bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal Complexes in Acetic Acid. I. Kinetics and Mechanism of Reactions of Tetra-μ-acetato-dicopper(II) with Lithium Chloride and Hydrogen Chloride
Authors: Funahashi Shigenobu , Nishimoto Tetsuo , Banerjee Pradyot , Sawada Kiyoshi , Tanaka Motoharu 
Published: July 2006

Abstract
Kinetics of reactions of tetra-μ-acetato-dicopper(II) (copper(II) acetate dimer: Cu2(OAc)4) with lithium chloride and hydrogen chloride (XCl where X denotes Li or H) in acetic acid have been studied spectrophotometrically by using a stopped-flow technique with a computer-assisted averaging device. The rate of decomposition of copper(II) acetate dimer to the monomeric chloro complex is expressed as −d[Cu2(OAc)4]/dt=kXCl[Cu2(OAc)4][XCl]. At 25 °C kLiCl=(3.5±0.6)×105 mol−1 kg s−1 (ΔH\eweq=50±10 kJ mol−1 and ΔS\eweq=30±20 J mol−1 K−1) and kHCl=(4.8±1.0)×105 mol−1 kg s−1 (ΔH\eweq=23±10 kJ mol−1 and ΔS\eweq=−60±20 J mol−1 K−1). Mechanisms are proposed for the decomposition of copper(II) acetate dimer and some discussions are made on the difference in reactivities of LiCl and HCl.
Wittig-type Reaction of Dimetallated Carbodianion Species as Produced by Zinc Reduction of gem-Polyhalogen Compounds in the Presence of Lewis Acids
Authors: Takai Kazuhiko , Hotta Yuji , Oshima Koichiro , Nozaki Hitosi 
Published: July 2006

Abstract
Treatment of R1COR2 with a suspension prepared from diiodomethane, trimethylaluminum and excess zinc in tetrahydrofuran at room temperature affords olefins R1R2C=CH2 in fair (R1,R2=alkyl) to good (R1=alkyl, R2=H) yields. The ketone methylenation is better carried with another system consisting of CH2Br2–Zn–TiCl4. Ketones and aldehydes are transformed into α-chloro α,β-unsaturated esters or α,β-unsaturated esters in good yields on treatment with methyl trichloroacetate or t-butyl dichloroacetate (ethyl dibromoacetate) in the presence of diethylaluminum chloride and zinc.
A Re-investigation of the Conformational Interconversion in the 1,2,3,6,7,8-Hexahydropyrene Anion Radical by ENDOR
Authors: Iwaizumi Masamoto , Kita Shouichi , Kohno Masahiro , Isobe Taro 
Published: July 2006

Abstract
The ENDOR spectra of the 1,2,3,6,7,8-hexahydropyrene anion radical were measured at −94–−60 °C. Based on the computer simulation of the temperature-dependent ENDOR spectra, the thermodynamic constants of the conformational interconversion of the anion radical were determined and compared with those previously obtained by ESR spectroscopy.
The Glucosylation of Several Alcohols with Tetra-O-benzyl-α-d-glucopyranose and a Mixture of p-Nitrobenzenesulfonyl Chloride, Silver Trifluoromethanesulfonate, and Triethylamine
Authors: Koto Shinkiti , Sato Tadaaki , Morishima Naohiko , Zen Shonosuke 
Published: July 2006

Abstract
A novel glucosylation of several alcohols using 2,3,4,6-tetra-O-benzyl-α-d-glucopyranose and a ternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine is presented.
The Formation of Two Kinds of Thiophene Derivatives by the Reaction of the 4H-Pyran-4-thione Derivative with Dimethyloxosulfonium Methylide in a One-pot Process
Authors: Yamaoka Hiroshi , Mishima Ikuhiro , Hanafusa Terukiyo 
Published: July 2006

Abstract
The reaction of 2,6-dimethyl-3,5-diphenyl-4H-pyran-4-thione with dimethyloxosulfonium methylide occurred facilely to give two kinds of 2-thienylacetones, accompanied by a five-membered α,β-unsaturated thione, a naphtho-[2,1-b]thiophene derivative, and a hemithioacetal.
The Absorption Spectra of Monolayers of Fat-soluble Vitamins and the Orientations of Their Chromophores
Authors: Matsuki Kazunori , Nagahira Yukio , Fukutome Hideo 
Published: July 2006

Abstract
The UV absorption spectra at normal incidence and the polarized spectra at 45° incidence of monolayers of vitamin K1, α-tocopherylquinone, vitamin E, ergosterol, and vitamin D2 were measured. The absorption peaks of the monolayers of vitamin K1, α-tocopherylquinone, and vitamin D2 shifted to wavelengths longer than those in a hexane solution, while vitamin E and ergosterol showed little shift. The orientations of their chromophores in the monolayers were investigated by means of the dichroic ratios obtained from their polarized spectra. The molecular axes of vitamin K1, α-tocopherylquinone, and vitamin E were found to be oriented in the range from 0° to about 30° against the normals of their monolayer planes. The molecular axis of ergosterol was found to tilt about 24° against the normal of the monolayer plane. For vitamin D2, no reliable conclusion could be obtained as to its orientation.
Interaction of Water with the Surface of Calcite
Authors: Morimoto Tetsuo , Kishi Jiro , Okada Osamu , Kadota Toshie 
Published: July 2006

Abstract
The interaction of water with the surface of ground calcite was investigated by measuring the water adsorption isotherm and the amount of thermally desorbed molecules in vacuo. The results showed that the surface of ground calcite has chemisorbed water at room temperature which can be completely desorbed by evacuation up to 600 °C, and on which water can be physisorbed in a H2O:OH ratio between 1:2 and 1:1, depending on the conditions of the pretreatment. The isosteric heat of the physisorption of water on the hydroxyls showed that the activity of the adsorption sites for water is reduced by treating the sample at higher temperatures or by washing with water. Moreover, it was found that the surface of the calcite sample starts to release CO2 molecules by heat treatment at relatively low temperatures below 300 °C in vacuo, and that the amount of CO2 increases exponentially with an increase in the temperature.
Copper(I) and Copper(II) Complexes of Tripod Ligands, Tris(2-alkylthioethyl)amine
Authors: Suzuki Masatatsu , Kanatomi Hajime , Koyama Hiroyuki , Murase Ichiro 
Published: July 2006

Abstract
A series of five-coordinate copper(II) complexes with tripod ligands, tris(2-alkylthioethyl)amines (NS3–R, R=CH3, C2H5, n-C3H7, i-C3H7, and t-C4H9), [Cu(NS3–R)L](ClO4)n, where L represents Cl−, Br−, I−, NCS−, im(imidazole), py(pyridine) and H2O, n=1 or 2 were prepared and characterized. The electronic, infrared and ESR spectral data suggest that [Cu(NS3–Me)im](ClO4)2 and [Cu(NS3–Me)OH2](ClO4)2 have a five-coordinate square pyramidal geometry, the other complexes having distorted trigonal bipyramidal or trigonal bipyramidal geometry. The copper(I) complexes with NS3–Me, [Cu(NS3–Me)]ClO4 and [Cu(NS3–Me)NCS] were also prepared and characterized.
Electronic Structures and Conformations of N-Benzylideneanilines. II. Photoelectron Spectral Study
Authors: Akaba Ryoichi , Tokumaru Katsumi , Kobayashi Tsunetoshi , Utsunomiya Chikatoshi 
Published: July 2006

Abstract
Electronic structures and molecular conformations have been studied for N-benzylideneaniline and its 2-methyl, 2,6-dimethyl, and their 4-nitro derivatives by photoelectron spectroscopy. The lower energy bands are analyzed in detail, and the twist angles θN of the anilino benzene rings (ring A) about the carbon-nitrogen bonds are estimated by examining the effect caused by a methyl substitution. It is concluded that N-benzylidene-4-nitroaniline takes a more twisted conformation than N-benzylideneaniline.
The Asymmetric Homogeneous Hydrogenation of Olefins with the Rhodium Complexes of (1S,2S)-1,2-Bis(diphenylphosphinamino)cyclohexane and (2S,3S)-2,3-Bis(diphenylphosphinamino)butane
Authors: Onuma Ken-ichi , Ito Tomiyasu , Nakamura Asao 
Published: July 2006

Abstract
The effect of triethylamine on asymmetric hydrogenation has been studied using the cationic rhodium complex of (1S,2S)-1,2-bis(diphenylphosphinamino)cyclohexane or (2S,3S)-2,3-bis(diphenylphosphinamino)butane as a catalyst. By the addition of triethylamine, higher optical yields are achieved in the hydrogenation of (Z)-α-acetamidocinnamic acid and itaconic acid and higher conversion rates are obtained in the hydrogenation of (E)-2-methylcinnamic acid, mesaconic acid, and citraconic acid. The specific effect of triethylamine on the substrates with a carboxyl group may be explained by the ionization of the carboxyl group, which coordinates the catalytic rhodium complex firmly.
A New Bromophenol from the Red Alga Polysiphonia urceolata
Authors: Kurata Kazuya , Amiya Takashi 
Published: July 2006

Abstract
The investigation of the red alga Polysiphonia urceolata afforded a new bromophenol, 3,3′-dibromo-4,4′,5,5′-tetrahydroxybibenzyl. The structure was elucidated by a combination of spectroscopic methods and chemical transformations. Besides this compound, seven known bromophenols were isolated.
The Substituent Effect. 15. The LSFE Treatment of Substituent Effects on Basicities of Pyridines
Authors: Sawada Masami , Ichihara Masaharu , Yukawa Yasuhide , Nakachi Takeshi , Tsuno Yuho 
Published: July 2006

Abstract
The relative dissociation constants of meta and para substituted pyridinium ions in H2O at 25 °C were collected from a number of sources. To understand the actual substituent effects with a combination of inductive (I) and pi-electronic (Pi) effect components, the LSFE equation has been employed statistically for each of the meta and para series.
ΔpK_a=ρ_iσ_i+ρ_π^+σ_π^++ρ_π^-σ_π^-
The results illustrate (1) the I effect from the meta position is 1.2 times more effective than that from the para position, (2) the Pi effects from the para position have clearly different sensitivities for pi-donor (−R) and pi-acceptor (+R) classes of substituents; more exalted and more reduced Pi effects than that involved in a σp° constants for −R and +R groups, respectively. Compared with earlier results from the Taft’s DSP and relevant treatments, the soundness of the dual ρπ approach and, further, the superiority of the LSFE treatment have been demonstrated for the description of substituent effects on basicity changes in pyridines.
Negative Azeotropic Transformation in Mixed Monolayers of Octadecylammonium Chloride and Tetradecanoic Acid
Authors: Motomura Kinsi , Ikematsu Masaki , Hayami Yoshiteru , Matuo Hirosi , Matuura Ryohei 
Published: July 2006

Abstract
The surface pressure of mixed monolayers of octadecylammonium chloride and tetradecanoic acid has been measured as a function of mean area per film molecule at various compositions and temperatures. It has been observed that the transition pressure from expanded to condensed state of either constituent decreases with the addition of the other one. This behavior has been called a negative azeotropy in the two-dimensional state in contrast to the positive azeotropy observed for the ethyl heptadecanoate–tetradecanoic acid system. By applying the thermodynamic treatment, the phase diagram has been constructed and the apparent molar entropy and energy associated with the phase transition have been calculated. The results support the view that the negative azeotropic transformation in the mixed monolayer is brought about by the mutual interaction between octadecylammonium chloride and tetradecanoic acid molecules which is stronger than that between the same kind of molecules.
A Thermodynamic Study on Hydrolytic Reactions of Lead(II) Ion in an Aqueous Solution and Dioxane–Water Mixtures. I. A Potentiometric Study
Authors: Kawai Takayoshi , Ishiguro Shin-ichi , Ohtaki Hitoshi 
Published: July 2006

Abstract
The hydrolytic reactions of lead(II) ions were studied at 25 °C by means of potentiometric titrations by using a glass electrode in water and dioxane–water mixture (dioxane contents: 0.1 and 0.2 mol fractions) containing 3 mol dm−3 LiClO4 as a constant ionic medium. Four complexes, Pb3(OH)33+, Pb4(OH)44+, Pb3(OH)42+, and Pb6(OH)84+ were found in the solvent systems examined at pH\lesssim8, and the formation constant *βpq for the reaction, qPb2++pH2O=Pbq(OH)p(2q−p)++pH+, was determined. The autoprotolysis constants Ki in the same solvent systems were also obtained by use of a hydrogen electrode. The formation constant βpq(=*βpq/Kip) for the reaction, qPb2++pOH−=Pbq(OH)p(2q−p)+ was evaluated by combining the formation constants *βpq and the autoprotolysis constants obtained. The free energy change of transfer from water to a dioxane-water mixture for the reaction could be estimates as ΔGpqt=−RTln{βpq(mix)⁄βpq(aq)}. The values (1/p)ΔGpqt of hydroxo complexes of various metal ions such as lead(II), copper(II), nickel(II), beryllium(II), and cadmium(II) ions were approximately independent of the complexes at a given concentration of dioxane. This result suggested that the formal charge per metal ion of the complex, z′ (=z−p/q; z: charge of a metal ion), rather than the total charge of the complex, zq–p, is essential for the interactions between the hydroxo complexes and solvent molecules.
Mechanism of Base Catalyzed Oxidation of 2-(1-Hydroxyalkyl)thiazolium Ion with 3-Methyllumiflavin
Authors: Yano Yumihiko , Tamura Yoshiharu , Hoshino Yutaka , Tagaki Waichiro 
Published: July 2006

Abstract
The oxidation of 2-(α-hydroxybenzyl)- and 2-(1-hydroxyethyl)thiazolium ions with 3-methyllumiflavin was studied kinetically in an aqueous buffer solution. The results indicate that the rate-determining step is carbanion formation followed by rapid oxidation. The carbanion formation was subjected to general base catalysis.
The Effect of Sugars on the Thermal Denaturation of Lysozyme
Authors: Uedaira Hatsuho , Uedaira Hisashi 
Published: July 2006

Abstract
Thermal denaturation of lysozyme (hen egg-white) in aqueous sugar solution was studied by DSC measurements at pH 5 and by CD measurements at pH 2.12. All of the sugars investigated show a stabilizing influence on the native conformation. The effect of sugars on the transition temperature of lysozyme almost linearly increased with the increase of the numbers of equatorial hydroxyl groups per molecule of sugars. The ellipticity of the solutions at 294 nm of lysozyme and glucose or arabinose was additive in the value of each component at pH 5. The effect of sugars in stabilizing the protein structure may be due to the intensification of the hydrophobic interactions inside the protein molecule.
Fluctuation of Local Field and Depolarization Degree of the ν1 Line of Carbon Tetrachloride
Authors: Hyodo Shi-aki , Fujiyama Tsunetake 
Published: July 2006

Abstract
The depolarization degree of a molecule having a Td symmetry was expressed in terms of the mean square fluctuation of the local field which is felt by a molecule in the condensed phase. By the use of the mean square amplitude values observed by the X-ray diffraction method, the depolarization degree of liquid carbon tetrachloride was calculated to be 0.0021, which agrees well with the observed value of 0.0039±0.0002.
Study of Triplet-Triplet Energy Transfer between Like Molecules in a Rigid Glass Solution by Means of Optical Detection of Magnetic Resonance
Authors: Inoue Akinori , Nishi Nobuyuki , Kinoshita Minoru , Ebara Nozomu 
Published: July 2006

Abstract
The triplet-triplet energy transfer between like molecules was investigated for the system of quinoxaline in ethanol by using the method of optical detection of zero-field magnetic resonance at 1.4 K. The concentration dependence of the spin state population indicates that the energy transfer between quinoxaline molecules takes place at concentrations higher than about 2×10−2 mol/dm3.
Electronic Structure of Transition Metal Complexes II. Trans Influence in Ammine Complexes of the First Transition Metals
Authors: Kai Eiko , Misawa Tomoko , Nishimoto Kichisuke 
Published: July 2006

Abstract
CNDO/2 calculations of pentaammine complexes, [M(NH3)5X] (both low and high spin states), where M=Co2+, Co3+, Fe2+, and Fe3+, and X=FH, OH2, CO, NH3, pyridine, OH−, F−, and CN−, have been carried out in order to investigate the mutual influence between ligands. The present calculation shows that the σ-type mutual influence is remarkably affected by the oxidation number and the spin state of the metal ion and scarecely affected by the number of d electron (d electron configuration). Furthermore, the calculated results show the metal-ligand bond distance of a complex in the low spin state should be shorter than that in the high spin state.
Liquid Crystalline Properties of N-(4-Alkoxybenzylidene)-4-halogenoanilines
Authors: Sakagami Sakumitsu , Nakamizo Minoru 
Published: July 2006

Abstract
N-(4-Alkoxybenzylidene)-4-halogenoanilines have been synthesized, and the phase transitions determined using a differential scanning calorimeter and a polarizing microscope. Smectic and nematic phases have been observed for fluoro and chloro derivatives whereas bromo and iodo derivatives exhibit only a smectic phase.
Synthetic Photochemistry. XVIII. A Sensitizer Dependence in the Photooxidation of Indene and Acenaphthylene. The Occurrence of cis-1,2-Glycol Formation in a Rose Bengal-sensitized Reaction
Authors: Hatsui Toshihide , Takeshita Hitoshi 
Published: July 2006

Abstract
Upon Rose Bengal-sensitized photooxygenation, indene and acenaphthylene afforded substantial amounts of the expected cis-glycols by means of the reduction of the intermediate dioxetanes. The formerly proposed structure of one of the isomeric methoxy hydroperoxides was revised on the basis of the chemical and spectral evidence.
Background Atmospheric Concentrations of Halogenated Hydrocarbons in Japan
Authors: Makide Yoshihiro , Kanai Yutaka , Tominaga Takeshi 
Published: July 2006

Abstract
The atmospheric concentrations of CCl2F2, CCl3F, CH3CCl3, CCl4 CCl2FCClF2, CHCl=CCl3, CCl4, CHCl=CCl2, and CCl2=CCl2 in remote areas in Japan arid over the Japan Sea were measured in the summer of 1979. The averaged observed concentrations (in 10−12 v/v) for the compounds were 301±12, 175±7, 23±2, 117±11, 107±6, 14±10, and 19±10 respectively.
Induced Circular Dichroism Spectra of Some Racemic cis-Bis(ethylenediamine)cobalt(III) Complexes in Aqueous (R,R)-Tartrate and (R,R)-Tartratoantimonate(III) Solutions and Their Optical Resolution by Ion-exchange Chromatography
Authors: Nakazawa Hiroshi , Oh Chang Eon , Miyoshi Katsuhiko , Yoneda Hayami 
Published: July 2006

Abstract
Induced circular dichroism (induced CD) was measured for some racemic cobalt(III) complexes in aqueous (R,R)-tartrate and (R,R)-tartratoantimonate(III) solutions, and correlation was examined between the sign of their induced CD spectra and their elution order in ion-exchange chromatography.
Thermal Decomposition of Graphite Fluoride. I. Decomposition Products of Graphite Fluoride, (CF)n in a Vacuum
Authors: Watanabe Nobuatsu , Koyama Satoshi , Imoto Hiroki 
Published: July 2006

Abstract
The mechanism of thermal decomposition of graphite fluoride, (CF)n in a vacuum was studied by means of chemical and gas analyses, and the measurement of crystallinity. The crystallinity of (CF)n was slightly improved in the step of initial decomposition. The fluorine/carbon atomic ratio of initial gaseous product evolved by decomposition was about 2. The product is CF2 or C2F4, and then it gives several compounds by secondary reaction. Every second layers of (CF)n are decomposed, and the evolved molecules or radicals abstract fluorine atoms which are bonded to the neighboring two layers.
Intrinsic Quantum Efficiencies of Semiconductor Photoelectrodes Obtained by Temperature Measurement
Authors: Fujishima Akira , Maeda Yasuhisa , Honda Kenichi 
Published: July 2006

Abstract
Quantum efficiencies of photoelectrochemical reactions on n-type and p-type semiconductor electrodes can easily be determined by the measurement of temperature changes of the surface of semiconductor electrodes by use of thermistors. The quantum efficiencies are intrinsic, since only the absorbed light quanta contribute to temperature change. The merits of the method, simplicity and applicability to the semiconductor of large surface reflectance, are discussed. The intrinsic quantum efficiencies were compared with those obtained by the usual chemical actinometric method.
Liposomal Membranes. IV. Fusion of Liposomal Membranes Induced by Several Lipophilic Agents
Authors: Sunamoto Junzo , Hamada Tomiko , Murase Hiroki 
Published: July 2006

Abstract
It was found that several lipophilic agents, such as cis-, trans-ethyl decaprenoate and their structural analogues, significantly induce the liposome-liposome fusion when incubated together a set of two different liposomes, the A-liposome containing a marker and the B-liposome involving a lipophilic agent. The rate and extent of fusion were followed spectrophotometrically by monitoring the leakage of an amphiphilic marker, Bromothymol Blue, from the fused liposomes. Fusion was also visualized directly by electronmicrographic technique. When only A-liposome was incubated or when a blank liposome containing no lipophilic agents was added to the A-liposome after the preincubation, neither the fusion nor the marker release was observed at least in periods of several hours. Also, neither fusion nor the marker release was observed when either A- or Bliposome or both were multicompart-ment liposome. Removing cholesterol from liposome significantly depressed the fusion. The effect of cholesterol was more prominent on the A-liposome side. trans-Ethyl decaprenoate was more effective about three-fold to induce the fusion than the cis-isomer. Interestingly, the effect was parallel to the antihypertensive activity of the agent.
The Structure of the Cyclodextrin Complex. IX. The Crystal Structure of α-Cyclodextrin–m-Nitroaniline (1:1) Hexahydrate Complex
Authors: Harata Kazuaki 
Published: July 2006

Abstract
The crystal structure of α-cyclodextrin–m-nitroaniline hexahydrate complex was determined by X-ray analysis. The crystal is monoclinic and the space group is P21 with Z=2. The cell dimensions are: a=8.054(1), b=13.508(1), c=25.331(2) Å, and β=103.90(1)°. The structure was solved by an inspection of a Patterson map and by a trialand-error method. The refinement was done by the block-diagonal least-squares method to the final R-value of 0.11 for 2351 reflections (sinθ⁄λ&lt;0.49). α-Cyclodextrin molecules are stacked along the a axis in the head-to-tail fashion to form a channel-type structure. Most of the primary hydroxyl groups of α-cyclodextrin are in a gauche-gauche conformation and linked by hydrogen bonds directly or through water molecules to the secondary hydroxyl groups of the next α-cyclodextrin molecule along the channel. The guest m-nitroaniline molecules are linearly arranged in the channel. The α-cyclodextrin ring includes the nitrophenyl group, while the amino group protrudes outside from the secondary hydroxyl side of α-cyclodextrin and is hydrogen-bonded to a primary hydroxyl group of the next α-cyclodextrin molecule. Along the channel, m-nitroaniline molecules are linked to each other by a weak N–H···O hydrogen bond between the amino group and the nitro group. Columns formed by the stack of α-cyclodextrin are closely packed in the crystal, and intermolecular spaces are filled with water molecules which form many hydrogen bonds with each other and with α-cyclodextrin.
X-Ray Diffraction Study of Liquid Water
Authors: Nishikawa Keiko , Kitagawa Nobuko 
Published: July 2006

Abstract
The energy-dispersive X-ray diffractometer has been applied to the structural study of liquid water. The intensity data are in good agreement with those obtained by the use of an angle-dispersive method. Water has a structural correlation up to only 8 Å at 25 °C.
The Electrochemical Studies of Tetrasulfur Tetranitride in Acetonitrile
Authors: Hojo Masashi 
Published: July 2006

Abstract
S4(NH)4 has been prepared in a good yield (80% or more) by the electrolytic reduction (4-electrons) of S4N4 in the presence of a proton donor in acetonitrile. In the proton donor, a fairly high acidity (acetic acid or a stronger acid) and a much higher concentration than would be expected from the stoichiometry was needed. With a low acidity (e.g., phenol) or a low concentration of the proton donor, a side reaction occurred with the formation of H2S and NH3. Under these conditions, a blue species was produced in the course of the electrolysis; this species was confirmed to be S3−. The re-oxidation of S4(NH)4, the oxidation of S4N4, and the reduction of S4(NH)4 were also examined in this connection.