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Volume 46, Issue 1
Displaying 1-6 of 6 articles from this issue
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Taitiro Fujinaga2000 Volume 46 Issue 1 Pages 1-2
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (359K) -
Hirosuke TATSUMI2000 Volume 46 Issue 1 Pages 3-7
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
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Masashi Hojo2000 Volume 46 Issue 1 Pages 9-15
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn poor solvating media, unexpected large chemical bonding forces of alkali metal ions, especially Li+, have been revealed. The chemical bonding forces of alkali metal ions and its effects on chemical equilibria and reaction rates in solution are reviewed. The complex formation constants of alkali metal ions with carboxylate ions as well as macrocyclic polyetheramines (L) in acetonitrile were obtained by the analysis of the shift in E1/2 of the mercury-dissolution wave of L. The higher ion aggregation, i.e., the formation of triple ions and quadrupoles, from 1:1 salts in higher permittivity solvents (εr>10) was demonstrated by conductometry and spectrophotometry. The salt effects on the indicator acidity in acetonitrile have been attributed to the chemical interaction with the alkali metal ions (M+), alkaline earth metal ions (M2+), or anions. Stable carbocations were produced from (4-methoxy-substituted) trityl halides in acetonitrile, making use of the direct interaction between M+ of M2+ and the halide ions. A mixed-anion salt, BaCl(ClO4), was isolated from acetonitrile solution. The concentrated salt effects on the solvolysis reaction rates of organic halides (RX) in water-mixed solvents have been explained in terms of the direct interaction between M+ or M2+ and X-, and not just of medium effects. Alteration of the bulk water to isolated water molecules in the presence of concentrated salts is proposed.View full abstractDownload PDF (1010K) -
Application of Infrared Spectroscopy to the Structural Studies of Electrode | Electrolyte InterfacesFusao MTAMURA2000 Volume 46 Issue 1 Pages 17-24
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSInfrared spectroscopic studies on the double layer structure at the electrode | electrolyte interface are reviewed. There are three approaches to investigate the interfacial structure, i.e., non situ, ex situ and in situ methods. Infrared reflection absorption spectra (IRAS) obtained on model structures constructed non situ under UHV condition are helpful to understand the potential-dependent change in adlayer structure in the electrolyte solution. Recent studies on the interfacial water molecule using in situ infrared spectroscopic techniques are also quoted briefly.View full abstractDownload PDF (2589K) -
Kenji Yokoyama2000 Volume 46 Issue 1 Pages 25-34
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA cyclic voltammetric simulation that can be applied to an electrochemically mediated enzyme reaction involving any substrate and mediator concentrations was reviewed. Concentration polarization of the substrate in the vicinity of an electrode was considered as well as mediator concentration. Reversible and quasi-reversible electrochemical reactions with one electron followed by an enzyme reaction with two electrons were modeled. The differential equations for the mediator and substrate were solved using digital simulation techniques. The calculated cyclic voltammograms showed prepeaks when there was a low substrate concentration, high mediator concentration, and high enzyme activity. Digital simulation was applied to the determination of the kinetic constants of glucose oxidase (GOx). Cyclic voltammetry was carried out experimentally in a phosphate buffer solution containing GOx, ferrocene derivatives, and glucose. The ratio of the catalytic to the diffusion-controlled current, ik/id, was evaluated. The kcat, KMM, and KMS values were determined from the current values obtained by simulation and by experimentation at various enzyme, mediator, and substrate concentrations.View full abstractDownload PDF (1315K) -
Kohji MAEDA2000 Volume 46 Issue 1 Pages 35-52
Published: May 01, 2000
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe mechanisms for the oscillation of membrane potential or membrane current accompanied by ion transport through a membrane were investigated with the aid of ion transfer voltammetry at an aqueous/organic or aqueous/membrane interface. The current or potential oscillation that occurs by applying constant membrane potential or current and the spontaneous oscillation of membrane potential without any motive force by outside circuit were examined. Both oscillatoos involves the ion transfer that causes the maximum current in voltammogram at an aqueous/membrane interface. The change of membrane potential during the oscillation was connected to the ion transfer potentials at two aqueous/membrane interfaces.View full abstractDownload PDF (3138K)
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