A compound with severely distorted geometry at ligated carbon: synthesis and x-ray crystal structure of Bi[CH(SiMe3)2]3, a trialkylbismuth complex with high thermal stability

1983 ◽  
Vol 22 (23) ◽  
pp. 3421-3424 ◽  
Author(s):  
Brendan Murray ◽  
Jan Hvoslef ◽  
Hakon Hope ◽  
Philip P. Power
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
High Thermal Stability ◽  
X Ray ◽  
Distorted Geometry

Synthesis and structure of the ternary nitride Li6WN4

2005 ◽  
Vol 20 (1) ◽  
pp. 18-21 ◽  
Author(s):  
W. X. Yuan ◽  
J. W. Hu ◽  
Y. T. Song ◽  
W. J. Wang ◽  
Y. P. Xu
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Tetragonal System ◽  
Ternary Nitride ◽  
Stability Measurements

The ternary nitridotungstate Li6WN4 has been synthesized via the solid state reaction of lithium subnitride, Li3N, with W under nitrogen. High quality X-ray powder diffraction data were collected for the crystal-structure determination. Li6WN4 crystallizes in the tetragonal system, space group P42∕nmc, with cell parameters a=6.6759(3) Å and c=4.9280(3) Å, Z=2. Preliminary thermal stability measurements of Li6WN4 show that it is sensitive to moisture, even at room temperature, and decomposes at high temperatures below 1000 °C under flowing nitrogen.

Preparation of Anion Modified Montmorillonite-Polystyrene Nanocomposite by Suspension Polymerization

2009 ◽  
Vol 87-88 ◽  
pp. 499-503
Author(s):  
Yi Wang ◽  
Hui Xia Feng ◽  
Jian Hui Qiu
Keyword(s):  
Thermal Stability ◽  
Anionic Surfactants ◽  
Suspension Polymerization ◽  
Layered Silicate ◽  
High Thermal Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Silicate Nanocomposites ◽  
Ft Ir

To ensure good compatibility between polymer and montmorillonite (MMT), three types organophilic-MMT were prepared and the influence of modifying agent style on the modification effect was studied. The results of X-ray diffraction(XRD) show that the modified reagents are all intercalated into the galleries of MMT, which are also proved by patterns of FT-IR and thermogravimetric analysis(TGA), and the spacing of MMT layers increases from 1.23 nm of the pristine MMT to 2.10nm, 3.52nm and 4.14nm for CTAB, SDS and DBS modified MMT respectively. The results also indicate that the d-spacing and exfoliation degree of anionic surfactants inserted MMT is bigger than that of the cationic surfactants treated MMT, which are usually used to preparation polymer layered silicate nanocomposites in literatures. So PS/SDS-MMT and PS/DBS-MMT nanocomposites were prepared by suspension polymerization. The structure of complex were characterized by XRD and no peak can be observed by the spectra, which suggest that the clay platelets have been exfoliated and dispersed in the PS matrix and the both complex are all have exfoliated structure. FT-IR spectrums analysis confirmed the existence of MMT which implied that the layers of silicate was distributing in composites. The results of TGA show that nanocomposites possess exceptionally high thermal stability and the DBS treated composite has higher thermal stability than that of SDS treated.

Synthesis and structural study from X-ray powder diffraction of Pb0.5Th2(PO4)3

1997 ◽  
Vol 12 (2) ◽  
pp. 76-80 ◽  
Author(s):  
A. El-Yacoubi ◽  
R. Brochu ◽  
A. Serghini ◽  
M. Louër ◽  
M. Alami Talbi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Structural Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Thermal Stability Of

A new mixed lead thorium phosphate, Pb0.5Th2(PO4)3, has been isolated in the system PbO–ThO2–P2O5. Its crystal structure (monoclinic symmetry, a=17.459(1) Å, b=6.8451(4) Å, c=8.1438(5) Å, β=101.247(5)°, space group C2/c) has been determined from conventional monochromatic X-ray powder diffraction data. The structure is related to the MITh2(PO4)3 structure type. Lead atoms are located in the channels parallel to the c axis, out of the twofold axis for 0.97 Å, and are statistically distributed on a quarter of crystallographic positions. The thermal stability of this material is greater than that of the monazite-type compound PbTh(PO4)2.

scholarly journals Synthesis, characterization and properties of polymers containing simultaneously the imine and amide moieties.

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Christian Sánchez ◽  
Carlos Bustos ◽  
Fabiola Alvarado ◽  
Eduardo Schott ◽  
Nicolas Gatica ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Photoelectron Spectroscopy ◽  
High Thermal Stability ◽  
High Solubility ◽  
Reduced Pressure ◽  
X Ray ◽  
H Nmr ◽  
Polymeric Fraction

Abstract We present the synthesis of polymers by means of self-condensation of ethyl 3-aminophenyl acetate, using HCl as catalyst at high temperature and reduced pressure. This polymer was fractionated by successive precipitation from mixtures of methanol/diethylether of different polarity, yielding three polymeric fractions: Poly A, Poly B and Poly C. Likewise, under the same conditions, 3- aminophenyl acetic acid yields only one polymeric fraction, Poly D. These polymers were characterized by elemental analysis, IR and, in some cases, by 1H-NMR and X-Ray Photoelectron Spectroscopy (XPS). The obtained results show that polymers can be classified as hybrid materials, because in the backbone, they contain simultaneously the amide and imine groups and, at the end of the chain, they have amine and carboxylic acid functions. High solubility of some of these polymers in DMF or methanol has permitted the determination of viscosities and the preparation of films. Poly B and Poly C films exhibit amorphous morphology; and Poly D display spherullitic-type semi-crystallization pattern. The polymers can absorb solvents and they can swell up forming large-sized gels in DMF and methanol. Besides these polymers have high thermal stability that reaches a weight loss of 11.60% at 353 °C.

scholarly journals Biochemical and Structural Characterization of the Subclass B1 Metallo-β-Lactamase VIM-4

2010 ◽  
Vol 55 (3) ◽  
pp. 1248-1255 ◽  
Author(s):  
Patricia Lassaux ◽  
Daouda A. K. Traoré ◽  
Elodie Loisel ◽  
Adrien Favier ◽  
Jean-Denis Docquier ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Thermal Stability ◽  
Pseudomonas Aeruginosa ◽  
Structural Characterization ◽  
Catalytic Efficiency ◽  
X Ray ◽  
Stabilizing Effect ◽  
Loop 2

ABSTRACTThe metallo-β-lactamase VIM-4, mainly found inPseudomonas aeruginosaorAcinetobacter baumannii, was produced inEscherichia coliand characterized by biochemical and X-ray techniques. A detailed kinetic study performed in the presence of Zn2+at concentrations ranging from 0.4 to 100 μM showed that VIM-4 exhibits a kinetic profile similar to the profiles of VIM-2 and VIM-1. However, VIM-4 is more active than VIM-1 against benzylpenicillin, cephalothin, nitrocefin, and imipenem and is less active than VIM-2 against ampicillin and meropenem. The crystal structure of the dizinc form of VIM-4 was solved at 1.9 Å. The sole difference between VIM-4 and VIM-1 is found at residue 228, which is Ser in VIM-1 and Arg in VIM-4. This substitution has a major impact on the VIM-4 catalytic efficiency compared to that of VIM-1. In contrast, the differences between VIM-2 and VIM-4 seem to be due to a different position of the flapping loop and two substitutions in loop 2. Study of the thermal stability and the activity of the holo- and apo-VIM-4 enzymes revealed that Zn2+ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.

scholarly journals Crystal Structure Built from a GeO6–GeO5 Polyhedra Network with High Thermal Stability: β–SrGe2O5

2019 ◽  
Vol 1 (10) ◽  
pp. 1989-1993 ◽  
Author(s):  
Christian A. Niedermeier ◽  
Jun-ichi Yamaura ◽  
Jiazhen Wu ◽  
Xinyi He ◽  
Takayoshi Katase ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
High Thermal Stability

Synthesis, characterization, and luminescence modulation of a rare barium-tetracarboxylate framework with I2O1 connectivity

CrystEngComm ◽  
2014 ◽  
Vol 16 (37) ◽  
pp. 8706-8709 ◽  
Author(s):  
Xiao Chen ◽  
Sha He ◽  
Feiyan Chen ◽  
Yunlong Feng
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Single Crystal ◽  
Luminescence Intensity ◽  
High Thermal Stability ◽  
Solvothermal Reaction ◽  
Tetracarboxylic Acid ◽  
X Ray ◽  
Organic Framework

Solvothermal reaction of a tetracarboxylic acid with Ba(NO3)2 afforded a barium–organic framework whose single crystal X-ray structure was characterized to have I2O1 connectivity and 1 D channels 15.1 Å in diameter. This MOF has high thermal stability up to 540 °C, and its luminescence intensity can be modulated by ion exchange.

Crystal Structure, Thermoanalytical Properties and Infrared Spectra of Double Magnesium Selenates

1996 ◽  
Vol 61 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Zdeněk Mička ◽  
Lucie Prokopová ◽  
Ivana Císařová ◽  
David Havlíček
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Salts ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Thermoanalytical Studies ◽  
Thermal Stability Of

Magnesium selenates double salts K2Mg(SeO4)2.6H2O, Rb2Mg(SeO4)2.6H2O, Cs2Mg(SeO4)2.6H2O, and (NH4)2Mg(SeO4)2.6H2O have been studied by means of X-ray diffraction methods, thermoanalytical methods, and infrared spectroscopy. The basic building units of these compounds are slightly deformed tetrahedra of selenate anions and octahedra of hexaaquamagnesium(II) cations interconnected by a system of hydrogen bonds. The investigation of IR spectra has been used in the discussion of X-ray diffraction results in the field of description of the hydrogen bond system and deformation of the basic polyhedra of selenate anion and hexaaquamagnesium cation. The thermoanalytical studies are used in evaluating the effects of hydrogen bonds and polarization influence of M+ cations on thermal stability of the compounds studied.

Lanthanide(III) complex metal-organic frameworks with a phenanthroline-carboxylate derivate and 2,5-thiophenedicarboxylate coligand: hydrothermal synthesis, crystal structure, and high thermostability

2018 ◽  
Vol 73 (5) ◽  
pp. 311-317
Author(s):  
Zhao Xu ◽  
Fengqin An ◽  
Xiaohui Ma ◽  
Huiliang Zhou ◽  
Weiming Song ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Metal Organic Frameworks ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
3D Networks ◽  
Point Symbol

AbstractBased on 2-(4-carboxyphenyl)imidazo[4,5-f]-1,10-phenanthroline (HNCP) and 2,5-thiophenedicarboxylate (TDC2−) ligands, three new lanthanide-containing (Sm, Nd, and Pr) compounds, [Sm(NCP)(TDC)]n (1), [Nd(NCP)(TDC)]n·2n(H2O)0.5 (2), and [Pr(NCP)(TDC)]n·n(H2O)0.5 (3), have been synthesized using the hydrothermal method and structurally characterized using single-crystal X-ray diffraction. Structural analyses have revealed that compounds 1–3 are 3D isostructural metal-organic frameworks in which the [Ln2(COO)4] dimers can be regarded as 6-connecting nodes, and the TDC2− and NCP− ligands are simplified as connectors to achieve the double interspersed 3D networks with the point symbol {412·63}. Thermogravimetric analysis has illustrated that the rigid architecture contributes to superior thermal stability with a thermal decomposition temperature of more than 400°C for the resulting metal-organic frameworks.

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