An electrochemical investigation on mononuclear and dinuclear copper(I) aminocarbonyl complexes

1985 ◽  
Vol 63 (4) ◽  
pp. 922-927 ◽  
Author(s):  
Piero zanello ◽  
Piero leoni
Keyword(s):  
Carbon Monoxide ◽  
Electrochemical Behaviour ◽  
Platinum Electrodes ◽  
Electron Charge ◽  
Electrochemical Investigation ◽  
Carbonyl Derivatives ◽  
Dimethyl Sulfoxide Solution ◽  
Controlled Potential ◽  
Cathodic Processes ◽  
Controlled Potential Coulometry

The electrochemical behaviour of some copper(I) aminocarbonyl derivatives, namely, [Cu(dien)(CO)]+ (dien = diethylenetriamine), [Cu(Medpt)(CO)]+ (Medpt = N,N-bis(3-aminopropyl)methylamine), [Cu2(tmen)2(μ-PhCO2)(μ-CO)]+ (tmen = N,N,N′,N′-tetramethylethylenediamine), has been studied in dimethyl sulfoxide solution at platinum electrodes by cyclic and dc voltammetry, and controlled potential coulometry. In all studied complexes each copper(I) centre undergoes one-electron charge transfers in both anodic and cathodic processes. The electrogenerated copper(II) complexes, fully characterized, can be reversibly reduced to the starting copper(I) carbonyl derivatives in the presence of carbon monoxide. The electron-transfer sequences in which these copper(I) complexes may be involved have been elucidated.

Effect of ligand structure, solvent, and temperature on the electrochemical behavior of polyarene–iron complexes

1996 ◽  
Vol 74 (5) ◽  
pp. 650-657 ◽  
Author(s):  
Alaa S. Abd-Ei-Aziz ◽  
Christine R. De Denus ◽  
Karen M. Epp ◽  
Simone Smith ◽  
Richard J. Jaeger ◽  
...  
Keyword(s):  
Reduction Process ◽  
Iron Complexes ◽  
Electrochemical Investigation ◽  
Dissociative Mechanism ◽  
Bridging Ligand ◽  
Controlled Potential ◽  
Degree Of Stability ◽  
Arene Ligand ◽  
Redox Centers ◽  
Controlled Potential Coulometry

The electrochemical investigation of a number of polyarene–iron complexes ([3]2+–[9]5+) containing etheric, sulphide, and sulphone bridges indicated that there were various degrees of interaction based on the nature of the bridging heteroatoms. While the electrochemical investigation of all etheric complexes showed that the metallic moieties behaved as isolated redox centers, it was found that there was electronic communication (ca. 70–80 mV) for the isomeric sulphide complexes [4]2+ and [6]2+. The rate constant of the following chemical reaction (kf) was calculated for some of these complexes and it was found that these rates were affected by the nature of the solvent, the bridging ligand, and the temperature. At various temperatures, kf indicated a higher degree of stability for complexes containing sulphide bridges than for those containing etheric bridges, especially at room temperature. The effect of a strong coordinating solvent, such as acetonitrile, on the kf of complex [3]2+ indicated that the substitution of the arene ligand with acetonitrile molecules proceeded as a dissociative mechanism. Controlled potential coulometry was also used to verify the transfer of two electrons in the first reduction process of the di-iron complexes. Key words: cyclopentadienyliron, cyclic voltammetry, arene complexes, isolated and interacting redox centers.

Electrochemical studies of amine salts of monothiocarbamates

1982 ◽  
Vol 35 (12) ◽  
pp. 2465
Author(s):  
RJ Magee ◽  
B Annuar
Keyword(s):  
Electrochemical Behaviour ◽  
Mercury Electrode ◽  
Compact Layer ◽  
Cyclic Voltammetric ◽  
Reactive Material ◽  
Anodic Wave ◽  
Diffusion Controlled ◽  
Controlled Potential ◽  
Controlled Potential Coulometry ◽  
Amine Salts

The electrochemical behaviour of the amine salts of morpholyl-, pyrrolidyl-�and piperidyl-mono- thiocarbamates (morpholinium morpholine-4-carbothioate, piperidinium piperidine-1-carbothioate and pyrrolidinium pyrrolidine-1-carbothioate) at the mercury electrode has been studied by means of d.c. polarography and cyclic voltammetry. All three exhibited a well defined anodic wave, but the pyrrolidyl derivative (pymtc) gave an additional wave. The main wave in each case was found to be diffusion-controlled. Temperature coefficients showed erratic behaviour at higher temperatures which was thought to be due to decreasing availability of reactive material because of decomposition. Controlled potential coulometry gave n = 1 per mole for the main wave of each compound. The behaviour was similar to that of the dithiocarbamate ligands under the same conditions and the small pre-wave in the polarograms of pymtc is attributed to the formation of a mercuric pyrrolidyl monothiocarbamate, which, unlike the mercuric complex of the other two ligands is structurally ordered and able to form a compact layer with the electrode. Cyclic voltammetric results supported the findings of polarography and confirmed the following mechanism: mtc- + Hg → Hg(mtc) + e' (1) 2Hg(mtc) → Hg(mtc)2 + Hg (2)

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.

Determination of titanium by controlled-potential coulometry

1971 ◽  
Vol 43 (6) ◽  
pp. 747-751 ◽  
Author(s):  
Lester P. Rigdon ◽  
Jackson E. Harrar
Keyword(s):  
Controlled Potential ◽  
Controlled Potential Coulometry

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.

Investigation of the Role of Carbonylchemistry to Pattern Platinum Electrodes

2001 ◽  
Vol 688 ◽  
Author(s):  
St. Schneider ◽  
H. Kohlstedt ◽  
R. Waser
Keyword(s):  
Carbon Monoxide ◽  
Etch Rate ◽  
Noble Metals ◽  
Electrode Materials ◽  
In Situ Monitoring ◽  
Platinum Electrodes ◽  
Process Chemistry ◽  
Dimension Control ◽  
Axis Position

AbstractNoble metals like platinum or irdium are used as electrode materials in DRAM or FRAM devices. Their etch process is a challenge as conventional, sputter driven etch processes either result in redeposition problems (fences) or in a severe sloping (loss of dimension control) and are not acceptable for high density integration architectures. The high temperature etch regime offers a solution by increasing the chemical etch component and thus the volatility of the etch products.As previously reported, the platinum etch rate increases exponentially for a chlorine etch process with increasing wafer temperature. In this study we investigate the particular role of carbon monoxide in a Cl2/CO etch process. We find that carbon monoxide additions to a chlorine process boost the chemical component of the platinum etch rate very significantly, exceeding the effects in the chlorine only process regime by far. Additionally we compare these results with a Cl2/O2 and a Cl2/CO2 process chemistry, which are not found to be particularly beneficial.To better understand the etch process we use an energy dispersive quadrupole mass spectrometer for in situ monitoring, attached to the chamber at two different locations. We are able to position the probe orifice at the place of the wafer electrode, to record ion energy and ion mass spectra of species impinging on the wafer plane. A second off axis position allows for etch product monitoring.

Real-time computer prediction of end points in controlled-potential coulometry

1970 ◽  
Vol 42 (7) ◽  
pp. 764-774 ◽  
Author(s):  
Frederick B. Stephens ◽  
Fredi. Jakob ◽  
L. P. Rigdon ◽  
Jackson E. Harrar
Keyword(s):  
Real Time ◽  
Computer Prediction ◽  
End Points ◽  
Controlled Potential ◽  
Controlled Potential Coulometry
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