Electrochemistry of Ruthenium Bis(imino)pyridine Compounds: Evidence for an ECE Mechanism and Isolation of Mono and Dicationic Complexes

2017 ◽  
Vol 57 (1) ◽  
pp. 435-445 ◽  
Author(s):  
Michael E. Noss ◽  
Anne T. Hylden ◽  
Patrick J. Carroll ◽  
Donald H. Berry
Keyword(s):  
Ece Mechanism

Electroanalytical chemistry of vanadium complexes. Comparison of the voltammetric features of amavadine with those of the vanadium complexes with iminodiacetic acid and methyliminodiacetic acid

1989 ◽  
Vol 54 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Roland Meier ◽  
Harald Frank ◽  
Reinhard Kirmse ◽  
Reiner Salzer ◽  
Joachim Stach ◽  
...  
Keyword(s):  
Iminodiacetic Acid ◽  
Vanadium Complexes ◽  
Reduction Mechanism ◽  
Reversible Process ◽  
Electroanalytical Chemistry ◽  
Probable Explanation ◽  
Chemical Sense ◽  
Ece Mechanism ◽  
Methyliminodiacetic Acid

The voltammetric behaviour of amavadine (AV) was found to be considerably different from that of the complexes of VO2+ with methyliminodiacetic acid (MIDA) and iminodiacetic acid (IDA). To get an insight in the rather complicated reduction mechanism of the latter complexes the reductions of V(III) (MIDA) and V(III) (IDA) have been studied for comparison. The species V(III) (MIDA)2 and V(III) (IDA)2 are reduced to the appropriate V(II) complexes in a chemically reversible process. VO(MIDA)2 and VO(IDA)2 are reduced to the same complexes via an ECE mechanism. The investigation of the electroreduction of AV shows that this process is not reversible in the chemical sense. As a probable explanation, the conclusion was drawn that AV and the usual V(IV)O-iminocarboxylato complexes differ in their structures.

Synthesis and Electrochemical Reduction of Methyl 3-Halo-1-benzothiophene-2-carboxylates

2004 ◽  
Vol 69 (1) ◽  
pp. 242-260 ◽  
Author(s):  
Michal Rejňák ◽  
Jiří Klíma ◽  
Jiří Svoboda ◽  
Jiří Ludvík
Keyword(s):  
Cyclic Voltammetry ◽  
Radical Anion ◽  
Preparative Method ◽  
Platinum Electrodes ◽  
Disk Electrode ◽  
Dimer Formation ◽  
Halide Anion ◽  
Primary Radical ◽  
Heterocyclic Radical ◽  
Ece Mechanism

A preparative method of synthesis of the new methyl 3-iodo-1-benzothiophene-2-carboxylate was elaborated. Electrochemical behavior of methyl 3-chloro-, bromo- and iodo-1-benzothiophene-2-carboxylates 1-3, and of their reduction and dimer products 4, 5 in anhydrous dimethylformamide has been investigated at mercury and platinum electrodes using polarography, cyclic voltammetry and voltammetry on a rotating platinum disk electrode. The reduction in divided cells follows the ECE mechanism (electron - chemical step - electron), where the primary radical anion is split into a halide anion and neutral heterocyclic radical, which is immediately reduced by the second electron and protonated. The only reduction product is the methyl 1-benzothiophene-2-carboxylate (5); whereas the EDim mechanism (electron - dimer formation) leading to the dimeric species 4 was not observed under the above conditions. Reduction of 1-3 on platinum causes formation of a blocking film on the electrode. Sonication during electrolysis successfully reactivates the electrode.

ECE mechanism as a tool for the investigation of unstable metal complexes

1980 ◽  
Vol 107 (1) ◽  
pp. 95-103 ◽  
Author(s):  
N. Tanaka ◽  
T. Yoshikuni ◽  
Y. Kato ◽  
A. Yamada
Keyword(s):  
Metal Complexes ◽  
Ece Mechanism

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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