bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of Ion-exchange on Sodium-, Calcium-, and Magnesium Saturated Kaolinites
Authors: Bansal Om Prakash
Published: July 2006

The kinetics of Na+, Ca2+, Mg2+, and Ni2+ ion-exchange reactions on kaolinite have been studied at four temperatures 16, 26, 36, and 46 °C. The mechanism of ion-exchange is a film diffusion as shown by interruption and φ tests. Kinetics parameters e.g. diffusion coefficients, half time of exchange, energies of activation have also been calculated and were used to predict the theoretical behaviour (mechanism) of Ni2+ exchange on the kaolinite surface.
Studies on Synthetic Inorganic Ion Exchangers. VI. Synthesis and Characterization of Iron(III) Molybdate as an Ion Exchanger
Authors: Thind Pritam Singh , Singh Harbans , Parveen (Miss)
Published: July 2006

Six preparations of iron(III) molybdate were obtained at various pH values under different conditions. They all possess cation exchange properties. The preparation, obtained by reaction of iron(III) nitrate with ammonium molybdate at pH 1 with 24 h refluxing, is the stablest and has an ion exchange capacity of 1.39 mequiv. g−1. The mole ratio of Fe: Mo is 1:3. Distribution coefficients for many metal ions were determined on this preparation. On the basis of pH titrations, chemical and thermal analyses, and infrared and Mössbauer spectra, a tentative structure of iron(III) molybdate is proposed.
The Crystal and Molecular Structure of 3,4-Dichloronitrobenzene
Authors: Kumakura Shigekazu , Kuroishi Yoshinobu
Published: July 2006

C6H3Cl2NO2, F. W.=192.0, tetragonal, I41/a, a=28.094(12), c=3.838(6) Å, V=3030 Å3, Z=16, Dx=1.68 Mg m−3, μ(Mo Kα)=0.8 mm−1. Refinement with 1093 diffractometer data gave a final R value of 0.07. The molecule is practically planar except for the nitro group, the plane of which is inclined at 8.8° to the benzene plane. The two C–Cl bond distances are approximately equal to each other. The intermolecular Cl(2)···O(2ii) contact of 3.095 Å is remarkably short.
The Reaction of Organoboranes with Lithium Salts of Trisylhydrazones of Cycloalkanones Followed by Treatment with Iodine
Authors: Baba Tsutomu , Avasthi Kamlakar , Suzuki Akira
Published: July 2006

The titled reaction proceeds smoothly under mild conditions to give corresponding 1-alkylcycloalkenes in excellent yields. The overall reaction provides a convenient synthetic procedure of cycloalkenes for cycloalkanones, with various alkyl substituents readily available by means of hydrobortation.
The Crystal and Molecular Structure of Daphnin Dihydrate: 7-(β-d-Glucopyranosyloxy)-8-hydroxycoumarin Dihydrate
Authors: Ueno Katsuhiko , Sato Mitsuhiko , Saito Norio
Published: July 2006

The title compound, C15H16O9·2H2O, crystallizes in orthorhombic space group P212121 with a=7.082(2), b=34.789(5), c=6.867(2) Å, and Z=4. The structure was solved by direct method and refined by least-squares to a final R of 0.038 based on 1841 observed reflections measured on a four-circle diffractometer. The coumarin ring is approximately planar and the torsion angle around the glucosidic C–O bond is 13.5°; this is much smaller than the corresponding value in 8-glucosyloxy-7-hydroxycoumarin, and causes considerable intramolecular repulsion around the glucosidic linkage. The valence angle of the oxygen atom linking the coumarin and glucose moieties is quite large, 118.5°. The glucopyranose portion is in a C1 chair conformation. Glucosidation at the 7-hydroxyl group brings about considerable decrease of the resonance system of the 7-hydroxylated coumarin moiety. Such an effect seems to play an important role in the transglucosidation of dihydroxycoumarin glucosides.
Kinetics of Valinomycin- and Tetranactin-mediated Cation Transport through Liposomal Membrane
Authors: Ueno Masaharu , Yasui Tomomi , Horikoshi Isamu
Published: July 2006

Kinetics of valinomycin- and tetranactin-mediated cation transport were studied. An equation was derived which describes the kinetics of ionophore induced cation leakage from liposomes. The theoretically predicted ion-selectivity of the ionophore-mediated cation transport agreed well with that given by experiments. This supports the assumptions used in the derivation and is consistent with the following characteristics of the ionophores: (1) Ionophore-mediated cation transport is carried out by stoichiometrically forming a ternary complex between ionophore, cation and lipophilic anion. (2) The ion-selectivity of the ionophore is determined primarily by the formation constant of the ionophore cation complex in water. (3) A relative value of the complex formation constant in water can be calculated from both the complex formation constant in methanol, which is estimated more easily than that in water, and the difference between desolvation energy of the cation in water and methanol.
Coenzyme Models. 34. Synthesis and Oxidation Ability of a Metal-coordinative Flavin
Authors: Shinkai Seiji , Ishikawa Yuichi , Manabe Osamu
Published: July 2006

A new metal-coordinative flavin(2,4,7-trimethylquino[8,7-g]pteridine-9,11(7H,10H)-dione: (1)) which has a phenanthroline-like skeleton within the molecular structure was synthesized. Being different from conventinal flavins, the new flavin showed a significant affinity toward metal ions and the absorption spectra were sensitively affected by added metal ions. The spectral patterns were classified into three types, which were assigned respectively to the different coordination structures. It was demonstrated through oxidation of dihydropyridine derivatives, phenylhydrazine, and l-ascorbic acid that complexed metal ions are able to “activate” 1 as oxidizing agent. The complexes with Zr4+ and Fe3+ even oxidized alcohols at ambient temperature. Unexpectedly, it was found that tetrahedral coordination metals such as Cd2+, Zn2+, and Co2+ frequently give the stable semiquinone radical of 1. The remarkable stabilization effect of these metals was attributed to a bent, butterflywing structure of the semiquinone radical. These findings suggest that the 1–metal complexes are useful not only as a model system of metalloflavoproteins but also as an in vitro oxidation catalyst.
Photoresponsive Crown Ethers. 9. Cylindrical and Phane Crown Ethers with Azobenzene Segments as a Light-switch Functional Group
Authors: Shinkai Seiji , Honda Yoshihiro , Minami Takahide , Ueda Kaori , Manabe Osamu , Tashiro Masashi
Published: July 2006

Cylindrical and phane crown ethers with azobenzene segments as a light-switch functional group were synthesized. Cylindrical ionophores in which two diazacrown ethers are linked by two photoresponsive azobenzene pillars change their binding ability for polymethylenediammonium salts in response to photoirradiation. Thus, the distance between the two crown rings can be photocontrolled. A phane-type ionophore in which 1,23-bis(p-aminophenoxy)-3,6,9,12,15,18,21-heptaoxatricosane is linked by a trans-4,4′-azobenzenedicarbonyl segment exhibits no affinity with all alkali metal cations but significantly binds Rb+ and Cs+ under UV-light irradiation. This is the example of the “all-or-nothing” control of the ion-binding ability and implies that a crown-like loop emerges only when the azobenzene segment is photoisomerized to the cis-configuration. These ionophores are categorized to novel photoresponsive crown ethers.
The Interaction of a Neutral Polymer with Small Ions in Solution. III. Ionic Association on a Poly(oxyethylene) Chain
Authors: Awano Hiroshi , Ono Katsumichi , Murakami Kenkichi
Published: July 2006

Conductivities of NaSCN and KSCN solutions have been measured in ethanol and nitromethane in the presence of poly(oxyethylene). For poly(oxyethylene)–KSCN solutions in ethanol and nitromethane, a distinct minimum appears in conductivity vs. polymer concentration curves. In addition, for a poly(oxyethylene)–NaSCN solution in nitromethane, the conductivity curve rises steeply after passing through the minimum. These anomalies cannot be explained by the cation binding to the polymer alone, and the ionic association on the polymer chain should be taken into account at the same time. In order to analyze the results, a theory based on the duplicate ion binding on a one-dimensional lattice has been developed. The theory not only predicts the appearance of the conductivity minima, but also makes it possible to estimate the ionic association constants.
Anomalous Near Infrared Emission Observed in High Energy Electron Excited Xe and Xe–Ar
Authors: Tanaka Masako , Sasaki Susumu , Katayama Meiseki
Published: July 2006

The near infrared emission spectra of Xe and Xe–Ar which were excited by the pulsed irradiation of electrons by using a 45 MeV linear accelerator were investigated. A new broad band, probably due to the transition between the upper molecular states, was observed at 1200 to 1400 nm. The effects of O2 and SF6 on this band were studied.
The Osmotic and Activity Coefficients of Quaternary Phosphonium Halides in Aqueous Solutions at Freezing Point
Authors: Wakabayashi Toshiki , Takaizumi Katsuko
Published: July 2006

The osmotic and activity coefficients have been obtained cryoscopically for (n-Bu)4−nPhnPX(n=0–4, X=Cl, Br) in aqueous solutions at freezing point. The γ± decreases with increasing n, for both the chloride and the bromide salts. With the chloride salts, γ±’s for the salts of n from 0 to 2 show positive deviation from the Debye-Hückel limiting law as concentration increases, whereas γ±’s for others show negative deviation. Replacement of the anion from Cl− to Br− results in lower γ±’s for the salts of n from 0 to 2, but this elevates the other γ±’s. These results were interpreted qualit tively in terms of the cosphere overlap model by Desnoyers et al., by assuming a hydrophilic character of the present phenyl group. An attempt was made to evaluate the pairwise interaction coefficients(B*) and to estimate the contributions to B* from the interactions, butyl-Cl− and phenyl-Cl−.
Reactions of Azepine, Diazepine, Tropone, and Cyclopentadienone Derivatives with Some Chlorosilane Derivatives in the Presence of Magnesium
Authors: Saito Katsuhiro , Kojima Hisashi , Okudaira Tsuguo , Takahashi Kensuke
Published: July 2006

The reaction of 1-ethoxycarbonyl-1H-azepine with chlorosilane derivatives in HMPA in the presence of magnesium afforded the silanol derivatives, which upon heating gave the corresponding siloxane derivatives. In the same manner, tropone and 2,5-dimethyl-3,4-diphenylcyclopentadienone afforded the reduced dimers of them. However, tetraphenylcyclopentadienone and 2,5-dimethoxy-3,4-diphenylcyclopentadienone were reduced to the corresponding cyclopentenones under the reaction conditions. These reactions are considered to proceed via the corresponding radical anions which are formed by electron transfer from magnesium.
A Route from 1,1,1,3-Tetrachloro-3-phenylpropane to Ethynyl Phenyl Ketone Involving Elimination of Hydrogen Chloride and 1,3-Proton Transfer
Authors: Akiyama Takeo , Yoshida Yasuki , Hanawa Tokiko , Sugimori Akira
Published: July 2006

The treatment of 1,1,1,3-tetrachloro-3-phenylpropane with alkali in ethanol affords ethynyl phenyl ketone and its acetal in good yields. This reaction proceeds through the elimination of hydrogen chloride and an efficient 1,3-proton transfer catalyzed by base. Ethyl cinnamate is obtained in only 2% yield.
Kinetics of Oxidative Coupling of Phenols. Oxidation of Guaiacol by Alkaline Hexacyanoferrate(III)
Authors: Singh Sukham Nabakishwar , Bhattacharjee Mitra , Mahanti Mahendra Kumar
Published: July 2006

The reaction between guaiacol and alkaline hexacyanoferrate(III), at constant ionic strength, gave a coupled product, 3:3′-dimethoxydiphenoquinone. The rate of the reaction was dependent on the first orders of the concentrations of substrate, oxidant, and alkali. The rate determining step involved the formation of a radical intermediate, which was detected by ESR spectroscopy.
Solid State Reactions of 2,4-Dinitrotoluene. Detection and Semiquantitative Determination of Indole, Diphenylamine, and p-Dimethylaminobenzaldehyde
Authors: Nabi Syed Ashfaq , Mohammad Ali , Qureshi Pushkin Mohammad
Published: July 2006

Solid state colour reactions of 2,4-dinitrotoluene have been used for the selective detection of organic compounds and semiquantitative determination of indole, p-dimethylaminobenzaldehyde and diphenylamine in a glass capillary. Phloroglucinol and tryptophan do not interfere with the determination of indole. A glass wool plug modification makes the selective test almost specific for indole.
Direct Measurement of the Interaction Energy between Solids and Gases. X. Acidic Properties of Hydroxyl Sites of H–Y Zeolite Determined by High-temperature Calorimetry
Authors: Mitani Yoshio , Tsutsumi Kazuo , Takahashi Hiroshi
Published: July 2006

Differential heats of adsorption of bases on H–Y zeolite were measured at 473 K and separated into those evolved at 3640 and 3550 cm−1-OH sites respectively by a combined use of calorimetric and IR measurements, and then the acid strength of two OH sites was compared each other. In case of pyridine, heats of adsorption were larger on OH sites at 3640 cm−1 than 3550 cm−1, which was in agreement with the results obtained by many authors by IR measurements. However, heats of adsorption on 3640 cm−1-OH sites were only slightly higher than those on 3550 cm−1-OH sites in case of ammonia, and almost the same in case of piperidine. The difference in heats of adsorption between the OH sites was explained by positional difference between the two OH sites, molecular size of the titrated bases and proton mobility induced by a strong base. The order of the strength of bases was determined by replacing a base molecule with another one on H–Y zeolite as follows; piperidine>pyridine>ammonia. This differs from the order expected from their pKa values in solution.
Competitive Effects in Polymer Adsorption and Exchangeability of Adsorption Layer
Authors: Furusawa Kunio , Yamamoto Kazuaki
Published: July 2006

Critical experimental data on competitive adsorption and exchangeability of adsorbed polymer are produced under the various conditions using the gel permeation chromatography technique. It is apparent that the competitive effects and the exchangeability were found to depend not only on the molecular weight of the polymer, but also on the concentration of each component at which the corresponding adsorption is carried out. This can be explained as follows; the conformation of the adsorbed polymer would be influenced extensively by the polymer concentration in bulk. The polymer molecules adsorbed from a dilute solution would take on a flat conformation being rich in train segments, but the polymer layer formed under a concentrated solution would occupy a small of sites and adopt an extended loop configuration which would be desorbed more easily than the flat one. Also, in the mixed sample the effects of adsorption Kinetics play an important role on the structure of the adsorption layer, because at first the surface is convered by an adsorption layer of small components due to its rapid adsorption rate.
Crystal and Molecular Structure of (+)-(3R,4S,8R,9S)-Quinidinium Δ-(−)546-Bis(oxalato)(1,10-phenanthroline)chromate(III) Monohydrate and Its Implication in the Pfeiffer Effect of the Corresponding System
Authors: Ohbo Hiroyuki , Okazaki Hiroshi , Miyoshi Katsuhiko , Yoneda Hayami
Published: July 2006

The crystal structure of the title compound d-quinidinium (−)546-[Cr(ox)2(phen)]·H2O has been determined by a single-crystal X-ray analysis and refined to R=0.078 for 2172 reflections. The crystals are orthorhombic, space group P212121 with unit cell dimensions of a=9.943(2), b=11.265(2), c=30.716(6) Å, and Z=4. The known configurations of d-quinidinium ion revealed that (−)546-[Cr(ox)2(phen)]− has a Δ configuration in accord with the earlier assignment based on its CD spectrum. Following characteristics were noted with regard to intermolecular interactions in the crystal; i) complex anions are linked with one another through the hydrogen bonds to intervening water molecules, to form chains along two-fold screw axes parallel to the a-axis, ii) intermolecular hydrogen bonds connect the complex anion closely with d-quinidinium cation which is further hydrogen-bonded to each other forming infinite chains along two-fold axes parallel to the b-axis, and iii) partial stacking is observed between aromatic phen and quinoline rings. These interaction modes were discussed in relation to the Pfeiffer Effect of the corresponding system in water.
Synthesis of Some New Aza Tricyclic Compounds with a Cyclopropane Ring via Photolysis of Dihydromayurone Oximes and the Related Compounds
Authors: Takahashi Hajime , Ito Masaaki
Published: July 2006

Oximation of dihydromayurone and 6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one gives new isomeric oximes, respectively. The Beckman rearrangement of (Z)- or (E)-dihydromayurone oxime and (Z)- or (E)-6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one oxime with polyphosphoric acid takes place prior to the Z-E equilibration of these isomers, respectively. Photolysis of the oximes gives two pairs of the isomeric lactams, 4-aza-8,12,12-trimethyltricyclo[6.4.0.01,3]dodecan-5-one, 5-aza-8,12,12-trimethyltricyclo[6.4.0.01,3]dodecan-4-one, 4-aza-7,11,11-trimethyltricyclo[5.4.0.01,3]undecan-5-one, and 5-aza-7,11,11-trimethyltricyclo[5.4.0.01,3]undecan-4-one. The reaction of either dihydromayurone or 6,10,10-trimethyltricyclo[4.4.0.01,3]decan-4-one with hydroxylamine-O-sulfonic acid in acetic acid affords only the lactam arising from the migration of the less substituted carbon.
Double Cycloaddition Reaction of Imidazolium Methylides. Intermolecular 1,3-Dipolar and Intramolecular Diels-Alder Cycloaddition Reactions
Authors: Tsuge Otohiko , Kanemasa Shuji , Takenaka Shigeori
Published: July 2006

Such imidazolium methylides as imidazolium dicyanomethylide and bis(ethoxycarbonyl)methlide react with the methylenecyclopropenes with unsaturated substituents at the 4-position in the fashion of double cycloaddition reaction, leading to the novel cage compounds, which involves an intermorecular 1,3-dipolar cycloaddition reaction and an intramolecular Diels-Alder reaction.
Pseudo-sugars. X. Synthesis of Several Branched-chain Unsaturated Cyclitols and Their Derivatives
Authors: Ogawa Seiichiro , Hattori Takao , Toyokuni Tatsushi , Suami Tetsuo
Published: July 2006

Some racemic (hydroxymethyl)cyclohexenepolyols and their derivatives of biological interest have been synthesized from Dl-1,2,3-tri-O-acetyl-(1/2,3)-4-methylene-5-cyclohexene-1,2,3-triol derived from the corresponding dibromide by treatment with sodium acetate in hexamethylphosphoric triamide.
IR Spectra of Solid State Reaction Products of TTF and Iodine
Authors: Matsuzaki Susumu , Koga Naoto , Moriyama Ichiro , Toyoda Koichi
Published: July 2006

IR spectra of the mixture of tetrathiafulvalene (TTF) and iodine showed that the two components react with each other in the solid state. Spectral changes with an increase in iodine content were analyzed on the basis of the spectra of TTF and the cations, and it was found that TTF is oxidized by iodine up to the dication in the solid state in contrast to the reaction in solution.
Oxygen Evolution Reaction on Composite Cobalt Borides
Authors: Osaka Tetsuya , Iwase Yoshio , Kitayama Hiroshi , Ichino Toshihiro
Published: July 2006

The Oxygen evolution reaction on cobalt borides and composite cobalt borides was investigated in a 6M KOH solution (1 M=1 mol dm−3) using the factor of the magnetic properties. In the system of cobalt borides (Co:B=3:1) prepared at various sintering temperatures, the boride having a higher saturation magnetization revealed a higher activity of the oxygen evolution reaction. In the system of composite cobalt borides which have various magnetic moments, μB, a clear correlation between the activity of the oxygen evolution reaction and the saturation magnetization (or magnetic moment, μB) was observed for several composite cobalt boride species (i.e., Co–Fe–B, Co–Ni–B, Co–Mn–B, and Co–B). Among the composite cobalt boride species, the cobalt iron boride (Co:Fe:B=1:2:1) sintered at 450 °C showed the highest activity of oxygen evolution reaction in a 6 M KOH solution. The conditions of oxide formation on Co–Fe–B(1:2:1) and on Co–B(3:1) in a 6 M KOH solution were compared with those on cobalt by means of voltammetry and chronopotentiometry. It was concluded that the ease and stability of oxide films in higher oxidation states are strongly correlated to the activity of the oxygen evolution reaction which occurs on more highly oxidized oxide films.
Crystal and Molecular Structure of Methyl d-Tetronitroside
Authors: Hirayama Noriaki , Kasai Masaji , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio
Published: July 2006

The structure of the novel sugar, methyl d-tetronitroside [methyl 2,3,4,6-tetradeoxy-4-(methoxycarbonylamino)-3-C-methyl-3-nitro-d-xylo-hexopyranoside], was determined by X-ray analysis. This compound is a structural component of the antitumor antibiotics, tetrocarcins. The space group is P21 with a=11.782(3), b=10.271(2), c=11.636(3) Å, β=105.12(4)°, and Z=4. The structure was solved by direct methods, and least-squares refinement using 2503 reflexions gave the final R value of 0.079. Both the two independent molecules take a 4C1 chair conformation and they are connected together through two hydrogen bonds. Although the average C–C distance in the rings is 1.527 Å, the C(2)–C(3) distance is significantly long (average 1.546 Å) due to the steric hindrance by the nitro groups.
The Structure of Liquid Formamide Studied by Means of X-Ray Diffraction and ab Initio LCGO-MO-SCF Calculations
Authors: Ohtaki Hitoshi , Funaki Atsushi , Rode Bernd M , Reibnegger Gilbert J
Published: July 2006

The molecular and liquid structures of formamide have been studied by means of X-ray diffraction. Relative stabilities of aggregates of formamide molecules have been calculated by using the ab initio LCGO-MO-SCF procedure and minimal basis sets. The atomic distances within a formamide molecule and the intermolecular N···O distance between the hydrogen–bonded molecules are determined by the X-ray diffraction experiment as follows: C=O: 1.24(1) Å, C–N: 1.33(1) Å, N···O (intramolecular): 2.25(2) Å, and N···O (intermolecular): 3.05(5) Å. The intermolecular (Remark: Graphics omitted.) bond angle (Θ) is about 120°. It is concluded from the X-ray diffraction experiment that liquid formamide mainly consists of the chain-like hydrogen–bonded structure of formamide molecules by combining through –NH2···O=CH– interactions. The conclusion is supported by the ab initio calculations. Formation of ring-dimers in the liquid formamide has not been confirmed by the X-ray diffraction study, although a possibility of the formation of the ring-dimer structure as another constituent of liquid formamide is suggested from the ab initio calculations.
Determination of Diffusion Coefficients of Metals Dissolved in Mercury by Double Potential Step Chronoamperometry at Hanging Mercury Drop Electrodes
Authors: Park Sang Yun , Aoki Koichi , Tokuda Koichi , Matsuda Hiroaki
Published: July 2006

Double potential step chronoamperometry at the hanging mercury drop electrode is proposed for determination of diffusion coefficients of metals dissolved in mercury. The expression for chronoamperometric curves is obtained, from which the algorithm is derived for evaluating diffusion coefficients of metals. The diffusion coefficients of lead, zinc, and cadmium in mercury at 25 °C were determined by the present technique.
Polarography of Pb(II) Complexes with N,N′-Bis(2-hydroxyethyl)ethylenediamine-N,N′-diacetic Acid
Authors: Matsuo Tsutomu , Masuda Yoshitaka , Sekido Eiichi
Published: July 2006

The electrochemical behaviour of the Pb(II)–N,N′-Bis(2-hydroxyethyl)ethylenediarnine-N,N′-diacetic acid(H2bhedda=H2L) system has been examined by means of d.c. polarography. Two well-defined polarographic reduction waves were observed. The mechanisms of the electrode reaction for the two waves were elucidated. The kinetic parameters of the irreversible reduction of the complexes have been evaluated; kj1=3.80×10−5 cm/s and kj2=5.25×10−16 cm/s. The stability constant of the PbHL+ species is calculated to be 104.45.
Preparation and Properties of Polymers Anchoring Biphenyl-2-ol
Authors: Ishikawa Tomomichi , Asai Satoshi
Published: July 2006

The monomer, 2-biphenylyl acrylate (BPA), was prepared and was polymerized and copolymerized with vinyl acetate (VAc), styrene and N-vinylpyrrolidone. The reactivity ratios of BPA (M1) with VAc were evaluated as r1=4.6+0.4 and r2=0.37+0.08. The polymers were hydrolyzed in methanol–phosphate buffer solution(pH 6 and 8), and the release rate of biphenyl-2-ol from the polymer was investigated.
NMR Study of Protonated Halothiophenes. I. 1H NMR Study of Chlorothiophenium Ions
Authors: Yokoyama Yukihiro , Yamashita Yukihide , Takahashi Kensuke , Sone Tyo
Published: July 2006

Well-resolved 1H NMR signals of the cations formed from chlorothiophenes were observed in the HSO3F or AlCl3–HCl–CH2Cl2 system. Chlorothiophenes are protonated exclusively at the position adjacent to sulfur, either with or without substituents. The protonation of 2-chloro-5-methylthiophene occurs at the 5-position, and, in the HSO3F system, the cation 5H-2-chloro-5-methylthiophenium ion thus formed undergoes an irreversible 2,5-hydrogen shift.
Reaction of 1,8-Naphthalenediamine with Dimethyl and Diethyl Acetylenedicarboxylates
Authors: Honda Koichi , Nakanishi Hiroshi , Yabe Akira
Published: July 2006

1,8-Naphthalenediamine reacted with dimethyl and diethyl acetylenedicarboxylates, giving rise to tetrahydronaphtho[1,8-ef]diazepinones (2), dihydroperimidines (3) and bis(enamino)fumarates (4). The relative yields of 3 and 4 depended on the reaction conditions, while products 2 were always very minor. Products 4, the yields of which increased considerably in the presence of a large excess of the acetylenes, underwent cyclization at 230 °C leading to quinolinoquinolinediones.
Behavior of Trajectory with Stable and Unstable Limit Cycles in the Oregonator Model for the Belousov-Zhabotinskii Reaction
Authors: Sakanoue Shinji , Murase Chiaki , Endo Mitsuo
Published: July 2006

Computer simulations and a theoretical analysis of the Oregonator model of the Belousov-Zhabotinskii reaction are made based on Tyson’s equation. The behavior of the amplitudes of the unstable limit cycle near the transition point, pc, can be explained theoretically fairly well by the Landau theory. The global behavior of one stable limit cycle and one unstable limit cycle is examined by means of simulations. The existence of a triple point at which three different global states coexist has been suggested.
Acid-Base and Catalytic Properties of ZrO2–SnO2
Authors: Wang Gong-Wei , Hattori Hideshi , Tanabe Kozo
Published: July 2006

The acid-base properties of ZrO2–SnO2 with different compositions have been measured by the indicator method and the adsorption with NH3 and CO2 and the catalytic activities studied. The ZrO2–SnO2 (atomic ratio=9 : 1) catalyst which was found to have the highest acid strength and the maximum acid amount exhibited the highest activities for the isomerization of cyclopropane and the dehydration of 2-butanol. The activities of the catalysts with different compositions for the two reactions correlated with the acidic properties. On the other hand, the activities for the isomerization of 1-butene and the decomposition of diacetone alcohol (4-hydroxyl-4-methyl-2-pentanone) correlated with the basic properties. The activity for the dehydrogenation of 2-butanol was found to increase with an increase of the SnO2 content. The active sites on the ZrO2–SnO2 catalysts are discussed.
Emission Spectra of Toluidines by Controlled Electron Impact
Authors: Ogawa Teiichiro , Oomori Takayuki , Kawazumi Hirofumi
Published: July 2006

The spectra of o-, m-, and p-toluidines show an intense band of the S1-S0 transition of the parent molecule, and lines and bands of fragment species such as H, CH, C2, CN, and NH.
The Heats of Solution of Optically Active Amino Acids, the Corresponding Racemic Amino Acids, and Their Derivatives in Water
Authors: Matsumoto Masayuki , Amaya Kazuo
Published: July 2006

The heats of solution of normal and branched α-amino acids and of their derivatives in water were measured at 298.15 K. The experimental results show that the racemates are more stable than optically active compounds, except for glycylleucine, and that the differences in the heat of solution between the two species for branched compounds are nearly constant, about 2 kJ mol−1, while those for the normal compounds are dependent on the number of carbon atoms in the alkyl chains.
Thermally Derived Dimers of o-Vinylphenol: trans- and cis-2′-Hydroxy-4-methylflavans
Authors: Chen Yen-Yuan , Oshima Ryuichi , Kumanotani Ju
Published: July 2006

o-Vinylphenol dimerizes thermally to yield quantitatively two isomers, trans- and cis-2′-hydroxy-4-methylflavans. The analysis of the dimers of o-vinylphenol-O-d suggests that a quinone-methide intermediate is responsible for the formation of these flavanoid compounds.
Enrichment and Determination of Trace Amounts of Iron as the Colored Complex on the Thin Layer of Ion-exchange Resins
Authors: Ohzeki Kunio , Satoh Yuhko , Kawamura Yoshito , Kambara Tomihito
Published: July 2006

A trace amount of iron was extracted as the complex with 4,7-diphenyl-1,10-phenanthrolinedisulfonic acid from aqueous solution using finely divided anion and cation exchange resins. The mixed resins were collected on a filter paper as the disk of thin layer. The colored complex in the resin phase was determined with the use of a densitometer at 540 nm. The calibration graph was linear over the range 0.1–0.5 μg of iron(II). The relative standard deviation for 0.5 μg of iron(II) in 50 ml of the test solution was 2.1% (n=5). The method was applied to the trace determination of total iron in water samples.
The Synthesis and Reaction of Spiro[oxolane-2,2′-piperazine]-3′,6′-diones with N-Bromosuccinimide in the Presence or Absence of Water
Authors: Shin Chung-gi , Sato Yoshiaki , Honda Seiji , Yoshimura Juji
Published: July 2006

The compound 3-(3-hydroxy)propylidene-piperazine-2,5-dione, derived from ethyl 4-ethoxycarbonyl-2-chloroacetylamino-2-butenoate, was treated with N-bromosuccinimide (NBS) in chloroform to give the spiro[oxolane-2,2′-piperazine]-3′,6′-dione derivative. The spiro compound was further treated with NBS in water to give the corresponding spiro[oxolane-2,2′-piperazine]-3′,5′,6′-trione and -3′,6′-dione-5′-ol. The latter compound and a new spiro-5′,6′-dione-3′-ol derivative were also obtained by the reduction of the spiro-3′,5′,6′-trione. The structural confirmation of all the new products is discussed.
Asymmetric Hydrogenations of N-Pyruvoyl-(S)-amino Acid Esters
Authors: Harada Kaoru , Munegumi Toratane
Published: July 2006

N-[(R)-Lactoyl]-(S)-amino acid isobutyl esters were obtained with a diastereoisomeric purity up to 34%, through the catalytic hydrogenations of N-pyruvoyl-(S)-amino acid (alanine, valine, and leucine) isobutyl esters over palladium on charcoal. It was found that a linear correlation exists between the dielectric constant of the solvent and the diastereoisomeric purity of the product obtained by catalytic hydrogenation. The ratio of N-[(S)-lactoyl]-(S)-amino acid isobutyl ester to N-[(R)-lactoyl]-(S)-amino acid isobutyl ester increased with the decrease of the dielectric constant of the solvent. This solvent effect could be explained by the chelation mechanism. The temperature effect on the asymmetric catalytic hydrogenation was also studied.
Silicon–Carbon Unsaturated Compounds. XVI. Photorearrangement of an Adduct Derived from Reaction of a Silicon–Carbon Unsaturated Compound with t-Butyl Alcohol
Authors: Ishikawa Mitsuo , Oda Michio , Nishimura Kunio , Kumada Makoto
Published: July 2006

Photolysis of pentamethylphenyldisilane in the presence of t-butyl alcohol gave a mixture of adducts which were readily oxidized to 1-(t-butoxydimethylsilyl)-2-(trimethylsilyl)benzene by oxygen. Photolysis of p-tolylpentamethyldisilane in the presence of t-butyl alcohol afforded 4-(t-butoxydimethylsilyl)-1-methyl-5-trimethylsilyl-1,3-cyclohexadiene (4) as a primary photoproduct. The UV-irradiation of 4 gave ring opened products, 2-(t-butoxydimethylsilyl)-5-methyl-1-trimethylsilyl-1,3,5-hexatriene and 2-(t-butoxydimethylsilyl)-5-methyl-3-trimethylsilyl-1,3,5-hexatriene in a ratio of 1.8/1.
The Thermal Decomposition of Manganese(III) Phosphate Monohydrate
Authors: Narita Eiichi , Okabe Taijiro
Published: July 2006

Manganese(III) phosphate monohydrate begins to decompose at 200 °C by the dehydration accompanying the reduction of manganese(III) and changes completely to manganese(II) pyrophosphate at 500 °C. The reaction order and activation energy for the reduction process are 1.3 and 176.8 kJ mol−1, respectively.
Oxidation of 9-Xanthenones with Lead(IV) Acetate. Formation of Di-γ-lactones
Authors: Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The oxidation of 9-xanthenones with lead(IV) acetate afforded 3a,3b,6a,12b-tetrahydro-2H-difuro[3,2-a:3′,2′-c]xanthene-2,5,7(3H,6H)-triones in addition to other products. Characterization of the di-γ-lactones and the difference between the oxidation reaction of lead(IV) and manganese(III) acetates in the 9-xanthenone system are discussed.
Synthesis of 3a,8a-Dihydrocyclopent[a]inden-3(8H)-one
Authors: Sugihara Yoshikazu , Sugimura Takashi , Murata Ichiro
Published: July 2006

3a,8a-Dihydrocyclopent[a]inden-3(8H)-one (6) was prepared from a known compound, 2,2-dichloro-2,2a,7,7a-tetrahydro-1H-cyclobut[a]inden-1-one, by a simple ketone 1,2-transposition followed by introduction of a double bond. The photochemical behavior of 6 was also examined.
2-(4-Chlorophenylseleno)-2-butenal as a New Dienophile for Diels-Alder Reaction
Authors: Uneyama Kenji , Takano Kunikazu , Torii Sigeru
Published: July 2006

Diels-Alder reaction of 2-(4-chlorophenylseleno)-2-butenal with butadiene, isoprene, trans 1,3-pentadiene, and cyclopentadiene provided the corresponding adducts in 80–90% yields, which were subsequently transformed into cyclohexadienal derivatives.
The Crystal Structure of Tetramethyltetraselenafulvalenium Perrhenate, (TMTSF)(ReO4)(C2H3Cl3)0.25
Authors: Kobayashi Hayao , Kobayashi Akiko , Sasaki Yukiyoshi , Saito Gunzi , Inokuchi Hiroo
Published: July 2006

The crystal structure of (TMTSF)(ReO4)(C2H3Cl3)2.25 was determined. The crystals are monoclinic P2/c, a=18.573(3), b=7.418(2), c=26.210(6)Å, β=107.85(2)°, Z=8. TMTSF molecules are stacked to form diadic columns along the b axis. The mode of intermolecular overlapping between adjacent TMTSF molecules shows a new mode of overlapping. The strong alternation of the intermolecular Se–Se distances along the TMTSF columns indicates that this compound is a Peierls insulator, which is consistent with the semiconducting behavior. The Peierls instability is accompanied by a bending distortion of the planar TMTSF molecules. The roomtemperature conductivity is 3×10−4 (Ω cm)−1, and the activation energy is 0.18eV. There are some short Se–O contacts between ReO4 anions and TMTSF stacks. The solvent molecnles (C2H3Cl3) are located in the channel formed along the b axis.
Thermodynamics of the Electrocapillarity of Oil–Water Interfaces
Authors: Kakiuchi Takashi , Senda Mitsugi
Published: July 2006

General electrocapillary equations for the interfaces between two immiscible or partially miscible electrolyte solutions have been derived. The theory includes both nonpolarized and ideal polarized interfaces. The electrocapillary equation for the latter has been derived from the equation for the former as a special case where no common ionic species are distributed between the two phases. Implications of the general electrocapillary equation for oil–water interfaces are indicated.
Retention Behavior of Iron(III) Chelates with Amine-N-carboxylic Acids on Silica-gel and Octadecyl-silica Columns
Authors: Yamaguchi Akihiro , Toda Atsuko , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

The separation of iron(III)–edta, –methyl-edta, –dtpa, and –cdta was investigated by high performance liquid chromatography on silica-gel (ZORBAX SIL) and octadecyl-silica (ZORBAX ODS) columns. The chelates were retained on both columns from phosphate buffer mobile phase of pH 3, while the baseline separation was not achieved on the ODS column. The degree of increase in retention caused by the addition of tetrabutylammonium bromide to the eluent was greater on the ODS column than on the silica-gel column, and well separated chelates were eluted in the order, iron(III)–edta, –methyl-edta, –dtpa, and –cdta on both columns.
Synthesis of Mesoionic Triazolopyridine. II. N-Acylation of 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one
Authors: Saito Akio , Shimizu Bunji
Published: July 2006

N-Acyl and N-alkoxycarbonyl mesoionic triazolopyridines were synthesized by selective N-acylation of 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one. Some properties of these new-type azolides were also investigated.
Functionalization of (R)-3-(3-Acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one and Some Related Compounds
Authors: Matsumoto Takashi , Imai Sachihiko , Ondo Kenji , Kataoka Hideo , Kato Kyoko
Published: July 2006

Oxidation of (R)-3-(3-acetoxypropyl)-2,3-dihydro-6-hydroxy-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one with Fremy’s radical afforded the corresponding o-quinone, which was converted into (R)-5,6,8-triacetoxy-3-(3-acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one and its 5,6,9-triacetoxy isomer. (R)-3-(3-Acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one was also converted into (R)-9-acetoxy- and (R)-5,8,9-triacetoxy-2,3-dihydro-7-isopropyl-3-(3-methoxypropyl)-3,4-dimethylnaphtho[2,3-b]-furan-2-one. Transformation of (R)-2,3-dihydro-6-hydroxy-3-(3-hydroxypropyl)-7-isopropyl-3,4-dimethylnaphtho-[2,3-b]furan-2-one into (R)-6-acetoxy-3-allyl-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one was also achieved.
Synthetic Studies on the Validamycins. IX. Synthesis of Some Racemic Isomers of Validoxylamine A
Authors: Toyokuni Tatsushi , Ogawa Seiichiro , Suami Tetsuo
Published: July 2006

Two racemic isomers of validoxylamine A have been synthesized by use of coupling reactions of the protected Dl-validamine and the allylbromides, the precursors of the unsaturated branched-chain cyclitol moiety. The racemic diastereomers thus formed can be separated by chromatography on silica gel. It indicates that optically pure validoxylamine A analogs should be obtained if chiral validamine derivative is used in place of the racemate.
Stereoselective Syntheses of 3-Acetyl-1,2-dimethyl-1-cyclopentanols. Syntheses of dl-Plinols A, B, and C
Authors: Imagawa Takeshi , Matsuura Kazuyuki , Murai Nobuyuki , Akiyama Tetsuo , Kawanisi Mituyosi
Published: July 2006

c- and t-3-Acetyl-1,c-2-dimethyl-r-1-cyclopentanols and c-3-acetyl-1,t-2-dimethyl-r-1-cyclopentanol are synthesized stereoselectively and dl-plinols A, B, and C are prepared therefrom.
Ion-pair Extraction of Pyrocatechol Violet into Chloroform with Quaternary Ammoniun Salts
Authors: Hirano Yoshio , Ando Masahito , Naito Kunishige , Takei Shinsuke
Published: July 2006

An extraction method was first examined for establishing possible distributions of surface-active dodecyltrimethylammonium chloride (DTMAC) and non-surface active tetrabutylammonium chloride (TBAC) between aqueous and organic phases. Both quaternary ammonium salts seem to be present in the form of a free ion in the aqueous phase and in the forms of an ion pair(monomer) and a dimer in the organic phase. A possible distribution of DTMAC in the organic phase was confirmed spectrometrically by following the formation of a 1 : 1 DTMAC–iodine adduct in chloroform solution. On the basis of the possible distribution of quaternary ammonium salts, an ion pair forming extraction of Pyrocatechol Violet (PV) can be successfully interpreted in terms of the anion-exchange mechanism.
The Resonance Raman Spectra of (meso-Tetraphenylporphinato)cobalt(II)-d0[Co (TPP)-d0], -d8, and -d20
Authors: Kozuka Muneteru , Iwaizumi Masamoto
Published: July 2006

The resonance Raman spectra of the title complexes were measured, and a normal coordinate analysis was carried out. The 1604 and 1243 cm−1 polarized bands of Co(TPP)-d0 were assigned to resonance-enhanced phenyl modes. This suggests the presence of appreciable porphinephenyl resonance interaction in this complex.
Single-step Lithium-ion Exchange on α-Hafnium Phosphate
Authors: Tomita Isao , Magami Kazuo , Watanabe Hiroshi , Suzuki Koji , Nakamura Toshihiro
Published: July 2006

Forward and backward pH titration curves were measured for lithium-ion exchange on crystalline α-hafnium phosphate. The forward reaction proceeded in a single step, in contrast to the corresponding process in α-zirconium phosphate. In the backward process, no intermediate crystalline phases were observed during the exchange, and the exchanger was gradually converted into gel.
Bis(crown ether) Dyes Incorporating Azophenol Structure
Authors: Kitazawa Sadaya , Kimura Keiichi , Shono Toshiyuki
Published: July 2006

Three types of bis(crown ether) dyes bearing one or two azophenol units were synthesized, which may be expected to show different cation-complexing properties from the corresponding monocyclic crown ether dyes. The extraction of alkali and alkaline-earth metal salts with the crown ether dyes suggested that some cooperative action of the two adjacent crown ether moieties of the bis(crown ether)s occurs on complexing metal cations, although the bis(crown ether) effect is not very remarkable.
A Rubrene Problem. Reaction of 3,3,4,4-Tetrabromo-1,2-bis(diphenylmethylene)cyclobutane and Dichloroacetic Acid
Authors: Toda Fumio , Sasaoka Michio , Todo Yozo , Iida Kunio , Hino Toru , Nishiyama Yasuaki , Ueda Hideo , Oshima Tokio
Published: July 2006

Heating of 3,3,4,4-tetrabromo-1,2-bis(diphenylmethylene)cyclobutane in dichloroacetic acid afforded bridgehead olefin, 7-bromo-1,4,8-triphenyl-2,3-benzobicyclo[3.3.0]octa-2,4,7-trien-6-one, and spiroketone, 2-bromo-2′,3-diphenylspiro[1H-indene-1,1′(4′H)-naphthalen]-4′-one (13). Mechanism of the reaction was discussed. X-Ray structural study of the spiroketone 13 was also reported.
Some Problems Associated with the Exact Solution Conformation of Poly(α-l-glutamic acid) as Determined by Optical Methods
Authors: Yamaoka Kiwamu
Published: July 2006

By combining the experimental data on circular dichroism and light scattering, the helical conformation of poly(Glu) in 0.15 mol dm−3 NaCl solutions was estimated. The axial translation per residue was probably in the range of 1.2–1.3 Å for the unaggregated helix, while the persistence length was ca. 120 Å for the random-coil.
Synthesis of Diphenyl-substituted Flavonoid Compounds on Both Benzene Rings
Authors: Matsumura Hisashi , Tsuchiya Toshio , Imafuku Kimiaki
Published: July 2006

Condensation of o-hydroxyacetophenone and its 3- and 5-phenyl-substituted compounds with 2- or 4-methoxy-biphenyl-3-carbaldehyde gave six mono- and diphenyl-substituted 2′-hydroxychalcones (5a–f), which were cyclized with alkali to afford the flavanones. The chalcones 5a–f were also converted to the corresponding flavones via chalcone bromides.
Convenient Synthesis of (1-Alkyl-2-hydroxyethyl)diphenylphosphine Oxides
Authors: Yamashita Mitsuji , Yamada Manabu , Tsunekawa Kenji , Inokawa Saburo
Published: July 2006

(1-Alkyl-2-hydroxyethyl)diphenylphosphine oxides were synthesized from the corresponding (1-alkyl-2-oxoethyl)diphenylphosphine oxides in excellent yields. The structures of 2-hydroxy derivatives and their acetates were confirmed by elemental and spectral analyses.
Mechanochemical Change in the Solid State of Hexobarbital
Authors: Ikekawa Akiko , Hayakawa Sohachiro
Published: July 2006

The effect of ball-milling on X-ray diffraction diagrams, IR spectra, DTA and DSC thermograms of hexobarbital was investigated. It was found that the regularity at the crystal part changed upon ball-milling without any diluent. In addition to this change, an amorphous part increased upon ball-milling with microcrystal-line cellulose (MCC). The solubility in a KH2PO4–Na2HPO4 buffer solution (pH 6.0) also increased upon ball-milling with MCC, though the solubility did not change without MCC. The analysis of IR spectra indicated that hydrogen bonds were formed between the C=O group of hexobarbital and the OH group of MCC upon ball-milling. Both the increase in the amorphous part and solubilization of hexobarbital upon ball-milling were attributed to the stabilization of the amorphous state caused by the interaction with MCC.
Convenient Methods for the Preparation of p-Dialkylaminophenylacetylenes
Authors: Akiyama Shuzo , Nakatsuji Shin’ichi , Yoshida Keiko , Nakashima Kenichiro , Hagiwara Toshimitsu , Tsuruta Haruki , Yoshida Toshio
Published: July 2006

Two convenient methods for the preparation of p-dialkylaminophenylacetylenes are reported: a) Dehydrobromination of the brominated compounds obtained easily from the dialkylamino substituted cinnamic acids in acetic acid instead of chloroform; b) dehydrochlorination of the 2-chlorostyrene derivative obtained from the reaction of p-dimethylaminobenzaldehyde with chloromethylenetriphenylphosphorane.
Circular Dichroism of Chromium(III) Complexes. VIII. Circular Dichroism Spectra of Mixed Diamine Complexes of trans-[CrF2(N)4]+ Type
Authors: Kaizaki Sumio
Published: July 2006

The ligand field absorption and circular dichroism (CD) spectra were examined not only for trans-difluoro bis(diamine)chromium(III) complexes with two identical chiral diamines but also for nine new mixed diamine complexes of the same type with different diamines, which were ethylenediamine, trimethylenediamine, (R)- and (S)-propylenediamine, (1R, 2R)-1,2-cyclohexanediamine, (2R, 4R)- and (2R, 4R)-2,4-pentanediamine. The additivity of the CD contributions from the individual chiral diamines were substantiated for most of these complexes. On this basis, the conformational and the vicinal CD contribution due to puckered diamine rings and asymmetric carbon atoms, respectively, were differentiated, and the CD origins of all the present complexes were discussed in connection with stereochemistry.
Circular Dichroism of Chromium(III) Complexes. IX. Circular Dichroism Spectra and Stereochemistry of Dinitritobis(diamine)chromium(III) Complexes
Authors: Kaizaki Sumio
Published: July 2006

The circular dichroism (CD) spectra of optically active dinitritobis(diamine)chromium(III) complexes were measured in the visible and near-ultraviolet region, where the diamines used were ethylenediamine, trimethylenediamine, (R)-propylenediamine, (1R, 2R)-1,2-cyclohexanediamine, (2R, 4R)- and (2R, 4S)-2,4-pentanedianiine. The stereochemistry and the conformational (rotational) isomerism of coordinated nitrito ligands were discussed on the basis of the solvent-dependent CD spectra in the near-ultraviolet region of an intraligand absorption band localized on nitrito ligands. It is proposed that the CD variation in the intraligand transition region among the complexes concerned is responsible for the chiral arrangement of nitrito ligands. Further, the conformation of trimethylenediamine chelate in the trans-dinitrito-(R)-propylenediamine complex is determined to take a chair form in comparison with the CD behavior of the corresponding (2R, 4S)-2,4-pentanediainine complex.
Asymmetric Cross-coupling of Organozinc Reagents with Alkenyl Bromides Catalyzed by a Chiral Ferrocenylphosphine-Palladium Complex
Authors: Hayashi Tamio , Hagihara Toshiya , Katsuro Yoshio , Kumada Makoto
Published: July 2006

Organozinc reagents, prepared from secondary alkyl Grignard reagents (ArRCHMgCl: Ar=Ph, p-Tol; R=Me, Et) and excess zinc halides, were allowed to react with vinyl bromide and (E)-β-bromostyrene in the presence of dichloro[(R)-N,N-dimethyl-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethylamine]palladium(II) as a catalyst to give the corresponding coupling products of up to 86% enantiomeric excess.