scholarly journals SYNTHESIS, CHARACTERIZATION AND CYCLAZATION OF PYRAN USING Ag2O NANOPARTICLE FROM NATURAL SOURCE “GINGER”

2021 ◽  
Vol 52 (5) ◽  
pp. 1171-1184
Author(s):  
Ruaa M. D.
Keyword(s):  
Heterocyclic Compounds ◽  
Coupling Reaction ◽  
Chemical Separation ◽  
Zingiber Officinale ◽  
Chemical Characteristics ◽  
High Productivity ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Ag2o Nanoparticles ◽  
Hetero Compounds

This study was aimed to synthesis Ag2O nanoparticles (N.P.s) utilizing the Ginger plant (Zingiber officinale) extract. As catalysts for pyran derivatives formation employing a three-component coupling reaction among aromatic and aliphatic aldehydes, malononitrile, and dimedone. The nanoparticles exhibit robust catalytic activity with high productivity. Results revealed that Ag2O NPs improved various vital features, like higher yields, reaction time, simple chemical separation, catalytic economic efficiency, and quick process. This study aimed to cyclize heterocyclic compounds to provide new hetero compounds applying nano-oxides obtained from natural (unmanufactured) sources and used in several medical, pharmaceutical, and industrial implementations. The outcomes nanoparticles were examined by Fourier Transform Infrared spectroscopy (FTIR) and transmission electron microscopy (T.E.M.); the chemical characteristics of the outcome compounds were tested by spectroscopy techniques (FTIR spectroscopy and 1H-NMR).

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

Synthesis and Study the Properties of a Solar Cell of Gold Nanoparticles Prepared in a Simple Chemical Way

2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
X Ray ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Scanning Electron

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.

Solvothermal synthesis of hollow Eu2O3 microspheres using carbon template-assisted method

2012 ◽  
Vol 66 (8) ◽  
Author(s):  
Li-Xin Zhang ◽  
Yi-Xin Sun ◽  
Hong-Fang Jiu ◽  
Yue-Hua Fu ◽  
Yuan-Zhong Wang ◽  
...  
Keyword(s):  
Solvothermal Synthesis ◽  
Sol Gel ◽  
Hollow Structure ◽  
Inorganic Materials ◽  
Carbon Sphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Productivity ◽  
Carbon Template ◽  
Transmission Electron

AbstractThis work presents a sol-gel carbon sphere template-assisted method of hollow Eu2O3 microspheres preparation. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), as well as photoluminescence (PL) were used to characterise the products. The formation of hollow structure Eu2O3 microspheres can be assigned to a sol-gel carbon template. Furthermore, this work may confirm that the precursor sol-gel can be loaded onto the inner as well as the outer surface of carbon templates similarly as ions and nanocrystals. The presented method can afford a simple and efficient technique to obtain a series of hollow structure inorganic materials with high productivity.

scholarly journals Preparation and Characterization of Self-Assembled Nanoparticles of Hyaluronic Acid-Deoxycholic Acid Conjugates

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Xuemeng Dong ◽  
Chenguang Liu
Keyword(s):  
Hyaluronic Acid ◽  
Deoxycholic Acid ◽  
Structural Characteristics ◽  
Cetylpyridinium Chloride ◽  
Coupling Reaction ◽  
Critical Aggregation Concentration ◽  
Transmission Electron ◽  
Fluorescence Quenching Method ◽  
Self Assembled ◽  
Quenching Method

Novel amphiphilic biopolymers were synthesized using hyaluronic acid (HA) as a hydrophilic segment and deoxycholic acid (DOCA) as a hydrophobic segment by a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide mediated coupling reaction. The structural characteristics of the HA-DOCA conjugates were investigated usingH1NMR. Self-assembled nanoparticles were prepared based on HA-DOCA conjugates, and its characteristics were investigated using dynamic laser light scattering, transmission electron microscopy (TEM), and fluorescence spectroscopy. The mean diameter was about 293.5 nm with unimodal size distribution in distilled water. The TEM images revealed that the shape of HA-DOCA self-aggregates was spherical. The critical aggregation concentration (CAC) was in the range of 0.025–0.056 mg/mL. The partition equilibrium constant (Kv) of pyrene in self-aggregates solution was from1.45×104to3.64×104. The aggregation number of DOCA groups per hydrophobic microdomain, estimated by the fluorescence quenching method using cetylpyridinium chloride, increased with increasing degree of substitution.

Second Phases and Impurity Segregations in MgO- and NiO-CO-Doped Alumina

1993 ◽  
Vol 319 ◽  
Author(s):  
K. Park ◽  
C. Sung ◽  
T. Vasilos
Keyword(s):  
Electron Microscopy ◽  
Stacking Faults ◽  
Chemical Characteristics ◽  
Analytical Transmission Electron Microscopy ◽  
Triple Junctions ◽  
Sintering Process ◽  
Fine Grained ◽  
Transmission Electron ◽  
Second Phases ◽  
Co Doped

AbstractThe microstructural and chemical characteristics of the segregated particles, Ni-(Mg)-Al spinel phases, and K-ß’’’ alumina precipitates in fine-grained alumina co-doped with 0.15 wt % of MgO and 0.10 wt % of NiO were studied using analytical transmission electron microscopy. The segregated Ni particles and second phases were generally found at triple junctions or on grain boundaries. The K-ß’’’ alumina precipitates were found to contain occasionally a high density of stacking faults. These microstructural observations point out the location of the dopants and impurities during the sintering process.

scholarly journals Carboxylated Chitosan Nanocrystals: Novel Synthetic Route and Application as Superior Support for Gold-Catalyzed Reactions

2020 ◽  
Author(s):  
Tony Jin ◽  
Davis Kurdyla ◽  
Sabahudin Hrapovic ◽  
Alfred Leung ◽  
Sophie Régnier ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Coupling Reaction ◽  
Primary Alcohols ◽  
X Ray Diffraction ◽  
Catalytic Activities ◽  
Glycosidic Bonds ◽  
Carboxylate Groups ◽  
Transmission Electron ◽  
Nitrophenol Reduction ◽  
Catalyzed Reactions

<p>Chitin nanocrystals (ChNCs) were prepared by partial cleavage of glycosidic bonds in chitin with concurrent oxidation of chitin C6 primary alcohols to produce carboxylate groups on the surface of the ChNCs. Following alkaline deacetylation of the ChNCs in the presence of NaBH<sub>4</sub> to inhibit “end-peeling” afforded chitosan nanocrystals (ChsNCs) with a degree of deacetylation (DDA) >80%. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform Infrared (FTIR) spectroscopy were used to determine the morphology and composition of these carboxylated ChNCs and ChsNCs. Subsequently, two methods were used to deposit Au onto the nanocrystals, and the catalytic activities of the resulting biomass-based nanocatalysts were tested for the 4-nitrophenol reduction and the aldehyde-amine-alkyne (A<sup>3</sup>) coupling reaction. In particular, Au nanoparticles over ChsNCs featured the highest turnover frequency value for the 4-nitrophenol reduction reported to date. Spectroscopic and imaging techniques confirmed the importance of controlling precisely the redox state of Au as it is being deposited to afford highly disperse active site on the bio-nano-support. </p>

scholarly journals Recent Advances in the Applications of the Intramolecular Suzuki Cross-coupling Reaction in Cyclization and Heterocyclization: An Update

2020 ◽  
Vol 23 (22) ◽  
pp. 2469-2488 ◽  
Author(s):  
Majid M. Heravi ◽  
Masoumeh Malmir ◽  
Razieh Moradi
Keyword(s):  
Organic Chemistry ◽  
Boronic Acid ◽  
Heterocyclic Compounds ◽  
Aryl Halide ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Synthetic Organic Chemistry ◽  
Previous Review ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed

: The palladium-catalyzed reaction of aryl halide and boronic acid for the formation of C–C bonds so-called Suzuki–Miyaura cross-coupling reaction has many applications in Modern Synthetic Organic Chemistry. In 2013, we emphasized the applications of the intramolecular Suzuki cross-coupling reaction in cyclization and heterocyclization. Due to a plethora relevant papers appeared in the chemical literature, herein, we wish to cover by updating our previous review, the applications of the intramolecular Suzuki cross-coupling reaction in cyclization and heterocyclization leading to various homocyclic and heterocyclic compounds reported during a period of 2013 to 2018.

Highly Efficient and Recyclable Diatomite-Supported Pd Nanoparticles for the Suzuki-Miyaura Coupling Reaction

2010 ◽  
Vol 113-116 ◽  
pp. 1824-1827 ◽  
Author(s):  
Cheng Jun Hao ◽  
Xiao Jun Zhao
Keyword(s):  
Palladium Nanoparticles ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Xrd Analysis ◽  
Reaction Rates ◽  
X Ray ◽  
Highly Active ◽  
Transmission Electron ◽  
High Yields ◽  
Supported Pd

The Suzuki-Miyaura coupling reaction catalyzed by Pd nanoparticles immobilized on widespread natural diatomite has been reported in this report. The reaction showed enhanced reaction rates, high yields, and the conditions were environmentally friendly. The highly active heterogeneous catalyst of palladium nanoparticles allow the reaction to be performed at low catalyst levels, and could be reused 5 times with little loss of activity. Transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analysis characteried the diatomite-supported Pd(0) nanoparticles as catalyst for the reaction.

scholarly journals Characterizing black carbon in rain and ice cores using coupled tangential flow filtration and transmission electron microscopy

2015 ◽  
Vol 8 (9) ◽  
pp. 3959-3969 ◽  
Author(s):  
A. Ellis ◽  
R. Edwards ◽  
M. Saunders ◽  
R. K. Chakrabarty ◽  
R. Subramanian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Black Carbon ◽  
Ice Core ◽  
Ice Cores ◽  
Chemical Characteristics ◽  
Transmission Electron ◽  
Melt Water ◽  
Flow Filtration ◽  
Physical And Chemical

Abstract. Antarctic ice cores have been used to study the history of black carbon (BC), but little is known with regards to the physical and chemical characteristics of these particles in the remote atmosphere. Characterization remains limited by ultra-trace concentrations in ice core samples and the lack of adequate methods to isolate the particles unaltered from the melt water. To investigate the physical and chemical characteristics of these particles, we have developed a tangential flow filtration (TFF) method combined with transmission electron microscopy (TEM). Tests using ultrapure water and polystyrene latex particle standards resulted in excellent blanks and significant particle recovery. This approach has been applied to melt water from Antarctic ice cores as well as tropical rain from Darwin, Australia with successful results: TEM analysis revealed a variety of BC particle morphologies, insoluble coatings, and the attachment of BC to mineral dust particles. The TFF-based concentration of these particles has proven to give excellent results for TEM studies of BC particles in Antarctic ice cores and can be used for future studies of insoluble aerosols in rainwater and ice core samples.

Sign in / Sign up

Export Citation Format

Share Document