bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi-ionic Potential and Membrane Permeability Matrix. I. NaCl–CsCl Bi-ionic System with a Cation Exchange Membrane
Authors: Kaibara Kozue , Kimizuka Hideo 
Published: July 2006

Abstract
This paper is concerned with analysis of membrane transport processes on the basis of nonequilibrium thermodynamics. Inter-ionic correlations between permeating ions are quantitatively estimated by applying the membrane permeability matrix theory to the system in which the NaCl and CsCl solution phases are divided by a highly selective cation exchange membrane. The membrane permeability matrix of the system may be expressed by four ionic correlation terms concerning with Na+ and Cs+. The electroconductive and diffusional membrane permeabilities are expressed as a function of the matrix elements having the dimension of permeating speed of ions. The conductive and diffusional permeabilities as well as the matrix elements are estimated from membrane potential, conductance, and ionic flux data. The external electrolyte concentration dependence of these permeability parameters is discussed. The conductive and diffusional permeabilities considerably differ from each other and their ratio changes with the external electrolyte concentration, whereas the permeability ratio of Na+ to Cs+ is constant. Electroconductive and diffusional characteristics of membrane transport processes are consistently analyzed in terms of the memberane permeability matrix theory.
Kinetic Studies of Spin Trapping Reactions. III. Rate Constants for Spin Trapping of the Cyclohexyl Radical
Authors: Doba Takahisa , Yoshida Hiroshi 
Published: July 2006

Abstract
In order to give a quantitative basis for the spin trapping technique, the spin trapping rate constants for the reactions between commonly-used spin traps and cyclohexyl radicals have been determined. The cyclohexyl radicals were generated by γ-irradiating cyclohexane solutions of the spin traps. The rate constants for nitrosobenzene, nitrosodurene, pentamethylnitrosobenzene, 2,4,6-tri-t-butylnitrosobenzene, and α-phenyl-N-t-butylnitrone at 299 K are 9×107, 1.4×107, 1.6×107, 2.4×104, and 8×103 mol−1 dm3 s−1, respectively. The results are qualitatively in accordance with previous data for t-butyl, 1-methyl-5-hexenyl radicals.
The Estimation of the Liquid-Liquid Distribution Coefficients of Acetylacetone by Means of the Group Solution Theory
Authors: Kato Masanao 
Published: July 2006

Abstract
The estimation of the liquid-liquid distribution coefficients of acetylacetone tautomers was attempted on the basis of the UNIFAC equation, and it was found that the calculated values of the reciprocals of the activity coefficients of tautomers in organic phases were linearly related to the distribution coefficients. It was verified that the estimation by the UNIFAC equation could be extended to the organic solvents with no characteristic parameter.
Electron Spin Resonance and Some Spectral Studies on Coordination Behaviors of Paramagnetic Metal Ions for Chelating Resins
Authors: Nakashima Akira , Isobe Toshiyuki , Tarutani Toshikazu 
Published: July 2006

Abstract
Coordination behaviors of VO(II), Cr(III), Mn(II), Fe(III), Cu(II), and Gd(III) ions for the iminodiacetato group in the chelating ion-exchange resin Dowex A-1 were studied with the aid of ESR, infrared absorption, and M\ddotossbauer spectroscopies. A comparative investigation also was made with the o-hydroxybenzyliminodiacetato group in the chelating resin Unicellex UR-50. The iminodiacetato group in Dowex A-1 is considered to coordinate as a tridentate ligand and form 1 : 1 chelates with metal ions, whereas the o-hydroxybenzyliminodiacetato group in Unicellex UR-50 coordinates as a quadridentate ligand in alkaline media and forms 1 : 1 chelates. Elucidation of spin-spin exchange interaction has led to a conclusion that the iminodiacetato groups present in the coordination pore of Unicellex UR-50 are closer to one another than those of Dowex A-1. For Fe(III) ions adsorbed in concentrated HCl media, besides the species [FeCl4]−, lower symmetric species are considered to be adsorbed with the anion exchange effect, from results of resin phase ESR and Mössbauer spectra.
The Crystal and Molecular Structure of (N-Benzyl-l-alaninato)[N,N′-ethylenebis(α-methylsalicylideneaminato)]cobalt(III) Trihydrate
Authors: Kushi Yoshihiko , Tada Toshiji , Fujii Yuki , Yoneda Hayami 
Published: July 2006

Abstract
The crystal and molecular structure of the title complex (−)435-ΛRS-β2(mer)-[Co(α-Me-sal2en)(N-Bz-l-ala)]·3H2O, has been determined by single crystal X-ray analysis. The crystals are orthorhombic, space group P212121, with unit cell dimensions a=19.247(8), b=14.162(4), c=10.329(4) Å, and Z=4. The structure was solved by the heavy-atom method and refined by block-diagonal least-squares technique, using 1624 independent reflections, to the final R-value of 0.080. The molecular structure is of a ΛRS-cis-β2(mer) type in which two coordination sites of a distorted octahedron are occupied by the N-Bz-l-ala group and the others by the quadridentate α-Mesal2en Schiff-base ligand in a nonplanar configuration. The Co–O and Co–N bon lengths, 1.938(12) and 1.989(15) Å respectively, of the N-Bz-l-ala group are significantly longer than the usual values. The molecule is distinctly strained as shown by the bond angles of the ligands and those of the cobalt(III) coordination polyhedron. The water molecules form a hydrogen bonded chain linking phenolate and carboxylate oxygens of different molecules along the crystallographic c axis.
Potentiometric Study of Thermodynamic Parameters of Complexing of Lithium Ion–Basic Aprotic Solvents and Sodium Ion–Macrocyclic Polyethers in Acetonitrile
Authors: Nakamura Toshio , Yumoto Yasuke , Izutsu Kosuke 
Published: July 2006

Abstract
Formation constants of the 1 : 1 complexes of lithium ion in acetonitrile (AN) with DMF, DMSO, DMA, and HMPA and of sodium ion in AN with 15-crown-5 (15C5), 18-crown-6 (18C6), dibenzo-18-crown-6 (DB18C6), and cryptand 211 (Cryp 211), were determined at 10, 25, and 40 °C by potentiometric methods with a cationsensitive glass electrode. From the change of the formation constants with temperature, thermodynamic parameters ΔG298°, ΔH298° and −TΔS298°, were obtained. ΔG298°, ΔH298°, and −TΔS298° all in kJ mol−1, for Li+-solvent complexes were, respectively, −7.9, −9·0, +1·1 for DMF, −9.7, −10·1, +0·5 for DMSO, −10.0, −9·9, −0·1 for DMA, and −18.9, −15·8, −3·1 for HMPA, and those for Na+-macrocyclic polyether complexes, −28.4, −24·1, −4·5 for 15C5, −27.2, +1·6, −28·7 for 18C6, −28.6, −14·3, −14·2 for DB18C6, and −51.9, −53·8, +2·1 for Cryp 211. Some features about the roles of enthalpy and entropy terms in complexing have been discussed.
The Flow-injection Analysis of d-Glucose Using a Flow-cell with Immobilized Peroxidase and Its Application to Serum
Authors: Hara Tadashi , Toriyama Motohiro , Imaki Masakatsu 
Published: July 2006

Abstract
The d-glucose concentration in a serum sample of less than 0.01 cm3 could be continuously determined at the rate of about 20 samples/h by the use of a chemiluminescent reaction between luminol and hydrogen peroxide, a flow-cell with immobilized peroxidase, and a column with immobilized glucose oxidase. By immobilizing peroxidase as a chemiluminescent catalyst inside the flow-cell, simplification could be achieved with regard to apparatus, reagents and operation. The detection limit of hydrogen peroxide was about 5×10−6 mol dm−3, and the calibration curves for both hydrogen peroxide and d-glucose were approximately linear in the range of 5×10−5–1×10−3 mol dm−3, a range which corresponded to the glucose concentration, 0.1–18 mg cm−3, obtained by diluting serum to 50 times its initial volume.
A Calorimetric Study on the Relative Thermal Stability in Some Nickel(II) Complexes Containing N,N′- or N,N-Diethylethylenediamine
Authors: Tsuchiya Ryokichi , Uehara Akira , Ohtsuka Yoshiyuki 
Published: July 2006

Abstract
The enthalpy changes (ΔH) in the reaction of Ni(AA)2X2·nH2O type complexes with aqueous potassium cyanide were calorimetrically measured at 25 °C, where AA is N,N′-diethylethylenediamine (NN′-deen) or N,N-diethylethylenediamine (NN-deen); X is Cl−, Br−, I−, or NO3− ion; and n is 0 or 2. On the basis of the enthalpy data measured, the thermal stability was compared among chloride, bromide, iodide, and nitrate in the following each group of compounds: Ni(NN′-deen)2X2·2H2O, Ni(NN′-deen)2X2, Ni(NN-deen)2X2·2H2O, and Ni(NN-deen)2X2. The thermal stability was found to decrease in the order, chloride&gt;bromide&gt;nitrate&gt;iodide in each group. Comparison of the enthalpy data between the chlorides of the NN′-deen and NN-deen complexes revealed the difficulty of anation in the latter rather than in the former. [Ni(NN-deen)2(H2O)2]Br2 was, when heated, converted into [Ni(NN-deen)2]Br2 without anation differing from the chloride. The difference was also discussed on the basis of the enthalpy data.
Orbital Tilting Due to Destabilizing Four-electron and Stabilizing Two-electron Orbital Interactions. An Elucidation of Exo-endo-nonequivalency of π-MO Extension of Norbornene
Authors: Ito Suketaka , Kakehi Akikazu 
Published: July 2006

Abstract
A new concept, “Orbital Tilting,” leading to hybridization change, was introduced on the basis of the destabilizing and the stabilizing secondary orbital interaction. The predominant π-MO extension of norbornene in the exo-direction was elucidated by application of the concept to the orbital system.
Photoreduction of Aminoanthraquinones by an Electron Transfer via the Upper Excited nπ* Triplet State
Authors: Inoue Haruo , Kawabe Kiyoshi , Kitamura Noboru , Hida Mitsuhiko 
Published: July 2006

Abstract
The photoreduction of 2-piperidinoanthraquinone (1) by an electron transfer from hydroxide ion in aqueous 2-propanol was reinvestigated. The reaction proceeded actively on irradiation at 365 nm, but very weakly on irradiation at 420 nm. The fluorescence of 1 was not affected by hydroxide ion. 1,3-Cyclohexadiene as a triplet quencher retarded the photoreduction. All results revealed that the reactive state of 1 in the photoreduction is not the intramolecular excited CT state, but the upper excited nπ* triplet state. Kinetic studies indicated that the rate of deactivation from the T2(3nπ*) level of 1 is unusually slow (kd=1.7×108 s−1). The photoreduction via the upper excited T2(3nπ*) level was also observed in 1-amino- and 1-piperidinoanthraquinone, while 2-aminoanthraquinone did not exhibit any reactivity. Wavelength-dependencies (313 nm, 365 nm, and &gt;420 nm irradiations) of the photoreductions were also observed.
Interaction of Amylose with Iodine. I. Characterization of Cooperative Binding Isotherms for Amyloses
Authors: Yamamoto Masako , Sano Takayuki , Yasunaga Tatsuya 
Published: July 2006

Abstract
The interaction of amylose with iodine was investigated as a function of degree of polymerization (DP) of amylose by amperometric titration, and the binding isotherms were obtained. The intrinsic equilibrium constant and cooperative parameter were determined with a one-dimensional Ising model for amyloses of various DPs. The inflection of the plot of the intrinsic equilibrium constant vs. DP observed at about DP 60 suggests that a helical segment of amylose consists of anhydroglucose residues less than 60. The discontinuity of the cooperativity at about DP 60 was interpreted by two kinds of cooperative effects, intra- and interhelical effects. These results suggest that the interrupted helix is a good model for the amylose structure in aqueous solution. The temperature dependencies of the cooperative parameters show that the cooperativity of amylose-iodine complexation is entropycontrolled.
The Determination of the Ratio of Two Kinds of Hydrogen in Metal Hydrides by Means of Pulsed NMR
Authors: Hayashi Shigenobu , Hayamizu Kikuko , Yamamoto Osamu 
Published: July 2006

Abstract
A method is proposed by which the composition of the two kinds of hydrogen with different diffusional behavior in metal hydrides can be determined accurately by means of 1H NMR; using the method, it is found that the energy difference between the two sites occupied by the two kinds of hydrogen is 7.9 kJ/mol in VH0.77.
Reduction by a Model of NAD(P)H. 36. First and Direct Evidence for the Multi-step Mechanism
Authors: Yasui Shinro , Nakamura Kaoru , Ohno Atsuyoshi , Oka Shinzaburo 
Published: July 2006

Abstract
Reductions of thiobenzophenone derivatives with a model compound of NAD(P)H, 1-benzyl-1,4-dihydronicotinamide (BNAH) or N-(α-methylbenzyl)-1-propyl-2,4-dimethyl-1,4-dihydronicotinamide (Me2PNPH), in a solvent containing an O-deuterated alcohol afforded products partially deuterated at their methine positions. The deuterium content depends both on the character of substituents in the substrate and on the polarity of solvent. In contrast, no incorporation of deuterium into the product was observed in the reduction of thiopivalophenone with BNAH or Me2PNPH under the same conditions. These results can be accounted for in terms of an electron transfer followed by a proton transfer from the model to substrate. This is the first and direct evidence for the ion radical-pair intermediacy for reductions by model compounds of NAD(P)H.
Effect of Molecular Size on the Association of p-Quinone Anion and Lithium Ion in N,N-Dimethylformamide
Authors: Nagaoka Tsutomu , Okazaki Satoshi , Fujinaga Taitiro 
Published: July 2006

Abstract
Ion pair formation effects of metal ions on the electro-reduction of p-quinones in N,N-dimethylformamide were studied systematically by polarography. The formation constants of 1 : 1 and 1 : 2 associates, as evaluated by the 1/F02-weighted least squares method, decrease with increase in the anion size.
Synthesis and Lithiation of 2-Alkylthio- and 2-Arylthio-1,3-dithiolanes
Authors: Tanimoto Shigeo , Oida Tatsuo , Ikehira Hideyuki , Okano Masaya 
Published: July 2006

Abstract
Several 2-alkylthio- and 2-arylthio-1,3-dithiolanes were synthesized by the reaction of 2-ethoxy-1,3-dithiolane with aliphatic and aromatic thiols in the presence of ZnCl2. The lithiation of 2-alkylthio-1,3-dithiolanes with butyllithium in tetrahydrofuran followed by the addition of alkyl halides gave unsymmetrical dialkyl trithiocarbonates in moderately good yields.
The Synthesis and Electrical Resistivities of Complexes of Cation–TCNQ–Salts with Crown Ethers, Cryptands, and 1,13-Di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane
Authors: Matsuoka Katsumi , Nogami Takashi , Matsumoto Tsuruyoshi , Tanaka Hidekazu , Mikawa Hiroshi 
Published: July 2006

Abstract
Cation–TCNQ complexes with crown ethers, cryptands, and 1,13-di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane were isolated. The cations include alkali-metal, and alkyl- and arylammonium ions. Nine types of complexes were isolated. These complexes are classified into two groups: complexes containing neutral TCNQ, and the complexes not containing neutral TCNQ. The electrical resistivities of the compaction samples were mainly measured at room temperature. The complexes containing neutral TCNQ were much more conductive than the other type of complexes; they exhibit resistivities of 8.2–103 Ω cm. The complexes of 1,13-di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane contained methanol when we synthesized them from methanol solution.
Photoelectrochemical Reduction of Carbon Dioxide at p-Type Gallium Phosphide Electrodes in the Presence of Crown Ether
Authors: Taniguchi Yasuhiko , Yoneyama Hiroshi , Tamura Hideo 
Published: July 2006

Abstract
Reduction of carbon dioxide at p-type GaP photocathodes was investigated in lithium carbonate electrolytes. The reduction occurs in competition with hydrogen evolution and its current efficiency is enhanced by dissolving crown ether such as 15-crown-5 in the electrolyte. It is proposed that a chemical reaction pathway is involved in which the reduction of carbon dioxide is initiated by cathodically deposited lithium with formation of the anion radical of carbon dioxide.
Phosphinyl- and Phosphinothioylamino Acids and Peptides. VI. The Protection of the Hydroxyl Function in the Tyrosine Side-chain by the Dimethylphosphinothioyl Group
Authors: Ueki Masaaki , Inazu Toshiyuki 
Published: July 2006

Abstract
The use of the dimethylphosphinothioyl(Mpt) group for the protection of the hydroxyl function in the tyrosine side-chain was studied. N,O-Bis(Mpt)tyrosine was obtained directly by a Schotten-Baumann-type reaction of Mpt–Cl with tyrosine. The O-Mpt group was stable under acidic conditions, and it could be removed easily by alkaline hydrolysis or ester-exchange reaction. The usefulness of this new protecting group for the peptide synthesis was shown in the solid-phase synthesis of [d-Ala2, l-Leu5]-enkephalin(H–l-Tyr–d-Ala–Gly–l-Phe–l-Leu–OH) and its N-allyl derivative.
The Crystal and Molecular Structure of Cu(AlCl4)2
Authors: Kitajima Nobumasa , Shimanouchi Hirotaka , Ono Yoshio , Sasada Yoshio 
Published: July 2006

Abstract
The structure of copper(II) tetrachloroaluminum Cu(AlCl4)2 was determined by the single-crystal X-ray diffraction technique. The crystal is triclinic: a=6.582(6), b=7.362(5), and c=12.265(5) Å; α=89.99(5), β=85.97(6), and γ=89.77°; space group P\bar1 and Z=2. The structure was solved by the heavy-atom method and refined by applying the block-diagonal matrix least-squares technique on 2628 independent reflections up to a final R value of 0.110. The structure consists of closely-packed centrosymmetric Cu(AlCl4)2 molecules with copper atoms tetragonally coordinated. Structural difference between Cu(AlCl4)2 and Co(AlCl4)2 is described.
Circular Dichroism Spectra of fac(D)-[Co(a)(BC)(DDD)n+ Type Complexes with 1,4,7-Triazacyclononane, (2R)-2-Methyl-1,4,7-triazacyclononane, and 1,5,9-Triazacyclododecane
Authors: Fujinami Shuhei , Matsunami Yukio , Shibata Muraji 
Published: July 2006

Abstract
The complexes, [Co(l-val)(NH3)(tacn)]2+ (tacn=1,4,7-triazacyclononane), [Co(gly)(NH3)(Me-tacn)]2+ (Me-tacn=(2R)-2-methyl-1,4,7-triazacyclononane) have been prepared and separated into diastereomers by column chromatography. Six other complexes, [Co(a)(β-ala)(tacn)]n+ (a=CN−, NO2−, or NH3) and [Co(a)(gly)(tacdd)]n+ (a=NO2−, NCS−, or H2O; tacdd=1,5,9-triazacyclododecane) have also been prepared and resolved into enantiomers. By comparing the CD spectra of the l-valinato and the Me-tacn complexes with that of [Co(gly)(NH3)(tacn)]2+, the optical activities of [Co(a)(gly)(tacn)]+ are considered to be mainly derived from chiral arrangements of four kinds of donor atoms. The change from five-membered chelate ring to a six-membered one has slight influence upon the CD spectral shapes in the β-alaninato complex, but a large influence in the tacdd complexes.
Ion-pair Extraction of Nickel(II) and Copper(II) Complexes of 8-Hydroxy-7-nitroso-5-quinolinesulfonic Acid with Zephiramine
Authors: Ozaki Toyoko 
Published: July 2006

Abstract
The ion-pair extraction of nickel(II) and copper(II) complexes of 8-hydroxy-7-nitroso-5-quinolinesulfonic acid (H2NQS) with zephiramine(benzyldimethyltetradecylammonium chloride) was studied. It was found that slope analysis can be used to determine the mechanism of these ion-pair extraction systems, as well as the continuous-variation method for three component systems or the mole-ratio method by choosing appropriate extraction conditions. As a result, the equation of these extraction equilibria can be represented as:
M2++2HNQS−+2ZCl(o)\ightleftharpoonsM(NQS)2Z2(o)+2Cl−
The extraction constants and the exchange constants were calculated.
Pyrolytic Sulfurization Gas Chromatography. XI. An Improved Apparatus and Procedure for Practical Use
Authors: Hara Tadashi , Okui Fujio 
Published: July 2006

Abstract
With the objectives of reducing the time necessary for an analysis and of improving the precision and accuracy of the analysis value, the isothermal gas-chromatographic optimum conditions were investigated and established. By the present method, the time necessary for an analysis is reduced to 25 min, from 35 min under the previous conditions, and both precision and accuracy are further improved together with an improvement of the calculation method of the calculation factors used in the calculation of the atomic ratio between C, H, O, and N. Thus many standard samples, including some liquid ones which are newly examined in this study, can be analyzed within an absolute error of about ±0.2%.
Kinetics and Mechanism of Decompositions of N-Methyl-N′-aryl-N-nitrosoureas and Related Compounds in Aqueous Buffer Solution
Authors: Yoshida Kitaro , Yano Kazuyuki 
Published: July 2006

Abstract
The decomposition reactions of N-methyl-N′-aryl-N-nitrosoureas (1) and of N,N′-dimethyl-N′-aryl-N-nitrosoureas (2) were studied kinetically in phosphate buffer solution. All nitrosoureas 1 were easily hydrolyzed even under neutral conditions and the rates of hydrolysis were found to be proportional to the hydroxide ion concentration over pH range 5.4–7.6. General base catalysis by buffer components was negligible. The reaction was subjected to the elimination mechanism in which an abstraction of the ureido proton was involved as an initial step. On the other hand, nitrosoureas 2 had no significant reactivity under the same conditions.
Bis(2,4-pentanedionato)phenylchromium(III). Preparation and Reactions with Organic Carbonyl Compounds and Alcohols
Authors: Ito Takashi , Ono Tsukasa , Maruyama Kazunori , Yamamoto Akio 
Published: July 2006

Abstract
A phenylchromium complex CrPh(acac)2 (1) (acac=2,4-pentanedionato ligand) was prepared from Cr(acac)3 and AlPh3·Et2O. Complex 1 reacts with acetone to give benzene, 2-phenyl-2-propanol, and mesityl oxide and is converted into a hydroxo complex [Cr(OH)(acac)2]2. The mechanism involving the insertion of the carbonyl group of acetone into the Ph–Cr bond giving an alkoxo intermediate is proposed. Reactions of 1 with esters proceed similarly to give diphenylmethanol derivatives and alkoxochromium complexes. Complex 1 reacts with ROH to give benzene and alkoxo complexes [Cr(OR)(acac)2]n [n=1 or 2) which were characterized by means of IR spectra, elemental analyses, molecular weight measurements, magnetic susceptibilities, and chemical reactions. The reactions of 1 with β-dicarbonyl compounds yield corresponding mixed chelate complexes Cr(β-dic)(acac)2, where β-dic=diethyl malonato and 1-ethoxy-1,3-butanedionato ligands.
The Crystal and Molecular Structure of 1-(2-Amino-4-pyrimidinyl)-β-carboline
Authors: Yokomori Yoshinobu , Sekido Kiyotane , Wu Tian-Shung , Tien Hsien-Jun , Hirokawa Sakutaro 
Published: July 2006

Abstract
An alkaloid extracted from a small evergreen tree, Annona montata, was identified as 1-(2-amino-4-pyrimidinyl)-β-carboline monohydrate by the X-ray method. The crystal data are; a=20.699, b=4.453, c=15.720 Å, and β=112.16°; space group, P21/c; Z=4. The structure was solved by the direct method and refined by the least-squares method to the final R value of 0.109 for 1451 independent reflections. The water molecule is connected to four nitrogen atoms by hydrogen bonds. Two of them are in different groups; one is in the five-membered ring of the β-carboline skelton, and the other is in the pyridine of the β-carboline skelton. The fifth hydrogen bond connects two nitrogen atoms, one of which is in the amino group, and the other, in the pyrimidine skelton.
Salt Effects on the Intramolecular Cannizzaro Reaction of Phenylglyoxal. Specific Acceleration by Calcium Ion
Authors: Okuyama Tadashi , Kimura Kazumasa , Fueno Takayuki 
Published: July 2006

Abstract
Effects of added salts on the rate of alkaline rearrangement of phenylglyoxal to mandelic acid were examined in aqueous solution at 30 °C. The reaction showed positive salt effects. Specific acceleration was found with some metal ions, the efficiency decreasing in the order Ca2+&gt;Tl+&gt;Sr2+&gt;Ba2+.