bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adsorption Effects of Highly Polarizable Organic Compounds on Electrode Kinetics
Authors: Ikeda Osamu , Watanabe Ken-ichi , Taniguchi Yasuhiko , Tamura Hideo 
Published: July 2006

Abstract
Adsorption effects of ureas and thioureas on electrode kinetics were studied by using the electrode reactions of Zn2+/Zn(Hg) and Eu3+/Eu2+. The standard rate constant for Zn2+/Zn(Hg) is controlled by the inner-layer permittivity. The effect of this permittivity has been explained in terms of the solvent reorganization energy. The effect of the adsorbates on the electrode kinetics of Eu3+/Eu2+ cannot be explained in terms of the inner-layer permittivity. These two results suggest different locations for the formation of the activated complex: Inside the adsorption layer for Zn2+ and just outside layer for Eu3+.
Interactions of Excited Lithium Atom with Molecular Hydrogen. II. Properties of Wave Functions in the Potential Crossing Region
Authors: Mizutani Kimiko , Yano Takakazu , Sekiguchi Atsushi , Hayashi Kazuko , Matsumoto Shiro 
Published: July 2006

Abstract
To elucidate the electronic mechanism of the quenching of electronically excited Li atoms by H2 molecules, CASSCF calculations were made regarding the Li–H2 system with various geometries. Special attention was payed to the electronic structure of the system in the crossing, or pseudocrossing, region of the potential energy surfaces. Simple CASSCF functions do not have a satisfactory spacial symmetry when the upper and the lower states are almost degenerate in energy, and need to be refined by the addition of a nonorthogonal CI. In the crossing region, electron density maps have shown that the Li atom is bonded more strongly to the nearer H atom than to the farther H atom in the ground state, whereas the opposite is the case for an excited state. Such properties of the wave function lead naturally to a picture of a nonadiabatic process occurring in the crossing region. The pseudocrossing of the first excited and the ground state potential energy surfaces has also been found for all geometries midway between the C2v and C∞v symmetries.
Colloid Chemical Studies on the Aggregation of Phospholipid Vesicles with Metal Cations
Authors: Furusawa Kunio , Kakoki Hiroyuki , Matsumura Hideo 
Published: July 2006

Abstract
Aggregation behavior of phosphatidylethanolamine (PE) and Phosphatidylserine (PS) vesicles that have resulted with various metal cations, has been studied to determine their adsorption characteristics. The critical flocculation concentration of these cations for both vesicles was determined by two techniques, i.e., by the kinetic method in which the rate of flocculation was measured turbidimetrically, and by the traditional static method. The results have been analysed by the usual stability concept in the colloid chemistry, and these analyses revealed that there are two mechanisms in the vesicle aggregation. One is the charge neutralization of the polar groups on the vesicle surface, which is induced by the adsorption of multivalent cations (Th4+, La3+), and the other is the interparticle binding (or the interparticle bridging) caused by the divalent cations (Ca2+, Mg2+).
Stability Constants of Scandium Complexes. II. Dicarboxylate Complexes Species
Authors: Itoh Hisako , Ikegami Yukihiro , Suzuki Yasuo 
Published: July 2006

Abstract
The stability constants of scandium complexes with malonate, maleate, itaconate, glutarate, adipate, and succinate ligands were determined titrimetrically at 25.0 °C and at an ionic strength of 0.1. The chelate effect was negligible for the stability of the scandium complexes with the dicarboxylate ligands studied in contrast with the lanthanoid complexes. The complex formation of scandium might be explained by an electrostatic ionic bond similar to ones exhibited in the lighter rare-earth complexes, due to linear relationships between the stability constants and the ionic potential Z2⁄r.
Oxidative Coupling of 1-(2,6-Dichlorobenzoyl)pyrroles and -pyrazoles and Alkyl Acrylates by Palladium(II) Acetate
Authors: Itahara Toshio , Kawasaki Kazukuni , Ouseto Fumio 
Published: July 2006

Abstract
Treatments of 1-(2,6-dichlorobenzoyl)-, 3-acetyl-1-(2,6-dichlorobenzoyl)-, 1-(2,6-dichlorobenzoyl)-2-formyl-, and 1-(phenylsulfonyl)pyrroles with palladium acetate and alkyl acrylates gave the corresponding α-alkenyl-substituted pyrroles in good yields, while the reaction of 1-(2,6-dichlorobenzoyl)-2,5-dimethylpyrrole gave small amounts of β-alkenyl-substituted pyrroles. Under similar conditions, 1-(2,6-dichlorobenzoyl)pyrazole and 1-(2,6-dichlorobenzoyl)-3,5-dimethylpyrazole reacted with palladium acetate and alkyl acrylates to give the corresponding 4-alkenyl-substituted pyrazoles. The reaction of 1-(2,6-dichlorobenzoyl)-4-methylpyrazole gave 5-alkenyl-substituted pyrazole
Exponential Distribution of Aqueous 1–1 Electrolytes Due to Convective Thermal Diffusion in Vertical Columns
Authors: Takeyama Naokata , Nakashima Kimie 
Published: July 2006

Abstract
Using titanium columns of 10 cm length and glass columns of different lengths, the vertical exponential distribution of the concentration of aqueous 1–1 electrolytes in each column has been ascertained at the steady state of convective thermal diffusion. The value of(a4⁄L) In q is found to be characteristic of individual solutes, and possibly proportional to the thermal diffusion coefficients, where q is the quotient of the steady concentration of a solute at the bottom of column to that at the top, L is the effective column length, and a is the working column space. This fact has been also shown by jointed glass columns with and without top vessel, capable of multistep sampling from the top to the bottom through intermediate jointed parts along columns. The rate constants in processes to the steady state have been examined to be proportional to the square of temperature difference applied, and to decrease with increasing L. Although the enhancement of downward enrichment of solutes has been observed by attaching a large top vessel to the column top, the rate constants decrease inevitably and significantly thereby.
7-Diazo-7H-benz[de]anthracene and 7H-Benz[de]anthracen-7-ylidene
Authors: Izuoka Akira , Murata Shigeru , Iwamura Hiizu 
Published: July 2006

Abstract
7-Diazo-7H-benz[de]anthracene has been prepared by the HgO oxidation of the corresponding hydrazone in ether. The yellow-green diazo compound in a 2-methyltetrahydrofuran matrix has been photolyzed with a high-pressure mercury lamp in an ESR cavity at 14 K. From the X, Y, and Z transitions due to the unoriented triplet species, the zero-field splitting parameters of 7H-benz[de]anthracen-7-ylidene have been determined: |D|=0.2662 and |E|=0.0175 cm−1. A temperature dependence experiment showed linear signal intensities vs. 1⁄T plots, indicating that the carbene is in the ground triplet state. The zero-field splitting parameters have been theoretically calculated by assuming the dipolar interaction of the electron spins one on the n-orbital at the 7-position and the other delocalized on the Hückel π-framework.
Photoelectron Angular Distribution for Jahn-Teller Split Bands of Some Molecules in VUV Photoelectron Spectroscopy
Authors: Shiromaru Haruo , Katsumata Shunji 
Published: July 2006

Abstract
Measurements of photoelectron angular distribution were carried out with NeI and HeI resonance lines for Jahn-Teller split bands of methane, ethane, cyclopropane, neopentane, tetramethylsilane, carbon tetrachloride, and ammonia. The variation of an asymmetry parameter β across the band is presented. Significant β variations across the Jahn-Teller split bands due to the l2T2 states of C(CH3)4+ and CCl4+ could not be explained in terms of photoelectron energy dependence of β. These abnormal variations will be discussed on the basis of characteristics of the degenerate molecular orbitals split by the Jahn-Teller effect.
Variational Determination of Molecular Orbital Energies in Independent Particle Models
Authors: Isihara Makoto 
Published: July 2006

Abstract
A simple construction formalism of molecular orbitals is presented in the context of partitioning of the electronic Hamiltonian. As a consequence of the formalism, a variational method of determining molecular orbital energies is proposed. The method is illustrated with the numerical example for the helium atom, whose result is reasonably meaningful.
Binding of 1-Decylpyridinium Bromide to Poly(vinyl sulfate)
Authors: Shirahama Keishiro , Tashiro Masatoshi 
Published: July 2006

Abstract
Binding of 1-decylpyridinium bromide onto poly(vinyl sulfate) in aqueous solution is measured by using a potentiometric titration method which employs propionyl-α-cyclodextrin as a neutral carrier in a 1-decylpyridinium selective electrode. Binding is highly cooperative and biphasic. The first step binding is reduced, while the second one increased on increasing added NaBr concentration. Temperaure dependence is very small giving an enthalpy of binding equal to −1.4 kJ mol−1.
Synthesis of Azobenzo-crown Ethers and Their Complexation Behavior with Metal Ions
Authors: Shiga Masanobu , Nakamura Hiroshi , Takagi Makoto , Ueno Keihei 
Published: July 2006

Abstract
New crown ethers which have a benzeneazo group as a building block of a macrocyclic polyether ring. The complexation properties of these new azobenzo-crown ethers with alkali and alkaline earth metal iodide salts were investigated in acetonitrile solution spectrophotometrically. The complex formation constants were evaluated for alkali metal salts. The azo group is not particularly a favorable component of a crown ether macrocycle for stabilizing the metal complexes.
Synthesis of N-Tripeptidyl-d-glucosamine by the Stepwise Reaction of N-Carboxy α-Amino Acid Anhydride
Authors: Oya Masanao , Negishi Toshiyuki 
Published: July 2006

Abstract
N-Peptidyl-d-glucosamines were synthesized by the stepwise reaction of N-carboxy α-amino acid anhydrides (4-alkyl-2,5-oxazolidinediones) with d-glucosamine hydrochloride in the presence of equimolar sodium methoxide in a mixture of acetonitrile and methanol, or in methanol, at a low temperature. Polymerization reaction of N-carboxy α-amino acid anhydrides (NCAs) did not occur at −50 °C. The mechanism of the reaction was then studied.
NAD(P)+–NAD(P)H Model. 47. Mechanism of the Formation of 1,4-Dihydronicotinamide in the Reaction of Pyridinium Salt and Amine
Authors: Ohno Atsuyoshi , Ushida Satoshi , Oka Shinzaburo 
Published: July 2006

Abstract
An amine reduces 1-benzyl-3-carbamoylpyridinium ion (BNA+) into 1-benzyl-1,4-dihydronicotinamide (BNAH) in aqueous solution. The mechanism of reduction has been elucidated. The covalently bound adduct of the amine and BNA+ at the 6-position is found to be the true reductant. The reduction with formate proceeds through the direct “hydride-transfer” mechanism. Selectivity of nucleophilic attack on the 4- and 6-positions of BNA+ is discussed in terms of hard-soft-acid-base (HSAB) principle.
Mössbauer Effect of 119Sn in Tin Sulfides Produced through Thermal Decomposition of SnS2
Authors: Ichiba Sumio , Kunita Kazushi 
Published: July 2006

Abstract
The intermediate tin sulfides produced through thermal decomposition of SnS2 were studied by quenching and Mössbauer spectroscopy. The thermal decomposition of SnS2 in a nitrogen gas flow proceeded to SnS via Sn2S3. The existing phases of the decomposition products in the range of the S/Sn ratio less than 1.50 were Sn2S3 and Sn1−xS. A new peak observed in the Mössbauer spectrum of tin sulfides with the S/Sn ratio less than 1.04 was assigned to Sn4+ in the nonstoichiometric compound Sn1−xS.
Kinetics of Ligand Substitution Reaction between Cyanide Ion and NiL2 (L=4-(2-Pyridylazo)resorcinol, Diethylenetriamine, and Ethylenediamine)
Authors: Bajaj Hari Chand , Phull Madhu , Nigam Prem Chandra 
Published: July 2006

Abstract
The kinetics of substitution reaction of cyanide ion with some bis complexes [NiL2]2−2n, where Ln− is 4-(2-pyridylazo)resorcinolate, diethylenetriamine, or ethylenediamine, to form the square planar complex [Ni(CN)4]2− has been studied spectrophotometrically in aqueous solutions. The rate expression has the form:rate={kdNiL2+k′[CN−]}[NiL22−2n], where k′ is a composite rate constant in case of par and dien and is equal to kCNNiL2 in case of en. These results indicate that these bis complexes are not directly converted into [Ni(CN)4]2− but first lose one ligand molecule and cyanide assists this loss. The backward reaction between [Ni(CN)4]2− and L is first order in each reactant and inverse first order in cyanide. Though the mechanism for the reactions appears to be same, there are kinetic differences in the behaviour of en and the other two chelates. The rate determining step for the three reactions have been identified. The activation parameters for the forward reaction have been evaluated to support the proposed mechanism. The temperature dependence of backward reaction has also been given.
Behavior of Amine in Rhodium Complex–Tertiary Amine Catalyst System Active for Hydrogenation of Aldehyde under Oxo Reaction Conditions
Authors: Mizoroki Tsutomu , Kioka Mamoru , Suzuki Masayasu , Sakatani Shiro , Okumura Atsushi , Maruya Ken-ichi 
Published: July 2006

Abstract
The title reaction was investigated to elucidate the reported disagreements on the kinetics. The concentration and the coordination stability of amine were found to affect the optimum pressure of carbon monoxide and the kinetics, and were suggested to control the reaction mechanism.
Catalytic Effects of Chlorate Ions on the Electrode Reaction Processes of 12-Molybdophosphate and 12-Molybdosilicate
Authors: Unoura Kei , Iwashita Atuko , Itabashi Eiki , Tanaka Nobuyuki 
Published: July 2006

Abstract
The third cathodic waves corresponding to the reduction processes from the four-electron to the six-electron reduction products of both 12-molybdophosphate and 12-molybdosilicate are catalytic in nature in the presence of chlorate ions. The six-electron reduction product of 12-molybdophosphate is oxidized by chlorate ions more rapidly than that of 12-molybdosilicate.
Ozonation of Xanthene
Authors: Matsui Masaki , Miyamoto Yoshihiko , Shibata Katsuyoshi , Takase Yoshimi 
Published: July 2006

Abstract
The ozonation of xanthene was studied using an oxygen stream. Ozone attacks the methylene group of xanthene via a 1,3-dipolar insertion reaction to give the hydrotrioxide intermediate, followed by a loss of singlet oxygen to form xanthydrol. The ozonation of xanthydrol gave singlet oxygen, water and xanthone accompanied by autoxidation.
Electrochemical Carboxylation of α,β-Unsaturated Ketones with Carbon Dioxide
Authors: Harada Junji , Sakakibara Yoshihisa , Kunai Atsutaka , Sasaki Kazuo 
Published: July 2006

Abstract
Several aromatic and aliphatic α,β-unsaturated ketones were converted to the corresponding γ-keto acids by the electrochemical reduction in acetonitrile in the presence of CO2. The yields of the keto acid were 73–82% when the enones have at least one aromatic substituent. In the case of aliphatic enones, the yields of the carboxylation reaction were 67% for 2-cyclohexen-1-one and 44% for 3-buten-2-one.
Generation and Reactions of 5,6-Dimethylene-2-cyclohexene-1,4-diones. A New Synthesis of Polycyclic 1,4-Benzoquinones
Authors: Kanao Yoshinori , Oda Masaji 
Published: July 2006

Abstract
1,2,3,6-Tetrahydrobenzocyclobutene-3,6-dione underwent thermal ring opening of the four-membered ring at 140°C to generate 5,6-dimethylene-2-cyclohexene-1,4-dione. This is a highly reactive substance and was trapped as dimers or Diels-Alder adducts giving polycyclic 1,4-benzoquinones. Intramolecular rearrangements preferably took place in some derivatves.
The Intermolecular Interaction of Tetrathiafulvalene and Bis(ethylenedithio)tetrathiafulvalene in Organic Metals. Calculation of Orbital Overlaps and Models of Energy-band Structures
Authors: Mori Takehiko , Kobayashi Akiko , Sasaki Yukiyoshi , Kobayashi Hayao , Saito Gunzi , Inokuchi Hiroo 
Published: July 2006

Abstract
Based on the extended Hückel molecular orbital calculations, the relation between the anisotropy of the band structure and the arrangement of the organic molecules is investigated for two organic donors, tetrathiafulvalene (TTF) and bis(ethylenedithio)tetrathiafulvalene (BEDT–TTF). The intermolecular overlaps of their HOMO are calculated while the intermolecular arrangements are varied. The maps of the overlaps thus obtained are then used to estimate the band-structure parameters of (TMTTF)2X and (BEDT–TTF)2ClO4(C2H3Cl3)0.5. The Fermi surface of (TMTTF)2X is quasi-one-dimensional and not closed. On the contrary, (BEDT–TTF)2ClO4(C2H3Cl3)0.5 is regarded as a two-dimensional semimetal.
Electrical Relaxations in Mixtures of Lithium Chloride and Glycerol
Authors: Howell F Scott , Moynihan Cornelius T , Macedo Pedro B 
Published: July 2006

Abstract
The dielectric constant ε′ and the electrical conductivity σ were measured as a function of frequency (0.1–2 MHz) and temperature for an electrolyte-polar solvent system: lithium chloride in glycerol. Mole fractions of LiCl were 0, 1, 2, 5, 10, 20, and 33.3%. Data were analysed in terms of an inverse complex permittivity(electrical modulus). At lower mole fractions, two separate modulus relaxations were observed, one due to the ionic diffusion and the other to the dipole reorientation. These two relaxation processes converged with increasing LiCl mole fraction and were not distinguishable at 20%. The moduli isotherms at 33.3% were characteristic of a fused salt. Average relaxation times and distributions for both processes were determined by computer fits to a Gaussian distribution in the logarithms of these times. Their temperature and mole fraction dependences are discussed. The conductivity relaxations became slightly broader than single at 10%; this shows the influence of the charge concentration on the structural relaxation process.
Volume and Adiabatic Compressibility of Amino Acids in Urea–Water Mixtures
Authors: Ogawa Toshio , Yasuda Motoo , Mizutani Kiyoshi 
Published: July 2006

Abstract
Apparent molal volumes (φV) and apparent molal adiabatic compressibilities (φKS) at 25 °C have been obtained for the following amino acids in water and in urea-water mixtures (up to 8 mol kg−1 urea for φV and at 3 mol kg−1 for φKS) from measurements of density and ultrasonic velocity: glycine, l-alanine, β-alanine, α-aminoisobutyric acid, l-valine, l-serine, and l-threonine. The limiting values φVo and φKSo were calculated by a linear extrapolation using the least-squares method. These data were used to derive the volumes of transfer and the adiabatic compressibilities of transfer of the amino acids from water to aqueous urea solutions. Both of these transfer functions were positive. The results were interpreted in terms of structure-breaking interaction of urea upon water.
Preparation of Graphite Fluoride by Vertical Vibrating Reactor
Authors: Watanabe Nobuatsu , Katoh Saburo , Nakajima Tsuyoshi 
Published: July 2006

Abstract
A study was made of the yield and crystallinity of graphite fluoride using a vertical vibrating reactor, which made it possible to prepare much graphite fluoride. The yield of graphite fluoride decreased beyond 500 °C for natural graphite and petroleum coke heat-treated at 2800 °C, and beyond 300 °C for calcined petroleum coke. The crystallinity of graphite fluoride was improved through the decomposition and refluorination process in these temperature ranges where the yield decreased. It was found that a sublimative solid by-product was formed together with gaseous fluorocarbons. It was a white solid fluorocarbon with 5–9 cyclohexane rings.
Indole Syntheses Utilizing o-Methylphenyl Isocyanides
Authors: Ito Yoshihiko , Kobayashi Kazuhiro , Seko Norihiko , Saegusa Takeo 
Published: July 2006

Abstract
New indole synthesis starting with o-methylphenyl isocyanides such as o-tolyl, 2,4-xylyl, and 2,6-xylyl isocyanide is described in full detail. Treatment of o-tolyl isocyanide with LDA in diglyme at −78 °C generated selectively o-(lithiomethyl)phenyl isocyanide in an almost quantitative yield, which on warming up to room temperature was cyclized to indole after aqueous workup. Similary, 2,4-xylyl and 2,6-xylyl isocyanides were cyclized to 5-methylindole and 7-methylindole quantitatively. The o-(lithiomethyl)phenyl isocyanides reacted with electrophiles such as alkyl halides and alkylene oxides to give o-alkylphenyl isocyanides, which were cyclized via the lithiation at the orthobenzylic carbon to afford 3-substituted indoles. On the other hand, the o-(lithiomethyl)phenyl isocyanides generated in situ at −78 °C was first warmed up to room temperature and then treated with electrophiles to furnish 1-substituted indoles. The o-(lithiomethyl)phenyl isocyanides were acylated in a fairly good yield with N-acylaziridines to give o-(acylmethyl)phenyl isocyanides, which were readily alkylated in the presence of sodium hydride to produce o-(1-acylalkyl)phenyl isocyanides. On acid hydrolysis followed by neutralization, o-(1-acylalkyl)phenyl isocyanides were converted to 2,3-disubstituted indoles.
The Synthesis of Coleon B Tri-O-methyl Ether
Authors: Matsumoto Takashi , Imai Sachihiko , Nishizaki Katsumi , Kurihara Fumio , Goto Fumitaka 
Published: July 2006

Abstract
Methyl (+)-12-benzoyloxy-11,14-dioxo-8,12-abietadien-18-oate was converted into methyl 11,12,14-trimethoxy-8,11,13-abietatrien-18-oate (8). The Grignard reaction of 8 with phenylmagnesium bromide, followed by oxidation with lead tetraacetate, afforded 11,12,14-trimethoxy-19-norabieta-4(18),8,11,13-tetraene. This was then converted into 3α-bromo-11,12,14-trimethoxy-18-norabieta-8,11,13-trien-2-one (15) by a series of reactions: selenium dioxide oxidation, catalytic hydrogenation, dehydration, hydroxybromination, and Jones oxidation. Acetalization of 15 with 1,2-ethanediol, followed by oxidation with Jones reagent and then with oxygen in the presence of potassium t-butoxide, afforded 3-bromo-2,2-ethylenedioxy-6-hydroxy-11,12,14-tri-methoxy-18-norabieta-5,8,11,13-tetraen-7-one, which was converted into (−)-coleon B tri-O-methyl ether (4) by hydrolysis and dehydrobromination. Another conversion of 15 into 4 was also achieved by a series of reactions: debromination, acetalization, Collins oxidation, oxygen oxidation, hydrolysis, and dehydrogenation.
Preparation and Crystal Structure of Bis[(2-aminoethyl)dimethylphosphine][1,2-bis(dimethylphosphino)ethane]cobalt(III) Tribromide Dihydrate, [Co{NH2CH2CH2P(CH3)2}2-{(CH3)2PCH2CH2P(CH3)2}]Br3·2H2O
Authors: Ohishi Tomoji , Ohba Shigeru , Kashiwabara Kazuo , Saito Yoshihiko , Fujita Junnosuke 
Published: July 2006

Abstract
The title compound has been prepared and the crystal structure determined by the X-ray diffraction method. The complex ion is the trans(P, N) isomer, where one of the N atoms of (2-aminoethyl)dimethylphosphine (edmp) occupies the position trans to the P atom of the other edmp ligand.
Synthesis of 1,2-Polymethyleneimidazoles Utilizing Intramolecular Ring Transformation
Authors: Sasaki Tadashi , Ohno Masatomi , Ito Eikoh 
Published: July 2006

Abstract
Among the intramolecular cyclodehydration of 2-(β-, δ-, and ε-aminoalkyl)oxazoles, 2-(δ-aminoalkyl)oxazoles afforded the desired 1,2-tetramethyleneimidazoles on pyrolysis, while 2-(β- and ε-aminoalkyl)oxazoles unchanged under the same conditions.
Cycloaddition of Vinyl Isocyanate to 1,3-Dipoles
Authors: Ohshiro Yoshiki , Komatsu Mitsuo , Okamura Aiichiro , Agawa Toshio 
Published: July 2006

Abstract
1,2-Cycloadditions of 3-methyl-1-(methylthio)-1-butenyl isocyanate with N-t-butyl-α-toluenimine N-oxide and with in situ-generated N-t-butyl-α-methyl-α-lactam afforded an oxadiazolidinone derivative and a hydantoin derivative in 100 and 46% yields, respectively.