Electrochemical Oxidation of Probucol in Anhydrous Acetonitrile

1999 ◽  
Vol 64 (7) ◽  
pp. 1100-1110 ◽  
Author(s):  
Karel Nesměrák ◽  
Ivan Němec ◽  
Martin Štícha ◽  
Jiří Gabriel ◽  
Valentin Mirceski

Electrochemical oxidation of probucol in anhydrous acetonitrile was studied as a model of the metabolic oxidation of the substance. The study was performed by DC voltammetry, potentiostatic coulometry, cyclic voltammetry and preparative electrolysis. Probucol gives a single anodic wave E1/2 = 0.92 V. Cyclic voltammetry showes that its electrooxidation proceeds by formation of probucol radical. 2,6-Di-tert-butyl-4-(isopropylsulfanyl)phenol, 2,6-di-tert-butyl-4-sulfanylphenol, 2,6-di-tert-butyl-4-methylphenol and 2,6-di-tert-butylphenol were isolated as products of electrochemical oxidation.

1995 ◽  
Vol 73 (3) ◽  
pp. 362-374 ◽  
Author(s):  
Benoit Daoust ◽  
Jean Lessard

The electrochemical behavior of N,N-dimethyl-N′-phenylformamidine hydrochloride was studied on a platinum electrode. The oxidation peak at +0.90 V vs. Ag/Ag+ 0.01 M (in CH3CN −0.1 M LiClO4) was assigned to the oxidation of the chloride anion. N,N-Dimethyl-N′-(4-chlorophenyl)formamidine and N,N-dimethyl-N′-(2-chlorophenyl)formamidine were isolated from the preparative electrolysis of this amidine hydrochloride. The electrochemical behavior of N-phenylbenzamidine hydrochloride and N-phenylcyclohex-3-enecarboxamidine hydrochloride was also studied at platinum and at vitreous carbon. Cyclic voltammetry of a number of amidines was performed. Only N-arylbenzamidines showed a reduction peak at potentials less negative than −3.0 V vs. Ag/Ag+ 0.01 M (discharge potential of the medium at vitreous carbon). Preparative electrooxidations of all amidines studied were unsuccessful because of strong and rapid passivation of the anode. Keywords: amidine, electrochemical oxidation, chloride, amidine hydrochloride.


1989 ◽  
Vol 54 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Roland Meier ◽  
Gerhard Werner ◽  
Matthias Otto

Electrochemical oxidation of [V(IV)O(nta)(H2O)]- (H3nta nitrilotriacetic acid) was studied in aqueous solution by means of cyclic voltammetry, differential pulse polarography, and current sampled DC polarography on mercury as electrode material. In the pH-range under study (5.5-9.0) the corresponding V(V) complex is produced by one-electron oxidation of the parent V(IV) species. The oxidation product is stable within the time scale of cyclic voltammetry. The evaluation of the pH-dependence of the half-wave potentials leads to a pKa value for [V(IV)O(nta)(H2O)]- which is in a good agreement with previous determinations. The measured value for E1/2 is very close to the formal potential E0 calculated via the Nernst equation on the basis of known literature values for log Kox and log Kred, the complex stability constants for the oxidized and reduced form, respectively.


2010 ◽  
Vol 132 ◽  
pp. 271-278 ◽  
Author(s):  
Dan Mei Yu ◽  
Chang Guo Chen ◽  
Shu Lei ◽  
Xiao Yuan Zhou ◽  
Guo Zhong Cao

The electrochemical oxidation of sodium borohydride (NaBH4) on Pt electrode in alkaline electrolyte with the addition of thiourea has been studied by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry (CP). NaBH4 is readily to react with hydroxyl groups to release hydrogen through either direct oxidation or catalytic hydrolysis. The experimental results demonstrated that the addition of an appropriate amount of thiourea to the alkaline electrolyte resulted in the suppression of catalytic hydrolysis and diffusion of borohydride ions through the separation membrane.


2014 ◽  
Vol 937 ◽  
pp. 17-22 ◽  
Author(s):  
Sheng Tao Wang ◽  
Bao Yang Lu ◽  
Jing Kun Xu ◽  
Wei Qiang Zhou

Novel poly (selenophene-co-3-methylthiophene) was successfully achieved by directly electrochemical oxidation of the monomer mixtures of selenophene and 3-methylthiophene (3MeT) in boron trifluoride diethyl etherate. The effect of monomer concentration ratios on the copolymerization were investigated by cyclic voltammetry. The structures of as-prepared copolymers were characterized by UV-vis and infrared spectroscopy. The conductivity and thermoelectric measurements revealed the incorporation of 3MeT into the polyselenophene (PSe) chain improved significantly the conductivity and thermoelectric property of PSe.


2019 ◽  
Vol 48 (39) ◽  
pp. 14898-14913 ◽  
Author(s):  
Souvik Maity ◽  
Soumavo Ghosh ◽  
Ashutosh Ghosh

The causes behind the fluctuations from a linear dependence of the electrochemical signal of a guest bound metalloligand [CuL] with the Lewis acidity of redox-inactive cations were established by using UV-vis spectroscopy and cyclic voltammetry.


2011 ◽  
Vol 396-398 ◽  
pp. 1730-1735 ◽  
Author(s):  
Yan Xu ◽  
Yue Hua Wen ◽  
Jie Cheng ◽  
Gao Ping Cao ◽  
Yu Sheng Yang

Electrochemical oxidation of tiron in the presence of H2O as a nucleophile in strongly acidic aqueous solutions was studied by cyclic voltammetry, controlled-voltage coulometry and spectrometric investigations. The mechanism of electrochemical reaction is confirmed by spectrophotometric tracing in various times of controlled-voltage coulometry. The voltammetric and spectrophotometric foundations indicate that a 1,4-Michael addition of H2O from its hydroxy moiety to the position 4 of electrochemically derived o-quinone is occurred. The electrochemical oxidation and reduction of tiron has been successfully accomplished by controlled-voltage coulometry in a redox flow-through type cell and the final electro-reduced product was characterized by spectrophotometric, 1H NMR and mass spectrometric methods. It is demonstrated that the electro-oxidation of tiron follows an ECE mechanism in acidic aqueous solutions, leading to formation of a new compound of para- benzoquinone derivative.


2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Thiery Auguste Foffié Appia ◽  
Lassiné Ouattara

<p>The electrooxidation of amoxicillin (AMX) on the iridium oxide electrode thermally prepared (400°C) has been investigated by cyclic voltammetry and preparative electrolysis. Physical characterization by Scanning Electron Microscopy (SEM) showed that the IrO<sub>2</sub> electrode has a rough surface with pores' presence. In cyclic voltammetry, the oxidation of AMX occurs directly at the anode's surface or via the higher degree oxide of iridium oxide (IrO<sub>3</sub>).  It is noted that the oxidation process of AMX can be controlled by diffusion combined with the phenomenon of adsorption. In preparative electrolysis, the effect of several parameters has been investigated. These are the current density, the support medium, the initial pH. The findings obtained show a weak degradation of amoxicillin. The Chemical Oxygen Demand (COD) reduction rate is less than 11% under our experimental conditions, indicating that the IrO2 electrode leads to the parent compound's conversion. Also, the degradation of the organic compound is favored in a very acidic medium.<strong></strong></p><p>Furthermore, the effect of inorganic ions such as SO<sub>4</sub><sup>2-</sup>, PO<sub>4</sub><sup>3-</sup>, NO<sub>3</sub><sup>-</sup>, Cl<sup>-</sup> was evaluated. Investigations show that these ions' effects are diverse, with COD reduction rates ranging from 2.47%; 2.68%; 7.7%; 16.41%, and 71.65%, respectively, in the absence and the presence of SO<sub>4</sub><sup>2-</sup>, PO<sub>4</sub><sup>3-</sup>, NO<sub>3</sub><sup>-</sup>, Cl<sup>- </sup>ions. SO<sub>4</sub><sup>2-</sup> have virtually no effect on enhancing the degradation of amoxicillin. PO<sub>4</sub><sup>3-</sup> ions provide a slight improvement in amoxicillin degradation. As for nitrate ions, their influence is 2.31 times that of phosphate ions. Chloride ions improve the performance of the electrooxidation of amoxicillin on IrO2 very significantly. The presence of chloride ions makes it possible to go from 2928.35 (absence of inorganic ions) to 33.19 kWh per Kg of COD. This represents an energy gain of over 98%.</p>


1989 ◽  
Vol 3 (4) ◽  
pp. 275-297 ◽  
Author(s):  
Nikola Batina ◽  
Scott A. Chaffins ◽  
Bruce E. Kahn ◽  
Frank Lu ◽  
James W. McCargar ◽  
...  

Author(s):  
Magomed A. Akhmedov ◽  
Shagabudin Sh. Khidirov ◽  
Madina Yu. Kaparova

In this paper the electrochemical oxidation of dimethyl sulfone (DMSO2) on a platinum electrode in an alkaline medium has been studied by cyclic voltammetry. It is shown that during the electrochemical oxidation of dimethylsulfone in an alkaline medium on a smooth platinum electrode, a significant suppression of the oxygen evolution (O2) occurs in the potential range of E = 1.3-2.0 V. By scanning electron microscopy methods, Raman scattering and infrared spectrometry it is shown that the main substance is the dimethyl disulfone (DMDSO2) during the anodic oxidation of DMSO2 on a platinum electrode. By the preparative electrolysis of aqueous solutions of various concentrations of DMSO2 in 0.1 M NaOH solution at controlled potentials E = 1.6 and 1.8 V it is established that the current yield of the base material is not more than 84%. Based on the data of the physicochemical analysis of the final products of preparative electrolysis, a mechanism is proposed for the formation of dimethyl disulfone in an alkaline medium. It has been shown that the oxidation of dimethyl sulfone proceeds in the oxygen region by breaking C-S bonds in the DMSO2 molecule to form methyl (CH3•) and methylsulfonic (CH3S•(O)2) radicals. It is assumed that the methylsulfone radicals readily dimerize with the formation of stable DMDSO2 molecules and are desorbed in the bulk of the solution, and the methyl radicals bind to the HO radicals to form methanol molecules. The latter is well chemisorbed on the surface of platinum with the formation of adsorbed COH particles that are oxidized on a platinum electrode with the formation and evolution of carbon dioxide (CO2) from the volume of the anolyte solution. The formation of molecules of methanol was identified by the method of chromato-mass -spectrometry, and the emission of carbon dioxide by the gravimetry.


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