Electrochemical behavior of C-methoxy, amino, cyano, and mercapto nitrones

1992 ◽  
Vol 70 (7) ◽  
pp. 2076-2080 ◽  
Author(s):  
Bruce J. Acken ◽  
David E. Gallis ◽  
James A. Warshaw ◽  
DeLanson R. Crist
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Behavior ◽  
Spin Trapping ◽  
Redox Behavior ◽  
Electron Process ◽  
Controlled Potential Electrolysis ◽  
Controlled Potential

The redox behavior of various C-substituted nitrones was investigated by cyclic voltammetry in acetonitrile. These included C-methoxynitrones (MeO)CR = N(O)t-Bu with R = C6H5(1a), p-MeOC6H4 (1b), p-NO2C6H4 (1c), and H (1d) and nitrones YCH = N(O)t-Bu with Y = n-BuS (2a), CN (2b), and C6H5NH (2c). All gave anodic peaks which can be identified as oxidations of the nitrone function. Controlled potential electrolysis of 1a at 1.05 V (SCE) showed that its oxidation was a one-electron process. Reduction of 1a occurs stepwise at −2.08 and at −2.47 V, the same potential for reduction of methyl N-tert-butylbenzimidate (MeO)CPh = Nt-Bu. With electrochemical windows of ca. 3 V, all of the nitrones studied appear suitable for spin-trapping experiments.

scholarly journals An Investigation on the Electrochemical Behavior and Antibacterial and Cytotoxic Activity of Nickel Trithiocyanurate Complexes

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1782
Author(s):  
Amir M. Ashrafi ◽  
Pavel Kopel ◽  
Lukas Richtera
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Cyclic Voltammetry ◽  
Antibacterial Activity ◽  
Cytotoxic Activity ◽  
Cell Lines ◽  
Electrochemical Behavior ◽  
Antibacterial Properties ◽  
Redox Behavior ◽  
Electrochemical Redox

The electrochemical redox behavior of three trinuclear Ni(II) complexes [Ni3(abb)3(H2O)3(µ-ttc)](ClO4)3 (1), [Ni3(tebb)3(H2O)3(µ-ttc)](ClO4)3·H2O (2), and [Ni3(pmdien)3(µ-ttc)](ClO4)3 (3), where abb = 1-(1H-benzimidazol-2-yl)-N-(1H-benzimidazol-2-ylmethyl)methan-amine, ttcH3 = trithiocyanuric acid, tebb = 2-[2-[2-(1H-benzimidazol-2-yl)ethylsulfanyl]ethyl]-1H-benzimidazole, and pmdien = N,N,N′,N″,N″-pentamethyldiethylenetriamine is reported. Cyclic voltammetry (CV) was applied for the study of the electrochemical behavior of these compounds. The results confirmed the presence of ttc and nickel in oxidation state +2 in the synthesized complexes. Moreover, the antibacterial properties and cytotoxic activity of complex 3 was investigated. All the complexes show antibacterial activity against Staphylococcus aureus and Escherichia coli to different extents. The cytotoxic activity of complex 3 and ttcNa3 were studied on G-361, HOS, K-562, and MCF7 cancer cell lines. It was found out that complex 3 possesses the cytotoxic activity against the tested cell lines, whereas ttcNa3 did not show any cytotoxic activity.

Clam-shaped cyclam-functionalized porphyrin for electrochemical reduction of carbon dioxide

2019 ◽  
Vol 23 (04n05) ◽  
pp. 453-461
Author(s):  
Sumana Tawil ◽  
Hathaichanok Seelajaroen ◽  
Amorn Petsom ◽  
Niyazi Serdar Sariciftci ◽  
Patchanita Thamyongkit
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Cyclic Voltammetry ◽  
Catalytic Activity ◽  
Electrochemical Reduction ◽  
Target Compound ◽  
Faradaic Efficiency ◽  
Controlled Potential Electrolysis ◽  
Improved Stability ◽  
Controlled Potential

A clam-shaped molecule comprising a Zn(II)-porphyrin and a Zn(II)-cyclam is synthesized and characterized. Its electrochemical behavior and catalytic activity for homogeneous electrochemical reduction of carbon dioxide (CO[Formula: see text] are investigated by cyclic voltammetry and compared with those of Zn(II)-meso-tetraphenylporphyrin and Zn(II)-cyclam. Under N2-saturated conditions, cyclic voltammetry of the featured complex has characteristics of its two constituents, but under CO2-saturated conditions, the target compound exhibits significant current enhancement. Iterative reduction under electrochemical conditions indicated the target compound has improved stability relative to Zn(II)-cyclam. Controlled potential electrolysis demonstrates that, without addition of water, methane (CH[Formula: see text] is the only detectable product with 1% Faradaic efficiency (FE). The formation of CH4 is not observed under the catalysis of the Zn(II)-porphyrin benchmark compound, indicating that the CO2-capturing function of the Zn(II)-cyclam unit contributes to the catalysis. Upon addition of 3% v/v water, the electrochemical reduction of CO2 in the presence of the target compound gives carbon monoxide (CO) with 28% FE. Dominance of CO formation under these conditions suggests enhancement of proton-coupled reduction. Integrated action of these Zn(II)-porphyrin and Zn(II)-cyclam units offers a notable example of a molecular catalytic system where the cyclam ring captures and brings CO2 into the proximity of the porphyrin catalysis center.

Reductive dechlorination of DDT electrocatalyzed by synthetic cobalt porphyrins in N,N′-dimethylformamide

2011 ◽  
Vol 15 (01) ◽  
pp. 66-74 ◽  
Author(s):  
Weihua Zhu ◽  
Yuanyuan Fang ◽  
Wei Shen ◽  
Guifen Lu ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Reaction Time ◽  
Oxidation State ◽  
Reductive Dechlorination ◽  
Reaction Products ◽  
Ms Analysis ◽  
Controlled Potential Electrolysis ◽  
Cobalt Porphyrins ◽  
Controlled Potential ◽  
Uv Visible

Two cobalt porphyrins, (OEP) CoII and (TPP) CoII , where OEP and TPP are the dianions of octaethylporphyrin and tetraphenylporphyrin, respectively, were examined as electrocatalysts for the reductive dechlorination of DDT (1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane) in N,N′-dimethylformamide (DMF) containing 0.1 M tetra-n-butylammonium perchlorate (TBAP). No reaction is observed between DDT and the porphyrin in its Co(II) oxidation state but this is not the case for the reduced Co(I) forms of the porphyrins which electrocatalyze the dechlorination of DDT, giving initially DDD (1,1-bis(4-chlorophenyl)-2,2-dichloroethane), DDE (1,1-bis(4-chlorophenyl)-2, 2-dichloroethylene) and DDMU (1,1-bis(4-chlorophenyl)-2-chloroethylene) as determined by GC-MS analysis of the reaction products. A further dechlorination product, DDOH (2,2-bis(4-chlorophenyl)ethanol), is also formed on longer timescales when using (TPP)Co as the electroreduction catalyst. The effect of porphyrin structure and reaction time on the dechlorination products was examined by GC-MS, cyclic voltammetry, controlled potential electrolysis and UV-visible spectroelectrochemistry and a mechanism for the reductive dechlorination is proposed.

scholarly journals Integrated Study of the Dinitrobenzene Electroreduction Mechanism by Electroanalytical and Computational Methods

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Andrey S. Mendkovich ◽  
Mikhail A. Syroeshkin ◽  
Ludmila V. Mikhalchenko ◽  
Mikhail N. Mikhailov ◽  
Alexander I. Rusakov ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Quantum Chemical ◽  
Bond Cleavage ◽  
Digital Simulation ◽  
Radical Anions ◽  
Theoretical Methods ◽  
Controlled Potential Electrolysis ◽  
Proton Donors ◽  
Controlled Potential ◽  
Integrated Study

Electroreduction of 1,2-, 1,3-, and 1,4-dinitrobenzenes in DMF has been investigated by a set of experimental (cyclic voltammetry, chronoamperometry, and controlled potential electrolysis) and theoretical methods (digital simulation and quantum chemical calculations). The transformation of only one nitro group is observed in the presence of proton donors. The process selectivity is provided by reactions of radical anions' intermediate products. The key reactions here are protonation of radical anions of nitrosonitrobenzenes and N-O bond cleavage in radical anions of N-(nitrophenyl)-hydroxylamines.

On the One and Two-Electron Oxidations of Water-Soluble Zinc Porphyrins in Aqueous Media

1981 ◽  
Vol 36 (5) ◽  
pp. 596-600 ◽  
Author(s):  
Michael Neumann-Spallart ◽  
K. Kalyanasundaram
Keyword(s):  
Cyclic Voltammetry ◽  
Aqueous Media ◽  
Water Soluble ◽  
Chemical Methods ◽  
Controlled Potential Electrolysis ◽  
Half Wave ◽  
Controlled Potential ◽  
Zinc Porphyrins ◽  
The One ◽  
Soluble Zinc

The one and two-electron oxidations of water soluble ionic zinc porphyrins (Zinctetra-methylpyridylporphyrin, ZnTMPyP, Zinc-tetra-p-sulfonato-phenyl-porphyrin, ZnTPPS, and Zinc-tetra-p-carboxy-phenylporphyrin, ZnTPPC) leading to the porphyrin Π-cations and Π-dications have been investigated in water by electrochemical (cyclic voltammetry and controlled potential electrolysis) and chemical methods. The half-wave potentials for the oxidation are shown to be markedly dependent on the charge on the β-substituents. While the one-electron oxidations for all these porphyrins are reversible, the dication formation leads to labile isoporphyrins as intermediates

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