2017 ◽  
Vol 73 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Matthew Wilding ◽  
Colin Scott ◽  
Thomas S. Peat ◽  
Janet Newman
Keyword(s):  
Crystal Structure ◽  
Search Model ◽  
Molecular Replacement ◽  
X Rays ◽  
X Ray Diffraction ◽  
Acetyl Coa ◽  
Space Group ◽  
X Ray ◽  
Semialdehyde Dehydrogenase

The NAD-dependent malonate-semialdehyde dehydrogenase KES23460 fromPseudomonassp. strain AAC makes up half of a bicistronic operon responsible for β-alanine catabolism to produce acetyl-CoA. The KES23460 protein has been heterologously expressed, purified and used to generate crystals suitable for X-ray diffraction studies. The crystals belonged to space groupP212121and diffracted X-rays to beyond 3 Å resolution using the microfocus beamline of the Australian Synchrotron. The structure was solved using molecular replacement, with a monomer from PDB entry 4zz7 as the search model.

scholarly journals E. S. Fedorov Promoting the Russian-German Scientific Interrelationship

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181 ◽  
Author(s):  
Peter Paufler ◽  
Stanislav K. Filatov
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystalline State ◽  
Crystal Structure Analysis ◽  
Present Knowledge ◽  
Personal Contact ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Impact

At the dawn of crystal structure analysis, the close personal contact between researchers in Russia and Germany, well documented in the “Zeitschrift für Krystallographie und Mineralogie”, contributed significantly to the evolution of our present knowledge of the crystalline state. The impact of the Russian crystallographer E. S. Fedorov upon German scientists such as A. Schoenflies and P. Groth and the effect of these contacts for Fedorov are highlighted hundred years after the death of the latter. A creative exchange of ideas paved the way for the analysis of crystal structures with the aid of X-ray diffraction.

Metallkomplexe mit funktionalisierten Schwefelliganden, X [1] Ruthenium(II)-und Platin(II)-1-alkin-1-thiolato-Komplexe. Kristallstrukturanalyse von trans-(Ph3P)2Pt[S-C≡C-C(CH3)3]2 / Metal Complexes of Functionalized Sulfur Containing Ligands, X [1] Synthesis of Ruthenium (II) and Platinum(II) 1-Alkyne-1-thiolato Complexes. X-Ray Structure Analysis of trans-( Ph3P)2Pt[C-C≡C-C(CH3)3]2

1996 ◽  
Vol 51 (4) ◽  
pp. 501-505 ◽  
Author(s):  
Wolfgang Weigand ◽  
Michael Weishäupl ◽  
Christian Robl
Keyword(s):  
Crystal Structure ◽  
Metal Complexes ◽  
Structure Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfur Containing

Abstract The 1-alkyne-1-thiolates R-C ≡C-SLi [1a: R = C(CH3)3, 1b: R = C6H11 ] react with L2PtCl2 (L = PPh3, 1/2 dppe) and CpRu(PPh3)2Cl, respectively to give the complexes trans-(Ph3P)2Pt[S-C ≡C-C(CH3)3]2 (2a), cis-dppePt[S-C≡C-C(CH3)3]2 (2b), and CpRu(PPh3)2-(S-C ≡ C-R) [3a: R = C(CH3)3, 3b: R = C6H11]. 2a has been characterized by 31P CP/MAS NM R spectroscopy and its crystal structure determined by X-ray diffraction.

scholarly journals A Salt Metathesis Route To Ruthenium Carbene Complex Isomers With Pyridine Dicarboxamide-Derived Chelate Pincer Ligands

2007 ◽  
Vol 62 (6) ◽  
pp. 783-790 ◽  
Author(s):  
Carolin Wallenhorst ◽  
Kirill V. Axenov ◽  
Joseph S. M. Samec ◽  
Roland Fröhlich ◽  
Gerhard Erker
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Pincer Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbene Complex ◽  
Related Complex

Reaction of the doubly deprotonated pyridine 2,6-dicarboxamido ligand (1) with (PCy3)2Cl2 Ru=CHPh (3a) in THF gave a mixture of (lig)(PCy3)Ru=CHPh isomers (4). The pentane soluble N,N,O-4 isomer was isolated by extraction and characterized by X-ray diffraction. The O,N, O-4 isomer was identified in the residue. Single crystals of the closely related complex (lig)(NHC) Ru=CHPh, O,N,O-5, were obtained from the reaction of 1 with (NHC)(PCy3)Cl2Ru=CHPh (3b) and used for the X-ray crystal structure analysis of the system

Structure Analysis of a Rodlike Macromolecule: Poly(2,2'-(p,p'-Biphenyl)−6,6'-bis(4-Phenylquinoline))

1988 ◽  
Vol 134 ◽  
Author(s):  
Craig W. Burkhart ◽  
Jerome B. Lando ◽  
John K. Stille
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Molecular Packing ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fiber Diffraction ◽  
Herringbone Structure ◽  
Packing Analysis

ABSTRACTUniaxially oriented, crystalline fibers of poly(2,2'-(p,p'-biphenyl)- 6,6'-bis(4-phenylquinoline)) [PBPQ], were subjected to structure analysis via x-ray diffraction and molecular packing analysis. Packing analysis was required due to the sparse and diffuse nature of the fiber diffraction photographs. The combination of the two techniques allowed us to resolve the crystal structure. PBPQ packs in a syn conformation, in a modified herringbone structure. It has a unit cell of a = 16.2Å, b = 5.31Å, c = 21.4Å. There are two independent chains in the unit cell. An overview of the refinement of the crystal structure, the packing analysis and the crystallography are presented.

Crystal structure analysis of molecular dynamics using synchrotron X-rays

CrystEngComm ◽  
2015 ◽  
Vol 17 (46) ◽  
pp. 8786-8795 ◽  
Author(s):  
Manabu Hoshino ◽  
Shin-ichi Adachi ◽  
Shin-ya Koshihara
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
X Rays ◽  
X Ray ◽  
X Ray Crystallography

X-ray crystallography using synchrotron X-rays enables observation of molecular dynamics in a crystal.

Synthesis of Novel Chromium Oxide Using Hydrothermal Method and Analysis of its Magnetism and Structure

2011 ◽  
Vol 170 ◽  
pp. 29-32
Author(s):  
Shintaro Ogawa ◽  
Koji Okuta ◽  
Hirohiko Sato
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
High Temperature ◽  
Hydrothermal Method ◽  
Layered Structure ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Glass Behavior ◽  
Glass Behavior

We have discovered a novel compound Na0.12CrO2Ge0.18Ox•yH2O using a hydrothermal method. Its powder X-ray diffraction reveals a monoclinic unit cell with lattice parameters: a = 7.260 Å, b = 2.950 Å, c = 5.117 Å and β = 103.7°. A Rietveld analysis shows that this compound has a layered structure based on CrO2 sheets consisting of edge-shared CrO6 octahedra. Such a layered structure is commonly seen in many hexagonal Cr oxides such as NaCrO2. A heat treatment at 100 °C modifies the crystal structure without destruction of a layered structure based on Cr triangular-lattice, because H2O molecules among the CrO2 sheets are removed at high temperature. Magnetization measurements reveal a spin-glass behavior below Tg = 3 K.

A Re-investigation of the Crystal Structure of the Perovskite PbZrO3 by X-ray and Neutron Diffraction

1997 ◽  
Vol 53 (1) ◽  
pp. 135-142 ◽  
Author(s):  
D. L. Corker ◽  
A. M. Glazer ◽  
J. Dec ◽  
K. Roleder ◽  
R. W. Whatmore
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Lead Zirconate ◽  
Conclusive Evidence ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Investigations

The crystal structure of the perovskite lead zirconate PbZrO3 has been redetermined using single-crystal X-ray diffraction (Mo Kα radiation, λ = 0.71069 Å). Single-crystal data at 100 K: space group. Pbam, a = 5.884 (1), b = 11.787 (3), c = 8.231 (2) Å, V = 570.85 Å3 with Z = 8, μ = 612.6 cm−1, D x = 8.06 Mg m−3, F(000) = 1168, final R = 0.033, wR = 0.061 over 555 reflections with I > 2σ(I). An investigation is made into previous contradicting reports of a possible disorder in the O atoms and their origin by examining the crystal pseudo-symmetry. Information distinguishing an ordered and disordered oxygen substructure is shown to reside in weak l odd reflections. Because of their extremely low intensities these reflections have not contributed sufficiently in previous X-ray structure investigations and hence, to date, conclusive evidence differentiating between ordered and disordered models has not been possible. By collecting single-crystal X-ray data at low temperature and by using exceptionally long scans on selected hkl, l odd, reflections, a new accurate structure determination is presented and discussed, showing the true ordered oxygen positions. Because of the large difference in scattering factors between lead and oxygen when using X-rays, a neutron diffraction Rietveld refinement using polycrystalline samples (D1A instrument, ILL, λ = 1.90788 Å) is also reported as further evidence to support the true ordered oxygen structure revealed by the low-temperature X-ray analysis.

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