Substituent effect in electrochemical and ferricyanide oxidations of para-substituted 1-benzyl-3-carbamoyl-1,4-dihydropyridines

1983 ◽  
Vol 48 (5) ◽  
pp. 1408-1421 ◽  
Author(s):  
Františka Pavlíková-Raclová ◽  
Josef Kuthan
Keyword(s):  
Electrochemical Oxidation ◽  
Rate Constants ◽  
Substituent Effect ◽  
Potassium Ferricyanide ◽  
Rotating Disc Electrode ◽  
Disc Electrode ◽  
Rotating Disc ◽  
Half Wave ◽  
Substituted 1 ◽  
Dihydropyridine Derivatives

Half-wave potentials E1/2 of electrochemical oxidation of the title 1,4-dihydropyridine derivatives with the substituents N(CH3)2, OCH3, CH3, H, F, Cl, COOCH3, and CN have been measured on platinum rotating disc electrode in aqueous and anhydrous dimethylformamide, and apparent rate constants k2 of their oxidation with potassium ferricyanide have been measured in water at 298 K. The two quantities (E1/2 and k2) have been correlated both mutually and with empirical σp constants of the substituents. The found correlation relations have been discussed with respect to mechanism of the two transformations investigated.

Substituent effect in addition of cyanide ion to p-substituted 1-benzyl-3-carbamoylpyridinium chlorides

1983 ◽  
Vol 48 (5) ◽  
pp. 1401-1407 ◽  
Author(s):  
Františka Pavlíková-Raclová ◽  
Josef Kuthan
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Substituent Effect ◽  
Equilibrium Constants ◽  
Substituent Effects ◽  
Cyanide Ion ◽  
Quaternary Salts ◽  
Half Wave ◽  
Substituted 1 ◽  
Mechanism Of The Reaction

The rate constants k2 and equilibrium constants K = k2/k-2 of the title process (A) have been measured in aqueous solutions of eight quaternary salts of nicotinamide I (R = p-XC6H4CH2) at 298 K. The substituent effects of X = CH3O, CH3, H, F, Cl, COOCH3, CN, and NO2 exhibiting the Hammett dependence have been correlated with half-wave potentials of reduction of the depolarizers I, and the correlation results have been discussed with respect to mechanism of the reaction (A).

Bromate Reaction on a Rotating Disc Electrode: A New Method of Obtaining Approximate Analytical Solutions for Stationary Regime

2018 ◽  
Vol 483 (1) ◽  
pp. 256-260
Author(s):  
M. A. Vorotyntsev ◽  
A. E. Antipov ◽  
M. M. Petrov ◽  
R. D. Pichugov ◽  
E. I. Borisevich ◽  
...  
Keyword(s):  
Analytical Solutions ◽  
Stationary Regime ◽  
New Method ◽  
Rotating Disc Electrode ◽  
Disc Electrode ◽  
Rotating Disc ◽  
Approximate Analytical Solutions

scholarly journals Redox Property Tuning in Bipyridinium Salts

2021 ◽  
Vol 8 ◽  
Author(s):  
Zuzana Burešová ◽  
Milan Klikar ◽  
Petr Mazúr ◽  
Michaela Mikešová ◽  
Jaroslav Kvíčala ◽  
...  
Keyword(s):  
Redox Processes ◽  
Rotating Disc Electrode ◽  
Structure Property ◽  
Disc Electrode ◽  
Rotating Disc ◽  
Half Cell ◽  
Redox Flow Batteries ◽  
Structure Property Relationships ◽  
Reversible Redox ◽  
Small Capacity

Bipyridinium salts are currently very popular due to their perspective applications in redox flow batteries. Hence, we designed and prepared a series of bipyridiniums based on 2,2′-, 3,3′-, and 4,4′-bipyridine and 2,2′-bipyrimidine. The straightforward synthesis utilizes commercially or readily available starting compounds and their direct N-alkylation, mostly using 1,3-propanesultone. All eleven target derivatives with systematically evolved structure were investigated by cyclic voltammetry, which allowed elucidating thorough structure-property relationships. The electrochemical behavior depends primarily on the parent scaffold, type of N-alkylation, number of quaternized nitrogen atoms, planarity, counter ion as well as the used media. Two derivatives featuring quasi-reversible redox processes were further tested on rotating disc electrode and in a flow battery half-cell. 4,4′-Bipyridinium derivative bearing two sultone residues showed better performance and stability in the flow half-cell with small capacity decays of 0.09/0.15% per reduction-oxidation cycle, based on the number of the utilized redox processes (one/two).

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