Electrochemistry synthesis of 1,2,4,5-tetrasubstituted imidazoles from enamines and benzylamines

2021 ◽  
Author(s):  
Wenxing Wang ◽  
Shuo Zhang ◽  
Guang Shi ◽  
Zhiwei Chen
Keyword(s):  
Electrochemical Method ◽  
Tetrasubstituted Imidazoles

An electrochemical method for the synthesis of 1,2,4,5-tetrasubstituted imidazoles is developed under undivided electrolytic conditions, which have been realized based on electrochemical C(sp3)–H Amination via enamines and amine. It uses...

MEASUREMENT OF THE DIFFUSIVITY OF OXYGEN IN HIGH--TEMPERATURE LIQUID SILVER BY ELECTROCHEMICAL METHOD

2010 ◽  
Vol 46 (3) ◽  
pp. 277-281 ◽  
Author(s):  
Yunming GAO ◽  
Jianxin SONG ◽  
Yeqin ZHANG ◽  
Xingmin GUO
Keyword(s):  
High Temperature ◽  
Electrochemical Method ◽  
Liquid Silver ◽  
Temperature Liquid

Synthesis of some Novel Imidazoles Catalyzed by Co3O4 Nanoparticles and Evaluation of their Antibacterial Activities

2018 ◽  
Vol 21 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Mohammad A. Ghasemzadeh ◽  
Mohammad H. Abdollahi-Basir ◽  
Zahra Elyasi
Keyword(s):  
Cobalt Oxide ◽  
Ammonium Acetate ◽  
Reaction Times ◽  
Antibacterial Activities ◽  
Primary Amines ◽  
Oxide Nanoparticles ◽  
Co3o4 Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Ft Ir ◽  
Tetrasubstituted Imidazoles

Aim and Objective: The multi-component condensation of benzil, primary amines, ammonium acetate and various aldehydes was efficiently catalyzed using cobalt oxide nanoparticles under ultrasonic irradiation. This approach describes an effective and facile method for the synthesis of some novel 1,2,4,5-tetrasubstituted imidazole derivatives with several advantages such as high yields and short reaction times and reusability of the catalyst. Moreover, the prepared heterocyclic compounds showed high antibacterial activity against some pathogenic strains. Materials and Method: The facile and efficient approaches for the preparation of Co3O4 nanoparticles were carried out by one step method. The synthesized heterogeneous nanocatalyst was characterized by spectroscopic analysis including EDX, FE-SEM, VSM, XRD and FT-IR analysis. The as-synthesized cobalt oxide nanoparticles showed paramagnetic behaviour in magnetic field. In addition, the catalytic influence of the nanocatalyst was examined in the one-pot reaction of primary amines, benzil, ammonium acetate and diverse aromatic aldehydes under ultrasonic irradiation. All of the 1,2,4,5-tetrasubstituted imidazoles were investigated and checked with m.p., 1H NMR, 13C NMR and FT-IR spectroscopy techniques. The antibacterial properties of the heterocycles were evaluated in vitro by the disk diffusion against pathogenic strains such as Escherichia coli (EC), Bacillus subtillis (BS), Staphylococcus aureus (SA), Salmonellatyphi (ST) and Shigella dysentrae (SD) species. Results: In this research cobalt oxide nanostructure was used as a robust and green catalyst in the some novel imidazoles. The average particle size measured from the FE-SEM image is found to be 20-30 nm which confirmed to the obtained results from XRD pattern. Various electron-donating and electron-withdrawing aryl aldehydes were efficiently reacted in the presence of Co3O4 nanoparticles. The role of the catalyst as a Lewis acid is promoting the reactions with the increase in the electrophilicity of the carbonyl and double band groups. To investigate the reusability of the catalyst, the model study was repeated using recovered cobalt oxide nanoparticles. The results showed that the nanocatalyst could be reused for five times with a minimal loss of its activity. Conclusion: We have developed an efficient and environmentally friendly method for the synthesis of some tetrasubstituted imidazoles via three-component reaction of benzil, primary amines, ammonium acetate and various aldehydes using Co3O4 NPs. The present approach suggests different benefits such as: excellent yields, short reaction times, simple workup procedure and recyclability of the magnetic nanocatalyst. The prepared 1,2,4,5-tetrasubstituted imidazoles revealed high antibacterial activities and can be useful in many biomedical applications.

Detecting Critical Crevice Temperature for Duplex Stainless Steels in Chloride Solutions

CORROSION ◽  
2011 ◽  
Vol 67 (2) ◽  
pp. 025004-1-025004-7 ◽  
Author(s):  
D. Han ◽  
Y. Jiang ◽  
B. Deng ◽  
L. Zhang ◽  
J. Gao ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Crevice Corrosion ◽  
Electrochemical Method ◽  
Duplex Stainless Steels ◽  
Good Reproducibility ◽  
X Ray ◽  
Initiation Step ◽  
Critical Pitting Temperature ◽  
Preferential Dissolution ◽  
Scanning Electron

Abstract A simple and rapid electrochemical method for the evaluation of crevice corrosion in duplex stainless steels (DSS) is described. Three types of DSS—namely, UNS S32101, UNS S31803, and UNS S32750—were tested in 1 mol/L sodium chloride (NaCl) solutions. Results showed good reproducibility with a typical standard deviation of below 3°C. The critical pitting temperature (CPT) for the same specimens was also investigated in 1 mol/L NaCl solutions. An approximately 20°C decrease from CPT to critical crevice temperature (CCT) was observed and subsequently explained. Then, the morphologies of crevice corrosion were studied using scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDS) method. The SEM/EDS study revealed that the ferrite phase was the site where preferential dissolution took place at the initiation step of crevice corrosion, which was in accordance with the prediction by calculating the critical crevice index. Moreover, repassivation was detected with the development of crevice corrosion. The reason was clarified by combining the results obtained with a successful diffusion model, and eventually the crevice corrosion progress was illustrated schematically.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Electrochemical bubble generation via hydrazine oxidation for the in situ control of an electrodeposited conducting polymer micro/-nanostructure

RSC Advances ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 11020-11025
Author(s):  
David Possetto ◽  
Luciana Fernández ◽  
Gabriela Marzari ◽  
Fernando Fungo
Keyword(s):  
Conducting Polymer ◽  
Electrochemical Method ◽  
Bubble Generation ◽  
Hydrazine Oxidation ◽  
In Situ Control

An electrochemical method to manipulate the size and density of electrodeposited polypyrrole structures at the micro-nanoscale by the discharge of hydrazine.

scholarly journals Ultralong π-Conjugated Bis(terpyridine)metal Polymer Wires Covalently Bound to a Carbon Electrode: Fast Redox Conduction and Redox Diode Characteristics

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4267
Author(s):  
Kuo-Hui Wu ◽  
Ryota Sakamoto ◽  
Hiroaki Maeda ◽  
Eunice Jia Han Phua ◽  
Hiroshi Nishihara
Keyword(s):  
Metal Complex ◽  
Electrochemical Method ◽  
Redox Reactions ◽  
Cyclic Voltammograms ◽  
Wire Arrays ◽  
Reversible Redox ◽  
Complex Linear ◽  
Complex Polymer ◽  
Metal Polymer ◽  
Hclo4 Solution

We developed an efficient and convenient electrochemical method to synthesize π-conjugated redox metal-complex linear polymer wires composed of azobenzene-bridged bis(terpyridine)metal (2-M, M = Fe, Ru) units covalently immobilized on glassy carbon (GC). Polymerization proceeds by electrochemical oxidation of bis(4′-(4-anilino)-2,2′:6′,2″-terpyridine)metal (1-M) in a water–acetonitrile–HClO4 solution, affording ultralong wires up to 7400 mers (corresponding to ca. 15 μm). Both 2-Fe and 2-Ru undergo reversible redox reactions, and their redox behaviors indicate remarkably fast redox conduction. Anisotropic hetero-metal-complex polymer wires with Fe and Ru centers are constructed via stepwise electropolymerization. The cyclic voltammograms of two hetero-metal-complex polymer wires, GC/[2-Fe]–[2-Ru] (3) and GC/[2-Ru]–[2-Fe] (4), show irreversible redox reactions with opposite electron transfer characteristics, indicating redox diodelike behavior. In short, the present electrochemical method is useful to synthesize polymer wire arrays and to integrate functional molecules on carbon.

scholarly journals In situ evolution of surface Co2CrO4 to CoOOH/CrOOH by electrochemical method: Toward boosting electrocatalytic water oxidation

2021 ◽  
Vol 42 (7) ◽  
pp. 1096-1101 ◽  
Author(s):  
Jinxiu Zhao ◽  
Xiang Ren ◽  
Xu Sun ◽  
Yong Zhang ◽  
Qin Wei ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Electrochemical Method
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