Chemical Bonding Specifics of Hybrid Metal-Polymer Nanocomposites Based on Cobalt Nanoparticles and Polyacrylonitrile: X-Ray Spectroscopy Investigation

2016 ◽  
Vol 257 ◽  
pp. 175-178 ◽  
Author(s):  
Galina Yalovega ◽  
Tatiana Semenistaya
Keyword(s):  
Double Bond ◽  
Porous Structure ◽  
Polymer Nanocomposites ◽  
Chemical Bonding ◽  
Triple Bond ◽  
Cobalt Nanoparticles ◽  
Polymer Backbone ◽  
X Ray ◽  
Ir Pyrolysis ◽  
Metal Polymer

The cobalt-containing polyacrylonitrile (PAN) films were fabricated using IR-pyrolysis under low vacuum conditions. It was found that Co/PAN films have a porous structure and cobalt nanoparticles with size 0.1-0.2 μm embedded into PAN matrix. Besides, as a result of interaction between PAN matrix and Co ions unsaturation in the polymer backbone is observed caused by the transformation of the C≡N triple bond to a C=N double bond. At the same time formation of Co-N bond is observed.

Metal-polymer nanocomposites based on polydiphenylamine and cobalt nanoparticles

2013 ◽  
Vol 8 (7-8) ◽  
pp. 452-460 ◽  
Author(s):  
S. Zh. Ozkan ◽  
E. L. Dzidziguri ◽  
P. A. Chernavskii ◽  
G. P. Karpacheva ◽  
M. N. Efimov ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Cobalt Nanoparticles ◽  
Metal Polymer

Ca4Ni3C5, a Carbide with an One-Dimensionally Infinite Nickel-Carbon Polyanion, and CaPd3C, a Perovskite Carbide

1991 ◽  
Vol 46 (9) ◽  
pp. 1177-1182 ◽  
Author(s):  
Uwe E. Musanke ◽  
Wolfgang Jeitschko
Keyword(s):  
Chemical Bonding ◽  
Perovskite Structure ◽  
Triple Bond ◽  
The Other ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Distorted Octahedral Coordination ◽  
Arc Melting ◽  
Distorted Octahedral ◽  
The One

The new carbides Ca4Ni3C5 and CaPd3C were prepared from the elemental components by arc melting and subsequent annealing at 700 °C. The structure of Ca4Ni3C5 was determined from single-crystal X-ray data. It crystallizes in the monoclinic space group C2/m, a = 1108.7(3) pm, b = 377.1(1) pm, c = 983.9(2) pm, β = 112.58(2)°, Z = 2. Powder data show CaPd3C to have the cubic perovskite structure with a = 414.1(2) pm. While the carbon atoms in CaPd3C are isolated from each other, they form C2 pairs in Ca4Ni3C5 with the typical triple bond C-C distance of 120(2) pm. In addition to the C2 pairs there are isolated carbon atoms in distorted octahedral coordination of four Ni atoms forming a square, which is augmented by two Ca atoms. In the one-dimensionally infinite polyanion [Ni3C5]n8n- these CNi4 squares are condensed by sharing two Ni atoms at opposite corners of the squares. A C2 pair is attached to each of the other Ni atoms in an end-on configuration. Chemical bonding within this polyanion is briefly discussed on the basis of the 18- and 8-electron rules for the Ni and C atoms, respectively. Ca4Ni3C5 is diamagnetic with a susceptibility of χ = – 12(± 5) × 10-9 m3/mol.

One-pot Synthesis of Pyrazolone Sulfones by Iodine-catalyzed Sulfenylation of Pyrazolones with Aryl Sulfonyl Hydrazides Followed by Oxidation in Water

2018 ◽  
Vol 15 (3) ◽  
pp. 380-387
Author(s):  
Xia Zhao ◽  
Xiaoyu Lu ◽  
Lipeng Zhang ◽  
Tianjiao Li ◽  
Kui Lu
Keyword(s):  
Double Bond ◽  
Efficient Method ◽  
Room Temperature ◽  
Sulfonyl Chloride ◽  
Antibacterial Activities ◽  
Oxidation Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
X Ray ◽  
Amide Form

Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of pyrazolone by aryl sulfonyl chloride failed to give pyrazolone sulfones. Thus, developing a more efficient method to synthesize pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of pyrazolone sulfone 4aa showed that the major tautomer of pyrazolone sulfones was the amide form instead of the enol form observed for pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize pyrazolone thioethers by iodine-catalyzed sulfenylation of pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.

Configuration on the C=N double bond of monosubstituted amidines and amidoximes

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Steric Effects ◽  
Model Compounds ◽  
X Ray ◽  
Analogous Model

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).

scholarly journals Synthesis and Characterization of Clay Polymer Nanocomposites of P(4VP-co-AAm) and Their Application for the Removal of Atrazine

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 721 ◽  
Author(s):  
Jorge A. Ramírez-Gómez ◽  
Javier Illescas ◽  
María del Carmen Díaz-Nava ◽  
Claudia Muro-Urista ◽  
Sonia Martínez-Gallegos ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Nanocomposite Materials ◽  
Synthesis And Characterization ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
Numerous Species ◽  
X Ray ◽  
Different Types ◽  
Synthesized Materials

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.

Quaternary Equiatomic Compounds LnZnSbO (Ln = La - Nd, Sm) with ZrCuSiAs-Type Structure

1997 ◽  
Vol 52 (12) ◽  
pp. 1467-1470 ◽  
Author(s):  
Petra Wollesen ◽  
Joachim W. Kaiser ◽  
Wolfgang Jeitschko
Keyword(s):  
Zinc Oxide ◽  
Single Crystal ◽  
Chemical Bonding ◽  
Type Structure ◽  
Variable Parameters ◽  
X Ray ◽  
Structure Factors ◽  
Cold Pressed

Abstract The five compounds LnZnSbO (Ln = La - Nd, Sm) were prepared by annealing cold-pressed pellets of the lanthanoids, zinc oxide, and antimony, or by reacting these components in a NaCl/KCl flux. They crystallize with the tetragonal ZrCuSiAs type structure, which was refined from single-crystal X-ray data of CeZnSbO : P 4/nmm, a = 419.76(4), c = 947.4(1) pm, Z = 2, R = 0.022 for 165 structure factors and 12 variable parameters. Chemical bonding in this and the formally isotypic compound CeZn1-xSb2 is briefly discussed.

scholarly journals Topology of the Electron Density and of Its Laplacian from Periodic LCAO Calculations on f-Electron Materials: The Case of Cesium Uranyl Chloride

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4227
Author(s):  
Alessandro Cossard ◽  
Silvia Casassa ◽  
Carlo Gatti ◽  
Jacques K. Desmarais ◽  
Alessandro Erba
Keyword(s):  
Electron Density ◽  
Chemical Bonding ◽  
Topological Analysis ◽  
Theoretical Description ◽  
Basis Functions ◽  
Quantum Mechanical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Orbitals ◽  
Uranyl Chloride

The chemistry of f-electrons in lanthanide and actinide materials is yet to be fully rationalized. Quantum-mechanical simulations can provide useful complementary insight to that obtained from experiments. The quantum theory of atoms in molecules and crystals (QTAIMAC), through thorough topological analysis of the electron density (often complemented by that of its Laplacian) constitutes a general and robust theoretical framework to analyze chemical bonding features from a computed wave function. Here, we present the extension of the Topond module (previously limited to work in terms of s-, p- and d-type basis functions only) of the Crystal program to f- and g-type basis functions within the linear combination of atomic orbitals (LCAO) approach. This allows for an effective QTAIMAC analysis of chemical bonding of lanthanide and actinide materials. The new implemented algorithms are applied to the analysis of the spatial distribution of the electron density and its Laplacian of the cesium uranyl chloride, Cs2UO2Cl4, crystal. Discrepancies between the present theoretical description of chemical bonding and that obtained from a previously reconstructed electron density by experimental X-ray diffraction are illustrated and discussed.

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