Cyclic voltammetry of solid diphenylamine crystals immobilized on an electrode surface and in the presence of an aqueous solution

2001 ◽  
Vol 6 (4) ◽  
pp. 265-271 ◽  
Author(s):  
György Inzelt
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Electrode Surface

scholarly journals Effective Enantiodiscrimination in Electroanalysis Based on a New Inherently Chiral 1,1′-Binaphthyl Selector Directly Synthesizable in Enantiopure Form

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2175
Author(s):  
Giorgia Bonetti ◽  
Serena Arnaboldi ◽  
Sara Grecchi ◽  
Giulio Appoloni ◽  
Elisabetta Massolo ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrode Surface ◽  
Potential Difference ◽  
Synthetic Route ◽  
Hplc Separation ◽  
Chiral Selectors ◽  
Electrode Surfaces ◽  
Inherently Chiral

Enantioselective electroanalysis, which aims to discriminate the enantiomers of electroactive chiral probes in terms of potential difference, is a very attractive goal. To achieve this, its implementation is being studied for various "inherently chiral" selectors, either at the electrode surface or in the medium, yielding outstanding performance. In this context, the new inherently chiral monomer Naph2T4 is introduced, based on a biaromatic atropisomeric core, which is advantageously obtainable in enantiopure form without HPLC separation steps by a synthetic route hinging on enantiopure 2,2’-dibromo-1,1’-binaphthalenes. The antipodes of the new inherently chiral monomer can be easily electrooligomerized, yielding inherently chiral electrode surfaces that perform well in both cyclic voltammetry (CV) enantiodiscrimination tests with pharmaceutically interesting molecules and in magnetoelectrochemistry experiments.

Redox Properties of Iron Complexes with Pentadentate Bispidine Ligands

2014 ◽  
Vol 67 (3) ◽  
pp. 398 ◽  
Author(s):  
Peter Comba ◽  
Hubert Wadepohl ◽  
Arkadius Waleska
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Coordination Chemistry ◽  
Aqueous Solutions ◽  
Iron Complexes ◽  
Redox Properties

The solution coordination chemistry of iron complexes with the pentadentate bispidine ligands L1, L2, and L3 (dimethyl 9-oxo-2,4-di(pyridin-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1,5-dicarboxylate derivatives) was examined. While in acetonitrile, (L1,2)FeII/III species have a preference for Cl– as co-ligand. The corresponding aqua and hydroxido complexes also prevail in the presence of Cl– in aqueous solution. The observed FeII/III potentials in water (cyclic voltammetry) and potentials of (L1–3)FeIV=O (buffered and unbuffered aqueous solutions) are strikingly similar, i.e. the latter are assigned to (L1–3)FeII/III potentials, and published potentials of FeIV=O complexes with other ligands with uncharged amine-pyridine donors, obtained by cyclic voltammetry, have to be considered with caution.

scholarly journals Investigation of Electrochemical Behaviour of Quercetin on the Modified Electrode Surfaces with Procaine and Aminophenyl in Non-Aquous Medium

2008 ◽  
Vol 5 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Ibrahim Ender Mulazimoglu ◽  
Erdal Ozkan
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Glassy Carbon ◽  
Electrode Surface ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Carbon Electrode ◽  
Amine Group ◽  
Tetrabutylammonium Tetrafluoroborate

In this study, cyclic voltammetry and electrochemical ımpedance spectroscopy have been used to investigate the electrochemical behaviour of quercetin (3,3′,4′,5,7-pentahydroxyflavone) on the procaine and aminophenyl modified electrode. The modification of procaine and aminophenyl binded electrode surface with quercetin was performed in +0,3/+2,8 V (for procaine) and +0,4/+1,5 V (for aminophenyl) potential range using 100 mV s-1scanning rate having 10 cycle. A solution of 0.1 M tetrabutylammonium tetrafluoroborate in acetonitrile was used as a non-aquous solvent. For the modification process a solution of 1 mM quercetin in 0.1 M tetrabutylammonium tetrafluoroborate was used. In order to obtain these two surface, a solution of 1 mM procaine and 1 mM nitrophenyl diazonium salt in 0.1 M tetrabutylammonium tetrafluoroborate was used. By using these solutions bare glassy carbon electrode surface was modified. Nitrophenyl was reduced to amine group in 0.1 M HCl medium on the nitrophenyl modified glassy carbon elelctrode surface. Procaine modified glassy carbon electrode surface was quite electroactive. Although nitrophenyl modified glassy carbon elelctrode surface was electroinactive, it was activated by reducing nitro group into amine group. For the characterization of the modified surface 1 mM ferrocene in 0.1 M tetrabutylammonium tetrafluoroborate for cyclic voltammetry and 1 mM ferricyanide/ferrocyanide (1:1) mixture in 0,1 M KCl for electrochemical impedance spectroscopy were used.

CARBON NANOTUBES USED IN ELECTROANALYSIS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 603-605 ◽  
Author(s):  
C. G. HU ◽  
B. FENG
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Experimental Period ◽  
Cyclic Voltammograms ◽  
Alkaline Aqueous Solution ◽  
Routine Monitoring ◽  
Good Signal ◽  
Better Than

The fabrication of the carboxyl-modified CNT electrode was described. The electroanalytical investigation of sulfadiazine has been conducted in alkaline aqueous solution at the CNT electrode by voltammetry. Highly reproducible and well-defined cyclic voltammograms were obtained for sulfadiazine with a very good signal to background (S/B) ratio. However, no fouling of the electrode was observed at the CNT electrode within the experimental period of several hours, which illustrated that the CNT electrode was much better than traditional electrodes. Meanwhile, the detection of trace sulfadiazine in milk was also conducted by cyclic voltammetry with satisfactory ratio of recovery, indicating that the nanotube electrode can be used in routine monitoring of sulfadiazine residues in food.

The Effect of Appending of I-，Fe2+ and MnO4- to the Electro-Oxidation of Methanol on Platinum Electrode

2012 ◽  
Vol 608-609 ◽  
pp. 894-897
Author(s):  
Hai Tao Wang ◽  
Zhen Jin ◽  
Yu Chun Qin
Keyword(s):  
Aqueous Solution ◽  
Electrode Surface ◽  
Platinum Electrode ◽  
Cyclic Voltammograms ◽  
Pt Electrode ◽  
Promotion Effect ◽  
Oxidation Current ◽  
Oxidation Of Methanol ◽  
Electronic Distribution ◽  
Electro Oxidation

Three kinds of ions (I-、Fe2+and MnO4-) were appended into the methanol aqueous solution respectively as an additive and the Cyclic voltammograms of the aqueous solutions were studied. The results showed that Fe2+had obvious promotion effect for electro-oxidation of methanol and could improve the methanol anodic oxidation current by 85 percent. The promotion effect of the thulium Ions were related with the electronic distribution of these elements and their adsorption on the Pt electrode surface. I-and MnO4-could facilitate the electro-oxidation of methanol at different extent.

Oxidation pathways of natural dye hematoxylin in aqueous solution

2010 ◽  
Vol 75 (11) ◽  
pp. 1097-1114 ◽  
Author(s):  
Romana Sokolová ◽  
Ilaria Degano ◽  
Magdaléna Hromadová ◽  
Jana Bulíčková ◽  
Miroslav Gál ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Gas Chromatography ◽  
Cyclic Voltammetry ◽  
Dissociation Constants ◽  
Dye Degradation ◽  
Oxidation Mechanism ◽  
Oxidation Products ◽  
Mass Spectrometry Detection ◽  
Vis Spectroscopy

The oxidation mechanism of hematoxylin was studied in phosphate buffers and 0.1 M KCl by cyclic voltammetry and UV-Vis spectroscopy under deaerated conditions. The redox potential of hematoxylin in buffered solution strongly depends on pH. A two electron oxidation is preceded by deprotonation. The homogeneous rate of deprotonation process of hematoxylin in 0.1 M phosphate buffer is kd = (2.5 ± 0.1) × 104 s–1. The cyclic voltammetry under unbuffered conditions shows the distribution of various dissociation forms of hematoxylin. The dissociation constants pK1 = 4.7 ± 0.2 and pK2 = 9.6 ± 0.1 were determined using UV-Vis spectroscopy. The final oxidation product was identified by gas chromatography with mass spectrometry detection as hemathein. The distribution of oxidation products differs under buffered and unbuffered conditions. The dye degradation in natural unbuffered environment yields hemathein and hydroxyhematoxylin, which is absent in buffered solution.

Electrochemical Reaction Mechanism of Tiron in Acidic Aqueous Solution

2011 ◽  
Vol 396-398 ◽  
pp. 1730-1735 ◽  
Author(s):  
Yan Xu ◽  
Yue Hua Wen ◽  
Jie Cheng ◽  
Gao Ping Cao ◽  
Yu Sheng Yang
Keyword(s):  
Aqueous Solution ◽  
Cyclic Voltammetry ◽  
Aqueous Solutions ◽  
Electrochemical Oxidation ◽  
Electrochemical Reaction ◽  
Mass Spectrometric ◽  
Acidic Aqueous Solution ◽  
Ece Mechanism ◽  
Flow Through ◽  
Electro Oxidation

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.

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