Electrochemical investigation of some potential antibacterials, II

1997 ◽  
Vol 75 (5) ◽  
pp. 567-574 ◽  
Author(s):  
Rajeev Jain ◽  
P. Padmaja ◽  
Seema Gupta
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Behaviour ◽  
Reduction Reaction ◽  
Carbon Electrodes ◽  
Reduction Wave ◽  
Electrochemical Investigation ◽  
Glassy Carbon Electrodes ◽  
Controlled Potential Electrolysis ◽  
Wide Range ◽  
Controlled Potential

The electrochemical behaviour of 2-(4′-sulphonamoyl)hydrazonobutyrate-1,3-diones and sulphonamoylazoaminobenzenes has been studied over a wide range of pH at dropping mercury as well as glassy carbon electrodes. Both types of compounds exhibited a 4e− reduction reaction at both electrodes. At pH > 4.5, 2-(4′-sulphonamoyl)hydrazonobutyrate-1,3-diones exhibited a 2e− reduction wave at higher potentials. Both compounds undergo a 2e− oxidation reaction. On the basis of polarography, linear and cyclic voltammetry, controlled potential electrolysis, coulometry, and spectral analysis, a detailed mechanism has been postulated for the reduction as well as the oxidation. Keywords: electrochemistry, sulphonamides, polarography, cyclic voltammetry, coulometry.

Electrochemical investigations on some potential antibacterials, I

1995 ◽  
Vol 73 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Rajeev Jain ◽  
M. Damodharan
Keyword(s):  
Cyclic Voltammetry ◽  
Glassy Carbon ◽  
Electrochemical Behaviour ◽  
Carbon Electrodes ◽  
Electron Wave ◽  
Nmr Studies ◽  
Glassy Carbon Electrodes ◽  
Single Well ◽  
Controlled Potential ◽  
Ph Range

Electrochemical behaviour of the medicinally important 4-(4′-sulphonamoyl)hydrazono-1-phenyl-3-methyl-2-pyrazolin-5-ones has been studied at d.m.e. and glassy carbon electrodes. At d.m.e., all six compounds exhibited a single, well-defined, four-electron wave in the pH range 2.5–12.0. Polarographic four-electron wave was found to be diffusion-controlled and irreversible. Similarly, cyclic voltammetry of these compounds at glassy carbon electrode exhibited a single peak. Peak potential shows shifts towards negative potential with pH, with linear segments up to pH 8.2 and are practically pH independent at higher pH values. An anodic peak at far-off positive potential was observed in the reverse scan, indicating the irreversible nature of the electrode process. Controlled potential electrolysis and coulometric studies gave the value of n as 4.0 ± 0.1 in the pH range 2.5 to 10.0. Out of the two major end products formed, one was identified as sulphanilamide and the other as 1-phenyl-3-methyl-4-amino-2-pyrazolin-5-one on the basis of IR and NMR studies. On the basis of DCP, LSV, CV, CPE, coulometry and spectral analysis, a mechanism has been postulated for the reduction of these compounds at d.m.e. and glassy carbon electrodes. Keywords: polarography, cyclic voltammetry, antibacterials, pyrazolin-5-ones.

Electrochemical behaviour and preconcentration of uranyl(VI) at Nafion-coated glassy carbon electrodes

1992 ◽  
Vol 324 (1-2) ◽  
pp. 145-159 ◽  
Author(s):  
Paolo Ugo ◽  
Barbara Ballarin ◽  
Salvatore Daniele ◽  
G.Antonio Mazzocchin
Keyword(s):  
Glassy Carbon ◽  
Electrochemical Behaviour ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes

scholarly journals Electrochemical Behaviour of N′-(p-toluenesulphonyl)-3-methyl-4-(4′-substituted arylhydrazono) pyrazolin-5-ones

2012 ◽  
Vol 9 (4) ◽  
pp. 1864-1874
Author(s):  
V. Nagaraju ◽  
R. Sreenivasulu ◽  
P. Venkata Ramana
Keyword(s):  
Electrochemical Behaviour ◽  
Reduction Process ◽  
Effect Of Solvent ◽  
Buffer Solutions ◽  
Diffusion Controlled ◽  
Controlled Potential Electrolysis ◽  
Dc Polarography ◽  
Controlled Potential ◽  
Ph Range ◽  
And Diffusion

The electrochemical behaviour of N′-(p-toluenesulphonyl)-3-methyl-4-(4′-substituted arylhydrazono) pyrazolin-5-ones has been investigated at dme and gc electrodes in buffer solutions of pH 2.0, 4.0, 6.0, 8.0 and 10.0 using dc polarography and cyclic voltammetry and coulometry. The compounds exhibit one well defined wave in the entire pH range of study. The process is irreversible and diffusion controlled. Controlled potential electrolysis indicates the involvement of four electrons in the reduction process. The effect of solvent, cations and anions, temperature and substitutents on the mechanism of reduction has been studied. Based on the results obtained the mechanism of reduction has been suggested.

Electrochemical behaviour of ABTS on aryl-modified glassy carbon electrodes

2011 ◽  
Vol 661 (2) ◽  
pp. 343-350 ◽  
Author(s):  
Elo Kibena ◽  
Uno Mäeorg ◽  
Leonard Matisen ◽  
Kaido Tammeveski
Keyword(s):  
Glassy Carbon ◽  
Electrochemical Behaviour ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes

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.

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.

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