Catalytic and Kinetic Waves in Polarography

Mairanovskii, S. G.

doi:10.1007/978-1-4899-2831-3

Cited by 129 publications

(80 citation statements)

References 275 publications

(600 reference statements)

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“…This is because an increase of the rate constant of protonation of the catalyst is compensated by a decrease in its adsorptivity on the electrode surface 17 .…”

Section: Resultsmentioning

confidence: 99%

Dithiocarbamates as Selective Ligands for Polarographic Study of Manganese(II) at DME

Giridhar¹,

Kanchi²,

Niranjan³

et al. 2014

Chem Sci Trans

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Abstract:Two new ligands, ammonium 2,6-dimethyl morpholine dithiocarbamate (ADMM-DTC) and ammonium 3-methyl piperdine dithiocarbamate (AMP-DTC) were synthesized in the laboratory. The method was based on chelation of manganese(II) with ADMM-DTC/AMP-DTC in the presence of NH 4 OH at pH 6.2 and 6.8 to produce catalytic hydrogen currents at -0.72 V and -0.62 V vs. SCE respectively and prior detected by D.C poarography. Optimized polarographic conditions were established by studying effect of pH, supporting electrolyte (NH 4 Cl), ligand and metal ion concentrations and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the present method. This technique is successfully applied for the analysis of manganese(II) in different matrices with recoveries ranging from 97 -99% and the results obtained were comparable with the differential pulse polarography (DPP).

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“…This is because an increase of the rate constant of protonation of the catalyst is compensated by a decrease in its adsorptivity on the electrode surface 17 .…”

Section: Resultsmentioning

confidence: 99%

Dithiocarbamates as Selective Ligands for Polarographic Study of Manganese(II) at DME

Giridhar¹,

Kanchi²,

Niranjan³

et al. 2014

Chem Sci Trans

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“…28. It shows the presence of a single species and the parameters are indicative of an axial geometry at variance with wild-type superoxide dismutase which is highly rhombic (Fig.…”

Section: Spectroscopic Characterization the Cu Zn Derivative Cu Znmentioning

confidence: 94%

“…Measurements were performed at 0.002 V/s, with a pulse amplitude (AE) of 35 mV. The El,, value was obtained by applying the Parry-Osteryoung relationship Ep = El,,-AE/2 that relates the peak potential E, to the half-wave potential El,, for a given pulse amplitude AE [28]. The reversibility of the process was evaluated from the half-peak width.…”

Section: Experimental Procedures Sample Preparationmentioning

confidence: 99%

Mutation of the Metal‐Bridging Proton‐Donor His63 Residue in Human Cu, Zn Superoxide Dismutase

Banci¹,

Bertini²,

Borsari³

et al. 1995

European Journal of Biochemistry

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The bridging His63 residue in human Cu, Zn superoxide dismutase, which binds both metals, has been replaced by a Cys residue. The mutant protein has been purified from Escherichia coti and appears to be a normal dimer. Spectroscopic techniques (electronic spectroscopies, EPR, nuclear magnetic relaxation dispersion) show that Cys63 binds the zinc ion, but not the copper ion, and that the latter is probably five co-ordinated with three histidine ligands and two water molecules. The reduction potential of the copper ion in the Cuz'/Cu' pair decreases from 0.41 V to 0.27 V at neutral pH but still remains intermediate between those of the O,/O; and O;/H,O, pairs so that copper can both oxidize and reduce the 0; substrate, a requirement for dismutase activity. The enzyme binds the substrate-analogue azide (N;), which displaces one water molecule, with near normal affinity, whereas the enzyme activity with the 0; substrate is reduced to less than 1 % of wild-type levels at pH 7.8. The properties of the mutant enzyme are discussed in relation to the superoxide-copper electron transfer process and to the catalytic mechanism.

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“…Appropriate conformation of the catalyst near the electrode with respect to the electrode double layer is the decisive condition of the process. 6 A hydrogen evolution catalyst of the »presodium« type is either a species stable in the solution or an intermediate in cathodic electrode reaction of a reducible substance, which catalyses hydrogen evolution in the course of its lifetime within a limited potential span. 7 …”

Section: »Presodium« Catalysismentioning

confidence: 99%