Microwave-assisted synthesis of Cu2O microcrystals with systematic shape evolution from octahedral to cubic and their comparative photocatalytic activities

RSC Advances ◽  
2014 ◽  
Vol 4 (72) ◽  
pp. 38059-38063 ◽  
Author(s):  
Hongdan Zhang ◽  
Fuyang Liu ◽  
Benxian Li ◽  
Jiasheng Xu ◽  
Xudong Zhao ◽  
...  
Keyword(s):  
Reaction Medium ◽  
Volume Ratio ◽  
Microwave Assisted Synthesis ◽  
Shape Evolution ◽  
Microwave Assisted ◽  
Photocatalytic Activities

In this paper, it was firstly realized that the morphology of Cu2O under microwave conditions could be controlled by simply adjusting the volume ratio of the solvents in the reaction medium.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

Facile microwave-assisted synthesis and controllable architecture of three-dimensional nickel titanate

CrystEngComm ◽  
2015 ◽  
Vol 17 (24) ◽  
pp. 4562-4574 ◽  
Author(s):  
Thuy-Duong Nguyen-Phan ◽  
Chinh Nguyen Huy ◽  
Chang-Koo Kim ◽  
Eun Woo Shin
Keyword(s):  
Crystal Growth ◽  
Three Dimensional ◽  
Polyol Synthesis ◽  
Microwave Assisted Synthesis ◽  
Shape Evolution ◽  
One Pot ◽  
Microwave Assisted ◽  
Nickel Titanate

A rapid, facile, one-pot microwave-assisted polyol synthesis of novel hierarchical nickel titanate is first reported. The roles of medium dielectric and precursor counterion in the crystal growth and shape evolution are investigated.

Size and shape evolution of upconverting nanoparticles using microwave assisted synthesis

CrystEngComm ◽  
2010 ◽  
Vol 12 (7) ◽  
pp. 1993 ◽  
Author(s):  
Hai-Qiao Wang ◽  
Richard D. Tilley ◽  
Thomas Nann
Keyword(s):  
Microwave Assisted Synthesis ◽  
Shape Evolution ◽  
Size And Shape ◽  
Microwave Assisted

Microwave-assisted Efficient One-pot Synthesis of Nitriles Using Recyclable Magnetite (Fe3O4) Nanoparticles as Catalyst and Water as Solvent: A Greener Approach

2020 ◽  
Vol 10 (4) ◽  
pp. 507-517
Author(s):  
Prashant Chavan ◽  
Suhas Pednekar ◽  
Ramesh Chaughule ◽  
Anushree Lokur
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Reaction Medium ◽  
Chemical Yield ◽  
Significant Loss ◽  
Microwave Assisted Synthesis ◽  
Microwave Activation ◽  
One Pot ◽  
Microwave Assisted ◽  
Magnetite Fe3o4 ◽  
Water As Solvent

Background: There has been an increasing curiosity over the past few years to carry out organic reactions over heterogeneous nanocatalysts. Microwave activation coupled with a nanocatalyst along with water as a reaction medium makes the process further green. Microwave activation as a green process reduces reaction times, enhances product purity and improves chemical yield. Methods: Nitrile group chemistry has been explored by many researchers across the globe owing to its interesting properties and its importance in synthetic chemistry. Despite several methods being available for the synthesis of nitriles, microwave assisted synthesis of nitriles using Fe3O4 nanoparticles appears more promising. The present study is intended at developing a recyclable magnetite (Fe3O4) nanoparticles catalyzed protocol towards the synthesis of organonitrile derivatives using one pot reaction. Results: The above protocol incorporates the use of microwave for heating and water as reaction medium. Several substituted nitriles could be synthesized for excellent yields. The magnetite nanoparticles can be reused for new reaction without significant loss in activity. Conclusion: The experiment makes the protocol simple, environment friendly and economically feasible.

scholarly journals Microwave-Assisted Synthesis of Porous ZnO/SnS2Heterojunction and Its Enhanced Photoactivity for Water Purification

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
A. B. Makama ◽  
A. Salmiaton ◽  
E. B. Saion ◽  
T. S. Y. Choong ◽  
N. Abdullah
Keyword(s):  
Visible Light ◽  
Synergetic Effect ◽  
Visible Region ◽  
Microwave Assisted Synthesis ◽  
Fixed Amount ◽  
X Ray ◽  
Enhanced Absorption ◽  
Microwave Assisted ◽  
Degradation Rates ◽  
Photocatalytic Activities

Porous ZnO/SnS2nanocomposites with adjustable SnS2contents were prepared via microwave-assisted heating of different aqueous solutions of SnS2precursors in the presence of fixed amount of ZnCO3nanoparticles at pH 7. The structures, compositions, BET specific surface areas, and optical properties of the as-prepared products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, N2adsorption, and UV-Vis absorption spectra. Photocatalytic activities of the samples were tested by the removal of aqueous ciprofloxacin,CrVI, and methylene blue under visible-light (λ>420 nm) irradiation. The experimental results reveal that the as-prepared heterogeneous nanostructures exhibit much higher visible-light-driven photocatalytic activity for the degradation of the pollutants than pure SnS2nanocrystals. The photocatalytic degradation ratesCt/C0of the pollutants for the most active heterogeneous nanostructure are about 10, 49, and 9 times higher than that of pure SnS2. The enhanced photocatalytic activities exhibited by the heterojunctions could be ascribed to the synergetic effect of enhanced absorption in the visible region and the reduced rate of charge carrier recombination because of efficient separation and electron transfer from the SnS2to ZnO nanoparticles.

scholarly journals Copper Phosphotungstate-Catalyzed Microwave-Assisted Synthesis of 5-Hydroxymethylfurfural In A Biphasic System

2021 ◽  
Author(s):  
Gabriel Abranches Dias Castro ◽  
Neide Paloma Gonçalves Lopes ◽  
Sergio Antonio Fernandes ◽  
Márcio José da Silva
Keyword(s):  
Transition Metal ◽  
Reaction Medium ◽  
Water Soluble ◽  
Biphasic System ◽  
Lewis Acidity ◽  
Microwave Assisted Synthesis ◽  
Water Molecules ◽  
Microwave Assisted ◽  
Keggin Heteropolyacids ◽  
Fructose Dehydration

Abstract In this paper, we have described a novel route to produce 5-hydroxymethylfurfural (HMF), a valuable platform-molecule obtained from biomass, using transition metal-exchanged Keggin heteropolyacid salts as catalysts, in microwave-assisted reactions carried out in a water-ethyl acetate biphasic system. To avoid the use of homogenous Brønsted acid catalysts, which are corrosive and difficult to be reused, we have exchanged the protons of the Keggin heteropolyacids by transition metal cations. These salts were evaluated in the fructose dehydration, being the Cu3/2PW12O40 the most active and selective catalyst, achieving 81 % of HMF yield, after 15 min reaction at 413 K under microwave irradiation (MWI). The effects of metal cation, anion, and heteropolyanion present in the catalyst were evaluated. The greatest efficiency of Cu3/2PW12O40 was attributed to its high Lewis acidity strength, which allows that it coordinate with water molecules, consequently generating H3O+ ions in the reaction medium. Even though the catalyst has been water-soluble, it was easily reused removing the extracting phase, and adding a new load of the substrate to the remaining aqueous phase. This way, it was successfully reused without loss activity.

Microwave Assisted Synthesis of ZnO Calthrop-Like Nanostructures in Ionic-Liquid

2011 ◽  
Vol 295-297 ◽  
pp. 1397-1401 ◽  
Author(s):  
Ju Gong Zheng ◽  
Ting Yang
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Zno Nanorods ◽  
Reaction Medium ◽  
Wurtzite Structure ◽  
Microwave Assisted Synthesis ◽  
Nano Structure ◽  
Microwave Assisted ◽  
Growth Mechanics

ZnO Calthrop-like framework have been synthesized via a microwave assisted way by thermal decomposition of precursors in the ionic liquid 1-butyl-3-ethyl imidazolium tetrafluoroborate ([Beim]BF4) aqueous solution. The structure of [Beim]BF4were analyzed by means of IR and 1HNMR, The as-samples were characterized by XRD, SEM and UV techniques. The results showed that the as-prepared ZnO have wurtzite structure. nanorods have a diameter of 50 nm to100 nm and lengths of about 3 μm , and the ionic liquid [Beim]BF4can not only act as a reaction medium but also modify ZnO nanorods in the reaction. The growth mechanics of ZnO nano-structure was preliminary studied.

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