bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Aspects of a NADH/FAD Model System
Authors: Sasaki Kazuo , Kitani Akira , Kunai Atsutaka , Miyake Hitoshi 
Published: July 2006

Abstract
A model system of the NADH/FAD redox couple has been studied by the use of electrochemical techniques. The system studied was composed of 1-benzyl-1,4-dihydronicotinamide (BNAH) and riboflavin (RF), which were used in place of NADH and FAD respectively, dissolved in a DMSO solution. The results obtained were as follows. RF is reduced either by BNAH or sodium borohydride, obeying a second-order rate law, presumably by the mechanism of hydride-ion transfer. The resultant product is inactive to the electrochemical reduction at a mercury-pool electrode. Entirely different products were produced when RF was reduced electrochemically. RF was reduced at a rate of 1 F/mol at the initial stage of controlled potential electrolysis to form, probably, a dimeric compound, but the latter product underwent further reduction and the total quantity of electricity necessary for the complete reduction exceeded 10 F/mol. Interestingly, the electrolytic reduction gives the same product as that obtained by BNAH when electrolysis is performed in the presence of a sufficient amount of BNAH, indicating that the initial product of electrochemical reduction receives the hydride ion rather than further electrons.
2RF+2e\ightleftarrows(RF)_2^2-\overset+H^-,+H^+→2RFH^-
The Zn2+ added to the BNAH/RF system was found to act as the oxidizing agent of RFH− and regenerated the neutral RF. This is markedly different from the case of BNAH/organic carbonyl compounds, where the metal ions behave as catalysts to promote the reaction.
A Contribution to the Theory of Pulse Polarography. I. Theory of Current-Potential Curves
Authors: Matsuda Hiroaki 
Published: July 2006

Abstract
A general theory of pulse polarographic current-potential curves is developed for a simple electrode reaction proceeding at the expanding plane electrode. It is shown that when the ratio of the sampling time to the pre-electrolysis time is smaller than 1/30, this condition being satisfied in usual pulse polarographic practice, the equation of current-potential curves can be greatly simplified. The theory developed is applied to the three modes of pulse polarography nowadays practically employed, i.e., normal pulse, scan-reversal pulse and differential pulse polarography. For each mode, the dependence of current-potential curves on the kinetic parameters of electrode reaction as well as on the experimental variables is discussed.
Adsorption of Alkaline Earth Cations on Mercury as Studied with the Perbromate Kinetic Probe
Authors: Osaka Tetsuya , de Levie Robert 
Published: July 2006

Abstract
Reduction of perbromate was used as a kinetic probe of double layer parameters for weak specific adsorption of double layer parameters for weak specific adsorption of alkaline earth cations at the mercury/electrolyte solutions interface. The results are interpreted as evidence for weak specific adsorption of Sr2+ and particularly Ba2+ in 10 mM solutions at negative electrode charge densities. The limitation of the use of an anionic probe for the quantitation of cation specific adsorption is discussed.
Infrared Multiple Photon Dissociation of Cyclobutanone
Authors: Koda Seiichiro , Ohnuma Yasushi , Ohkawa Tadashi , Tsuchiya Soji 
Published: July 2006

Abstract
The multiple photon dissociation of cyclobutanone was discussed on the basis of the observed relative significance of two reaction channels. Cyclobutanone was irradiated by a TEA CO2 laser beam of 9.6 μm R(14) line in a parallel and a focussed geometry. The detected products were ethylene, ketene, and cyclopropane under parallel geometry irradiation. Propylene and acetylene were also produced in focussed geometry irradiation. The kind of the products as well as the effects of reaction conditions on their yields led to the conclusion that the dissociation proceeds along two channels, in one of which ethylene and ketene are produced and in the other cyclopropane and CO. The experimental results agreed almost with the result simulated by a statistical model calculation based on the hypothesis that the energy absorbed in cyclobutanone molecules is statistically distributed among all vibrational degrees-of-freedom.
1H NMR Study of Interaction of Probe Molecules with the Phosphate Ion on the Iron Core of Horse Spleen Ferritin
Authors: Imai Noboru , Arata Yoji , Fujiwara Shizuo 
Published: July 2006

Abstract
The surface of the iron core of ferritin was investigated by 1H NMR using small probe molecules which have different sizes and charges. It was shown that the parameter k, which is the linewidth for each NMR probe normalized by the total concentration of iron in ferritin, is dependent on the content of phosphorus in ferritin. At pH 7.4, the k values are 1–10 for positively charged probes, 2×10−2–8×10−2 for negatively charged probes and 0.1–0.2 for neutral probes. Above pH 7, the k values for positively charged probes increase with an increase in pH, whereas those for negatively charged probes decrease. By contrast, the k values for neutral probes remain constant over the entire pH range. It was concluded that the k values reflect the mode of interactions of small molecules with the phosphate which exists on the surface on the iron core of ferritin, and that these interactions are determined primarily by the electrostatic force between the small molecules and the negative charge of the phosphate of ferritin. Furthermore, it was shown by using t-butylamine as a probe that K+ ion binds strongly to ferritin and that chelating agents interact with ferritin in a wide concentration range.
Proton Magnetic Resonance Study of Interaction between Penicillin G and Hen Egg White Lysozyme
Authors: Mitsumori Fumiyuki , Arata Yoji , Fujiwara Shizuo 
Published: July 2006

Abstract
Interaction between penicillin G and hen egg white lysozyme has been studied using NMR and gel chromatography. It has been demonstrated that the stoichiometry of the interaction is one to one with an association constant of approximately 1.9×102 M−1 (1M=lmol dm−3). It has also been shown that the phenacyl side chain of penicillin G is interacting with the tryptophan-123 residue of the lysozyme molecule.
Studies of Inorganic Ion Exchangers. V. The Preparation of the Granulated Product from Titanium(IV) Bis(hydrogenphosphate) and Carbonaceous Materials, and Its Ion-exchange Properties
Authors: Kobayashi Etsuro , Kanayama Tadao 
Published: July 2006

Abstract
In order to develop an inorganic ion exchanger for industrial use, a mixture of titanium(IV) bis (hydrogenphosphate), a carbonaceous material (sugar, flour, or sodium ligninsulfonate), and an additive (H2SO4 or H3PO4) was sintered, and the resultant sintered product was crushed to obtain a granulated product, the ion-exchange property of which was then investigated. The mixing ratio of the titanium phosphate to the carbonaceous material has an influence on the ion-exchange capacity and the durability of the granulated product. In consideration of this influence, the weight ratio of the titanium phosphate to carbon included in the carbonaceous material was expediently chosen as 1 : 0.5. The acid additives promoted the carbonization of the carbonaceous material, whereby the sintered product of porosity was obtained. The weight ratio of the carbonaceous part to the titanium phosphate in the product decreased with an increase in the temperature within the range from 185 to 350 °C. In a batch method, a granulated product including Ti(HPO4)2·H2O adsorbed Na+, but not K+. A granulated product including Ti(HPO4)2·1/2H2O, however, adsorbed these ions, the equilibrium ion-exchange capacities toward Na+ and K+ being 1.28–1.78 and 1.56–2.34 meq/g respectively, and the selectivity quotient and the distribution coefficient toward K+ showed larger values than those toward Na+. In a column method, when a NaCl (26.66 g/l)KCl (0.67 g/l) aqueous solution flowed into a column which had been packed with the granulated product (5 g) including the hemihydrate, the ion-exchange capacities of this granulated product toward Na+ and K+ were 1.1–1.2 and 0.38–0.58 meq/g, respectively, showing the separation factor (αNaK) of 18–25. When artificial brackish water also flowed into the column, very small quantities of the Mg2+ and Ca2+ were adsorbed; consequently, a selective ion-exchange property of the granulated product toward K+ was recognized. Also, the carbonaceous part in the granulated product adsorbed such coloring matter as Methylene Blue.
Studies on High-pressure Reaction of Er2O3 or Yb2O3 with VO2
Authors: Shin-ike Tsutomu , Adachi Gin-ya , Shiokawa Jiro , Shimada Masahiko , Koizumi Mitsue 
Published: July 2006

Abstract
The reaction of erbium sesquioxide (Er2O3) or ytterbium sesquioxide (Yb2O3) with vanadium dioxide (VO2) at 1400 °C and 50 kbar and 30 kbar pressures was studied. Quadrivalent vanadium ions were reduced to the trivalent state, erbium vanadite (ErVO3) or ytterbium vanadite (YbVO3) being obtained. The crystal structure of ErVO3 obtained at 50 kbar pressure was vaterite-type isostructural with ErBO3 belonging to a hexagonal system, and that obtained at 30 kbar calcite-type belonging to a rhombohedral (pseudo-hexagonal) system. In the reaction of Yb2O3 with VO2 at high pressure, a perovskite-type crystal was obtained. The electrical and magnetic properties of the vaterite- and the calcite-type ErVO3 were studied.
Solubility Isotherms of Systems Containing Optically Active Tris(ethylenediamine)cobalt(III) Ion. I. Reciprocal Salt-pairs, (Λ-[Co(en)3]3+, Δ-[Co(en)3]3+)–(Br−, (R,R)-C4H4O62−), at 25 °C
Authors: Fuyuhiro Akira , Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
A four-component solubility isotherm consisting of (Λ-[Co(en)3]3+, Δ[Co(en)3]3+)–(Br−,(R,R)-C4H4O62−)–H2O was determined at 25 °C. It was found that three double salts, rac-[Co(en)3]Br3·3H2O, Λ-[Co(en)3]Br(d-C4H4O6)·5H2O, and Λ-[Co(en)3]0.48·Δ-[Co(en)3]0.52(d-C4H4O6)1.5·5H2O and a gelatinous precipitate exist, six invariant points appearing. Application of this phase diagram to practical optical resolutions is discussed. The solubility of each salt in the system was measured in the range 5–65 °C in water, that of Λ and Δ-[Co(en)3](d-C4H4O6)1.5·nH2O being found to be reversed at 42 °C.
Resonance Raman Spectra of Tetracyanoethylene Anion Dimers
Authors: Yokoyama Kenji , Maeda Shiro , Etoh Chisumi , Matsuzaki Susumu , Toyoda Koichi 
Published: July 2006

Abstract
The resonance Raman spectra of TCNE-M+ (M=Na, K, Rb, Cs) in MTHF solutions have been measured at 100 K by exciting radiations within the long wavelength absorption band characteristic of the dimer (TCNE−)2. Two remarkably resonant lines have been observed at about 180 cm−1 and 150 cm−1, showing an obvious change of the relative intensity depending on the counter cation species. The resonance behavior definitely indicates that the stretching vibration of interradical bond is responsible for these lines. Formation of two different types of dimer salts has been proposed as the most probable interpretation of the observed spectral behaviors.
On the Enhancement of the Selectivity of Organic Sulfonate Ion Electrode by Alkylphenols
Authors: Hara Hirokazu , Okazaki Satoshi , Fujinaga Taitiro 
Published: July 2006

Abstract
An enhancing effect of alkylphenols on the selectivity of the liquid membrane electrode responsive to organic sulfonate ion has been investigated. The interference of perchlorate ion expressed in terms of the selectivity coefficient decreased to one eighthundredth in the presence of p-t-octylphenol. This effect was attributed to the formation of the hydrogen bonding between the phenol and sulfonate. The dependence of the potentiometric behavior, paticularly with respect to the selectivity on the membrane components was examined. The optimum composition of the ion-exchanger for sulfonate was found to be 0.05 mol dm−3 trioctylmethylammonium p-toluenesulfonate with 0.5 mol dm−3 p-t-octylphenol in o-dichlorobenzene. The decrease of the selectivity coefficient for perchlorate due to the phenol was also discussed in relation to ion-exchange equilibrium constants, ionic parameters, and dissociation constants of the ion-pair. The effect of the membrane solvents was also discussed in terms of their solubility parameters.
Analysis of the Heat of Breaking Glass Ampoules
Authors: Morimoto Tetsuo , Kiriki Masafumi 
Published: July 2006

Abstract
The heat of breaking was measured on three series of ampoules, containing N2 at various pressures, N2 at various pressures as well as saturated H2O vapor, or different amounts of liquid H2O as well as the saturated vapor in the unfilled space, respectively. This report gives the method to analyze the heat of breaking of ampoules into three factors: the release of mechanical strain stored in the ampoule under a pressure, heat of evaporation of immersion liquid, and rush-in effect of the liquid.
The Dehydration of d-Fructose to 5-Hydroxymethyl-2-furaldehyde
Authors: Nakamura Yoshio , Morikawa Shunichi 
Published: July 2006

Abstract
The continuous dehydration of d-fructose is carried out under mild conditions, using the strongly acidic ion-exchange resin with a low divinylbenzene content as the catalyst and dimethyl sulfoxide as the solvent, to give 5-hydroxymethyl-2-furaldehyde in a high yield.
The Dynamical Behavior of the Sodium Cation in Some Crown Ether–Na+–TCNE− Ternary Complexes as Studied by ESR
Authors: Kohama Hiroyuki , Yoshinaga Mayumi , Ishizu Kazuhiko 
Published: July 2006

Abstract
ESR observations were performed for the ternary complexes formed with Na+–TCNE− and 5O-crown ethers. The temperature dependence of the observed Na hyperfine line width was analyzed by applying Bloch’s twojump model, and the thermodynamical parameters of the complex formation were determined. The stability of the ternary complexes were found to be much affected by the substitution of either the fused benzene ring or the 2,2′-biphenyldiyl group, which acts as a steric restriction during the optimum metal binding to the flexible crown ring.
Synthetic Photochemistry. XXL. The Sensitized Photooxygenation of Calarene. A Facile Hock Cleavage of an Allylhydroperoxide and Structure Revision for Aristolenols
Authors: Takeshita Hitoshi , Shimooda Isao , Hatsui Toshihide 
Published: July 2006

Abstract
An allylic hydroperoxide formed by the sensitized photooxidation of calarene causes a Hock cleavage. A revised stereochemistry of an aristolenol is given on the basis of the direction of oxygenation.
The Precipitation of Traces of Copper, Cadmium, and Lead with 6-Anilino-1,3,5-triazine-2,4-dithiol and Its Application to X-Ray Fluorescence Spectrometry
Authors: Watanabe Hiroto , Ueda Takashi 
Published: July 2006

Abstract
A selective enrichment procedure for copper, cadmium, and lead is described. This method is based on precipitating the three elements with 6-anilino-1,3,5-triazine-2,4-dithiol (ATD) or with a combination of ATD and benzyldimethyltetradecylammonium chloride (BMTAC), filtering the precipitates to form a suitable X-ray sample, and then analyzing the sample by means of X-ray fluorescence. Microgram amounts of the three elements were precipitated quantitatively with ATD from 50 cm3 or less of aqueous solutions of pH 7. Several to several tens mg amounts of such other elements as aluminium, iron(III), vanadium(V), zinc, arsenic(III, V), nickel, cobalt, and manganese(II) do not form any precipitates in the presence of citrate. Quantitative recoveries of the three elements from aqueous solutions ranging from 200 to 500 cm3 were also possible when BMTAC was present as a coagulant aid. ATD was used for the determination of the three elements in reference materials (Orchard Leaves and Pepperbush Leaves). The results agreed with the certified values and with those obtained by isotope-dilution mass-spectrometry, and the precisions were satisfactory. The three elements in hot-spring water at levels from several to several tens ppb were determined by using a combination of ATD and BMTAC.
Polarographic Trace Analysis of Cadmium(II) after Solvent Extraction Using the Salting-out Method
Authors: Fujinaga Taitiro , Nagaosa Yukio 
Published: July 2006

Abstract
A selective and sensitive method is presented for the determination of cadmium(II), based on polarography after salting-out extraction into acetonitrile. The effect of nonaqueous solvents, salting-out agents, and the concentration of reagents has been studied. Under the conditions established, the cadmium(II) iodide complex extracted into the solvent gives a well-defined d.c. wave and a sharp a.c. peak, with E1⁄2 and Ep=−0.72 V vs. SCE respectively. Down to 0.50 ppm of cadmium(II) in the original aqueous solution can be determined by the proposed method. Lead(II) and In(III) do not interfere up to a 1000-fold amount relative to Cd(II). Interference from Fe(III) and Tl(III) can be eliminated by the addition of ascorbic acid.
Mechanisms of Stannyl–Carbon Bond Cleavages by Reactions with Benzoyl Peroxide
Authors: Kozuka Seizi , Naribayashi Ikuya , Nakagami Jun-ichi , Ogino Kenji 
Published: July 2006

Abstract
The mechanism for the process giving trimethyl(benzoyloxy)stannane by the reaction of benzoyl peroxide with trimethylphenylstannane or tetramethylstannane has been investigated. The kinetic results exclude the possibility that the decomposition of the peroxide is induced by the stannanes. The addition of dicyclohexylcarbodiimide as a trapping agent for benzoic acid markedly depressed the yield of the benzoyloxystannane by the reaction of trimethylphenylstannane, suggesting that the benzoyloxystannane is mainly or exclusively produced by the protodestannylation reaction of trimethylphenylstannane with benzoic acid. In the reaction of tetramethylstannane with benzoyl peroxide, trimethyl(benzoyloxy)stannane was formed only when a large excess of the stannane was used, and dicyclohexylcarbodiimide showed no significant effect upon the formation of the benzoyloxystannane. A homolytic process has been suggested for the reaction giving the benzoyloxystannane from tetramethylstannane.
Reactions of α-Aminoacetonitriles with Isothiocyanates. Synthesis of 1,3-Disubstituted 5-Imino-2-thiohydantoins
Authors: Kinoshita Takeshi , Watanabe Hiroko , Sato Sadao , Tamura Chihiro 
Published: July 2006

Abstract
The reactions of α-aminoacetonitriles with isothiocyanates gave 1-cyanomethyl-1,3-disubstituted thioureas or 1,3-disubstituted 4-amino-4-imidazoline-2-thiones depending upon the reaction conditions. In the presence of polar organic solvents such as methanol the former products were easily cyclized to the latter. 1,3-Disubstituted 4-amino-4-imidazoline-2-thiones were autoxidized in methanol affording 1,3-disubstituted 5-imino-2-thiohydantoins.
Adsorption of n-Aliphatic Alcohols on Mercury Electrode and Their Effect on Electrode Kinetics
Authors: Niki Katsumi , Takizawa Yumiko 
Published: July 2006

Abstract
The adsorption parameters of butyl alcohol, amyl alcohol, and hexyl alcohol at mercury electrode were evaluated by means of the electrocapillary measurements and compared with those obtained by differential capacity measurements. A marked difference is observed both in the interaction parameters between adsorbed molecules and in the maximum surface excess, Γmax. The inhibition effect by these alcohols on the electrode kinetics of the vanadium(III)/vanadium(II) couple in 0.5 M H2SO4 and of the europium(III)/europium(II) couple in 1.0 M HCl depends only on the surface coverage, θ=Γ⁄Γmax, of the electrode and is independent of the chain length of the adsorbed alcohol. The blocking effect is predominant in the inhibition of the electrode process by these alcohols.
A Novel System Consisting of a Soluble Inorganic Reagent Caged in the Network Structure of Gels
Authors: Matsumoto Yoshio , Shirai Michiko , Kawashima Takeshi 
Published: July 2006

Abstract
A new type of system was prepared which consisted of a water-soluble macromolecular metal complex caged in the network structure of a gel particle, the caged reagent being soluble in nature in an aqueous solution, but unable to get out of the gel particle into the outside solution by going through the network because of its large molecular size. This system was further proved to be useful as a convenient capturer of heavy metal ions in an aqueous solution.
Microscopic Evaluation of Surfactant–Water Interaction in Apolar Media
Authors: Sunamoto Junzo , Hamada Tomiko , Seto Takafumi , Yamamoto Shinji 
Published: July 2006

Abstract
Under the very limited conditions where the mole ratio of water to surfactant is about unity or so, the tightness of the interaction between various ionic surfactants and water solubilized in apolar media was evaluated using the O–H vibrational mode of water in the near infrared spectral region. Water solubilized in apolar solvents containing surfactant exhibited two absorption bands in the region. One of the two arises from water existing in bulk organic phase and appears around 1900–1910 nm. Another band arises from water bound to surfactant and appears over a range of 1920–2020 nm; it is affected primarily by the ionic head group of surfactant rather than by the counter ion. The cationic surfactants were thought to form more rigid micelles than the zwitterionic or anionic ones. The copper (II) ion cosolubilized in the system hardly altered the O–H vibrational energy of water. The dependence of the near infrared absorption band on water, the chemical shift and line width of water proton resonance in NMR, and the fluorescence intensity of terbium chloride all displayed an inflection at the point where the mole ratio of water to surfactant is about unity. This was interpreted in terms of the two step hydration mechanism.
Reflection Spectrum of the Single Crystal of Wurster’s Blue Perchlorate
Authors: Iyechika Yasushi , Yakushi Kyuya , Kuroda Haruo 
Published: July 2006

Abstract
The visible and near-infrared reflection spectrum of the single crystal of Wurster’s blue perchlorate was measured at various temperatures over the range of 30–300 K, by using the microspectrophotometric method. The absorption spectra were derived by Kramers-Kronig transformation of the reflection spectra. The intensity ratio of the (0-0) and (0-1) vibronic bands of the local-excitation associated with the π-π* (2B1u←2B2g) transition of TMPD+ was found to be anomalous when the spectrum was measured with the light polarized parallel to the b-axis, while not in the spectrum polarized parallel to the a-axis. The Davydov splitting between B3u and B2u components of this absorption band was found to be about 400 cm−1. In the antiferromagnetic (low temperature) phase below 190 K, the charge-transfer band appeared in the a-axis spectrum, showing its absorption maximum at 11.6×103 cm−1, and its intensity increased on lowering the temperature. At the same time, a marked temperature dependence was observed in the local-excitation band. These changes are interpreted in terms of the singlet-triplet model of the dimeric interaction of TMPD+ ions in the low-temperature phase.
Electrophoresis and Diffusion Studies of the Solubilization of Polar and Nonpolar Oily Compounds with Sodium Dodecyl Sulfate. II
Authors: Ogino Keizo , Takeshita Nobuo 
Published: July 2006

Abstract
The solubilization of polar and nonpolar oily materials into an aqueous sodium dodecyl sulfate (SDS) solution with and without sodium chloride was studied. Normal paraffins and their derivatives, with carbon numbers of C7, C8, and C10, were used as solubilizates, the extents of solubilization, the relative viscosities of the solutions, the diffusion coefficients, and the electrophoretic mobilities of the micelles in the solutions were observed, and the effective specific volumes, the effective radii, the ζ-potentials, and the effective charge of the micelles were derived assuming that the micelles were spherical. The micelles of SDS showed increasing mobilities when they incorporated octanoic acid, 1-octanol, and decanoic acid, while the mobilities decreased when they incorporated heptane, octane and 1-decanol. On the basis of these results, we discussed the mechanism of the solubilization of polar and nonpolar oily compounds with SDS.