bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of Scandium(III), Yttrium(III), and Some Lanthanoid(III) p-Toluenesulfonates, [Sc(C7H7SO3)2(H2O)4](C7H7SO3)·2H2O and [M(C7H7SO3)2(H2O)6](C7H7SO3)·3H2O (M=Y, Sm, Gd, Dy, Ho, Er, Yb); and Yttrium(III) and Dysprosium(III) 2-Naphthalenesulfonates, [M(C10H7SO3)2(H2O)6](C10H7SO3)·3H2O (M=Y, Dy)
Authors: Ohki Yoshiyuki , Suzuki Yasuo , Takeuchi Toshio , Ouchi Akira 
Published: July 2006

Abstract
Scandium(III) p-toluenesulfonate hexahydrate, as well as the isomorphous yttrium(III) and six lanthanoid(III) (Sm, Gd, Dy, Ho, Er, and Yb) p-toluenesulfonate enneahydrates, were synthesized and their structures were determined by the single-crystal X-ray diffraction technique. The scandium salt was monoclinic with the space group P21⁄a, Z=4 (the cell constants were a=23.672(16), b=15.792(6), c=7.7543(12) Å, β=92.86(3)°, and the final R value was 0.059). The central metal atom is hexa-coordinated, being in an octahedral geometry, in which two unidentate sulfonate oxygen atoms (in cis-configuration) and four water oxygen atoms are ligated. The latter seven salts were also monoclinic with a space group of P21⁄n, and Z=4 (the cell constants of the holmium salt, for example, were a=25.058(19), b=7.476(2), c=17.802(10) Å, β=98.80(8)°, and its final R value was 0.039). The central metal atom of these complexes are octa-coordinated, being in a square-antiprism geometry in which two unidentate sulfonate and six water oxygen atoms are ligated. In both types of complexes, no ligand bridgings were found, and one in three sulfonate ions was not coordinated to the metal atom. In the respective lanthanoid(III) complexes, M–O(sulfonato) bonds are shorter than the M–O(water) ones. The corresponding M–O bonds of the respective complexes decrease, almost proportional to the sum of the Shannon’s ionic radii of the metal and oxygen, with the metal atomic numbers. Each M–O bond length of the yttrium(III) p-toluenesulfonate and 2-naphthalenesulfonate had the value expected from the corresponding bond lengths of the series of the respective isomorphous lanthanoid(III) salts, referring to its metal ionic radius.
Synthesis of Branched-Chain Oligosaccharides in Sarsasaponins by Dehydrative Glycosylation
Authors: Koto Shinkiti , Morishima Naohiko , Uchino Masaharu , Fukuda Misa , Yamazaki Masayo , Zen Shonosuke 
Published: July 2006

Abstract
The branched-chain oligosaccharides, 6-O-(β-d-glucopyranosyl)-4-O-(α-l-rhamnopyranosyl)-d-glucopyranose, and 2,6-di-O-β-d-glucopyranosyl)-4-O-(α-l-rhamnopyranosyl)-d-glucopyranose, which compose sarsasaponins, as well as the structurally related 2-O-(β-d-glucopyranosyl)-4-O-(α-l-rhamnopyranosyl)-d-glucopyranose were synthesized stepwise via dehydrative glycosylation by a ternary mixture of p-nitrobenzenesulfonyl chloride, silver triflate, and triethylamine.
A Michael Addition and Peterson Olefination Sequence Using 1-Silylethenyl Sulfides and Sulfoxide
Authors: Kanemasa Shuji , Kobayashi Hiroshi , Tanaka Junji , Tsuge Otohiko 
Published: July 2006

Abstract
Reaction of organolithiums with a 1-(trimethylsilyl)ethenyl sulfide produces 1,2-bis(trimethylsilyl)cyclopropanes, while use of 1-silylethenyl sulfides bearing a bulkier silyl moiety results in exclusive formation of the corresponding Michael adduct anions which are then quenched with aldehydes to give vinyl sulfides. On the contrary, a 1-(trimethylsilyl)ethenyl sulfoxide undergoes smooth Michael addition with a variety of organo-metallics and the resulting carbanion intermediates can be quenched with aldehydes to produce vinyl sulfoxides. Scope and limitations of these sequential reactions are discussed.
Generation of Sulfur-Functionalized Nitrile Oxide, (Phenylthio)acetonitrile Oxide, and Synthetic Applications
Authors: Kanemasa Shuji , Norisue Yasumasa , Suga Hiroyuki , Tsuge Otohiko 
Published: July 2006

Abstract
The first generation of a new sulfur-functionalized nitrile oxide 1,3-dipole, (phenylthio)acetonitrile oxide, is presented. Its cycloadditions to a variety of olefins and acetylenes lead to 3-(phenylthiomethyl)-2-isoxazolines and -oxazoles, the formers being selectively deprotonated at the carbon substituted by the sulfur moiety. The resulting sulfur-stabilized carbanions react with aldehydes, esteric Michael acceptors, and alkyl halides to enable the introduction of a carbon substituent to the side chain on 3-position. Raney Ni reduction of these 2-isoxazolines gives β,β′-dihydroxy ketones and β-hydroxy ketones.
Interaction of Poly[N-(3-aminopropyl)glycine] and Its Derivatives with Lipid Membrane
Authors: Yagi Yoshiko , Kimura Shunsaku , Imanishi Yukio 
Published: July 2006

Abstract
Poly[N-(3-aminopropyl)glycine] (PolyNAPGly, 5) and its derivatives were synthesized as model peptides of the membrane-bound enzymes, and investigated on their interactions with lipid membrane. PolyNAPGly (5) was shown to be distributed to dipalmitoylphosphatidyl choline bilayer membrane without destruction of the vesicle structure. Dodecyl groups were introduced to the side chains of PolyNAPGly (5), and found to facilitate binding of the polymer to lipid membrane. However, the introduction of the excess amount of hydrophobic groups to PolyNAPGly (5) caused the formation of polymer micelles, and the addition of such polymers to lipid vesicles destroyed the membrane structure. The derivative of PolyNAPGly (5) (n=35) bearing one or two dodecyl groups and some Nε-benzyloxycarbonylhistidyl groups was found to be bound tightly to lipid membrane without destruction of the membrane structure. The addition of these polypeptides to vesicles decreased the membrane fluidity.
Stereoselective Total Synthesis of (±)-Labdane-8α,15-diol and (±)-Eperuane-8β,15-diol
Authors: Hirota Hiroshi , Nakamura Toshio , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
(±)-Labdane-8α,15-diol and (±)-eperuane-8β,15-diol, diastereomeric diterpenes to each other, were prepared separately and stereoselectively, via a common 7-membered lactone from the known tricyclic keto alcohol.
A Convenient Method for the Preparation of Secondary Propargylic Ethers. The Reactions of Acetals with 1-Trimethylsilyl-1-alkynes Promoted by the Combined Use of Catalytic Amounts of Tin(IV) Chloride and Zinc Chloride
Authors: Hayashi Masaji , Inubushi Atsuro , Mukaiyama Teruaki 
Published: July 2006

Abstract
In the coexistence of catalytic amounts of SnCl4 and ZnCl2, acetals undergo a coupling with 1-trimethylsilylalkynes to give secondary propargylic ethers in good yields. Similarly, propargylic ethers are directly produced from aldehydes by the treatment with alkoxytrimethylsilanes and 1-trimethylsilylalkynes under the same conditions. This catalyst system also efficiently promotes aldol reaction of silyl enol ethers with acetals or aldehydes, and the Michael reaction of silyl enol ethers with α,β-unsaturated ketones.
ESR Studies of Copper(II) Ion Doped in Single Crystal of Benzo-15-crown-5 Complex
Authors: Li Yong , Tajima Kunihiko , Ishizu Kazuhiko , Azuma Nagao 
Published: July 2006

Abstract
Angular-dependent ESR measurements were carried out at 77 K for 65Cu(II) ions doped in a single crystal of benzo-15-crown-5 (B15C5) magnesium complex. Not only the allowed resonance lines of copper(II) ions, but also the forbidden lines arising from a nuclear quadrupole interaction were observed. Based on an analysis of the single crystal ESR spectra, the spin Hamiltonian containing the quadrupole term was determined for a B15C5–65Cu(II) complex having a 3dz2 ground state in a B15C5–Mg(II) solid matrix.
Bistability and Oscillations in the Bromate–Bromide–Cerium(III) System in Continuous-Flow Stirred Tank Reactor. A Simulation Using a New Set of Rate Constants of the FKN Scheme
Authors: Sasaki Yoshihiro 
Published: July 2006

Abstract
The bahavior of a bromate–bromide–cerium(III) system in a continuous-flow stirred tank reactor was simulated within the framework of the FKN reaction scheme and a new set of rate constants prepared by Field and Försterling. The characteristic properties such as bistability, hysteresis and minimal oscillations could be reproduced. In order to understand bistability in this system, the dynamic behavior of a four-variable model was examined by means of a two-variable approximation.
The Potentiometric Detection of Complex Formation between IgG and anti-IgG Using a Chemically Modified Tantalum Electrode
Authors: Tanaka Toshihiko , Yamamoto Naoto , Tsubomura Hiroshi 
Published: July 2006

Abstract
Tantalum electrodes were chemically modified with anti-IgG to detect IgG (immunoglobulin G) or with IgG to detect anti-IgG by using cyanuric bromide. Changes in the potential as a result of the antigen-antibody reaction can be explained by a simple first-order kinetics equation, while the polarity of the changes at various pH’s can be explained in terms of the charge transfer between anti-IgG and IgG in a way similar to that shown in previous reports for the case of Ti electrodes. The surface modification was confirmed by Auger Electron Spectroscopy (AES).
Redox-Linked Protonation of [Fe4X4(YR)4]2− (X,Y=S and Se; R=n-C12H25 and C6H4-p-t-Bu) in Aqueous Solutions
Authors: Nakamoto Masami , Tanaka Koji , Tanaka Toshio 
Published: July 2006

Abstract
A series of [Fe4X4(YR)4]2− (X,Y=S and Se; R=n-C12H25 and C6H4-p-t-Bu) were prepared as n-Bu4N+ salts. In aqueous Triton X-100 micellar solutions, only the reduced forms of [Fe4X4(YR)4]2− (X,Y=S and Se; R=n-C12H25 and C6H4-p-t-Bu) undergo protonation reactions at the sulfur or selenium atom of the Fe4X4 (X=S and Se) core to exist as an equilibrium mixture of the protonated and unprotonated clusters. On the other hand, not only the oxidized but also the reduced forms of [Fe4X4(YC6H4-p-t-Bu)4]2− (X,Y=S and Se) undergo protonation reactions in aqueous poly[2-(dimethylamino)hexanamide] (PDACA) solutions. The pKox values of [Fe4X4(YC6H4-p-t-Bu)4]2− (X,Y=S and Se) vary depending on the terminal thiolate and selenolate ligands; 5.9 for Y=S and 6.8 for Y=Se, whereas the pKred values of [Fe4X4(YC6H4-p-t-Bu)4]3− are controlled by the core sulfur and selenium; 8.8 for X=S and 7.3 for X=Se. Such characteristic pKox and pKred values suggest that the protonation takes place at the terminal sulfur or selenium atom of the oxidized clusters [Fe4X4(YC6H4-p-t-Bu)4]2− (X,Y=S and Se), while it occurs at the sulfur or selenium atom of the Fe4X4 core of the reduced clusters [Fe4X4(YC6H4-p-t-Bu)4]3− (X,Y=S and Se).
Ion–Solvent Interaction of Amino Acids. The Role of the “Zwitterionic” and the “Ionic” Forms in the Modification of Water Structure over the Temperature Range 25–45 °C
Authors: Bhattacharyya Moni Mohan , Sengupta Mihir 
Published: July 2006

Abstract
Viscosities and densities of aqueous glycine, glycinium chloride, sodium glycinate, betaine, betainium chloride [(CH3)3\overset+NCH2COOH·Cl−], and tetramethylammonium bromide solutions have been measured at 25, 30, and 40 °C over the concentration range 0.01 to 0.1 M. The sequence of the viscosity B-coefficient values obtained is in the order: Banion&gt;Bcation&gt;Bzwitterion for the glycine and betaine systems. The comparatively higher structure promoting behavior of the anion has been discussed in terms of the charge delocalization effect. Apparent molal volumes at infinite dilution have also been calculated, and the ratio B⁄φv° furnishes important information about the nature of solvation around the ion. The present study indicates that in the betaine molecule, the opposing nature of ion–water interaction at the two charge centers renders the system neither a “structure maker” nor a “breaker” in aqueous solution.
Kinetics of Reduction of Silver(II) by Sodium Tetrahydroborate
Authors: Dasgupta Manash , K. Mahanti Mahendra 
Published: July 2006

Abstract
The kinetics of reduction of silver(II) by sodium tetrahydroborate in aqueous acidic solution has been investigated. The reaction was observed to proceed in two steps, namely, (a) the formation of the intermediate AgI and (b) the subsequent conversion of AgI to Ag0. The activation parameters for the two steps have been separately calculated. The intermediate AgI species, and the final products, were characterized by chemical and spectral methods. A plausible mechanism for the reduction of AgII ions has been proposed.
Visible Light Assisted Heterogeneous Catalysis. Decomposition of Peroxomonosulfate over Doped and Undoped WO3 Dispersions in Aqueous Medium
Authors: Maruthamuthu Pichai , Ashokkumar Muthupandian , Venkatasubramanian Lakshmanan 
Published: July 2006

Abstract
Aqueous suspension of RuO2-loaded WO3 powder on illumination with light of λ≥410 nm was found to decompose peroxomonosulfate (PMS, HSO5−) efficiently. The rate and other kinetic parameters indicated that the decomposition process followed Langmuir kinetics; at low concentrations of HSO5− (0.54–2.06×10−3 mol dm−3) the reaction obeyed a first-order kinetics and at higher concentrations, ([HSO5−]&gt;3.00×10−3 mol dm−3) the rate became independent of [HSO5−]. The effects of pH and the molar percentage of the dopant on the rates were also investigated. Small amount of doping by RuO2 (2.5 molar percentage) was found to increase the photocatalytic decomposition of HSO5− whereas the higher amount of doping decreased the rate. Added 2-propanol to the system was found to increase the rate of decomposition of peroxomonosulfate. The proposed mechanism of the decomposition of PMS involves the reactions of the photogenerated valence band holes and the conduction band electrons of WO3, by radiation of wavelength ≥410 nm, in presence and absence of 2-propanol. The rate constants and quantum yields have also been evaluated. The photocatalytic decomposition of peroxomonosulfate is one of the few examples of a unimolecular reaction catalyzed by both the photogenerated holes (hvb+) and electrons (ecb−).
Normal Pressure Double Carbonylation of Aryl Halides Using Cobalt(II) Chloride in the Presence of either Sodium Sulfide or Sodium Borohydride
Authors: Itoh Kenji , Miura Masahiro , Nomura Masakatsu 
Published: July 2006

Abstract
Tetracarbonylcobaltate ion generated by a treatment of cobalt(II) chloride with either sodium sulfide or sodium borohydride under a normal pressure of carbon monoxide was capable of catalyzing carbonylation of aryl halides in the presence of calcium hydroxide and methyl iodide to give arylglyoxylic acids in good selectivity.
The Hammett Relationship in the Reduction of Aldehydes with 2-Propanol by Catalysis with Hydrous Zirconium Oxide
Authors: Shibagaki Makoto , Kuno Hideyuki , Takahashi Kyoko , Matsushita Hajime 
Published: July 2006

Abstract
A linear correlation of the Hammett relationship was obtained for a catalytic reduction of substituted benzaldehydes with 2-propanol with hydrous zirconium oxide. The reaction constant ρ was 1.35, indicating that the electronic effect on the reaction is larger than that on the standard one.
The Synthesis and Characterization of Manganese(III) Complexes with the General Formula of [Mn(X)(L)]n+ (n=0, 1) (X=Cl−, N3−, Pyridine, N-Methylimidazole, L=N,N′-[(Methylimino)bis(trimethylene)]bis[salicylideneaminate]: The X-Ray Crystal Structure of [Mn(N-MeIm)(L)][BPh4]
Authors: Akui Toshifumi , Ohyoshi Akira , Matsumoto Naohide , Okawa Hisashi 
Published: July 2006

Abstract
A series of manganese(III) complexes with the general formula of [Mn(X)(L)]n+ (n=0, 1) have been prepared and characterized, where X=Cl−, N3−, pyridine, N-methylimidazole, and L=quinquedentate Schiff base ligand N,N′-(methynmmo)bis(trimethylene)]bis[salicylideneaminate]. The X-ray analysis of [Mn(N-MeIm)(L)][BPh4] confirmed that the coordination geometry of the manganese(III) ion is a tetragonal bipyramid in which two axial positions are occupied by a central amine nitrogen atom N(3) and an imidazole nitrogen atom N(4), with elongated bond distances of Mn–N(3)=2.388(6) Å and Mn–N(4)=2.251(6) Å.
The Charge Carried by a Layer Formed by an Aggregation of Polyelectrolytes in a Solution Containing a Salt
Authors: Kaneko Tetsuo 
Published: July 2006

Abstract
A layer formed by the aggregation of polyelectrolyte molecules is charged according to the ionic dissociation of the layer in a simple salt solution. The charge carried by the layer is estimated on a basis of solutions of the Poisson-Boltzmann equation. It has been found that this charge is independent of the concentration, ns, of a salt, in spite of the permanence of the layer to counter ions when the density, ng, of charged groups in the polyelectrolyte molecules is much higher than the concentration ns. As the result, the charge may be given as a function of three parameters (temperature, density ng, and thickness of the layer) except for ns. Moreover, it has been found that the distribution of counter ions within the layer and their distribution in the vicinity of the layer may be independent of ns and that these distributions of counter ions may agree with that in a salt-free solution.
Application of the SPE Method to Organic Electrochemistry. IX. Reaction Profiles of an Iron Redox Couple Incorporated into Pt–Nafion with Ascorbic Acid
Authors: Ogumi Zempachi , Mizoe Toshiyuki , Takehara Zen-ichiro 
Published: July 2006

Abstract
Fe3+ has been incorporated into Pt–Nafion. The behavior of Fe3+ as a mediator was examined in detail in a system comprising the oxidation of l-ascorbic acid (AA) to dehydroascorbic acid (AD). The diffusion of AA in Nafion is slower than that of Fe3+. The concentration profiles of Fe3+ and AA in Pt–Nafion have been clarified and a reaction of the mediator with AA took place within a very narrow zone close to the surface. The averaged diffusion coefficients of Fe3+ and AA are 1.5×10−7 cm2 s−1 and 4.7×10−8 cm2 s−1, respectively.
A Novel Approach to the Enumeration of Reaction Types by Counting Reaction-Center Graphs Which Appear as the Substructures of Imaginary Transition Structures
Authors: Fujita Shinsaku 
Published: July 2006

Abstract
A novel method of enumerating reaction types is presented. The reaction types are formulated as reaction center graphs (RCGs) that are derived from a parent basic reaction graph (BRG) or from a parent reaction graph (RG) by the substitution of various atoms on the vertices and/or by the attachment of single, double, or triple par-bonds to the edges. The counting of the isomeric RCGs is solved by applying Pólya’s theorem to the derivation of a cycle index, in which different variables are introduced to the different orbits of the permutation group of a parent BRG (or RG). Various atom-figure and bond-figure inventories are described in order to count the isomers of RCGs. The numbers of the RCGs are given in the form of the coefficients of a generating function called an RCG-counting polynomial series.
A Molecular Orbital Study of Cyclodextrin Inclusion Complexes. I. The Calculation of the Dipole Moments of α-Cyclodextrin Aromatic Guest Complexes
Authors: Kitagawa Masaki , Hoshi Hajime , Sakurai Minoru , Inoue Yoshio , Chûjô Riichirô 
Published: July 2006

Abstract
The dipole moments of α-cyclodextrin(α-CD)-aromatic guest systems have been calculated by means of the CNDO/2 molecular orbital (MO) method in order to investigate the role of electrostatic interaction in the stabilization of the inclusion complexes. It is found that α-CD has a remarkably large dipole moment which amounts to 13.5 D and is directed from its secondary hydroxyl side (the wider rim) towards the primary hydroxyl side (the narrower rim). The dipole moments of the guests, benzene derivatives, run antiparallel to that of α-CD in the complexed state. The MO total energy of the α-CD-guest supermolecular complexes shows that these antiparallel-orientations are energitically more favorable than the reversed one. It is concluded that the electrostatic interaction, mainly dipole–dipole interaction, between the α-CD and the guest molecules plays an essential role in determining the guest orientation. On the basis of these results, it is deduced that during complexation the CD molecule undergoes appreciable amount of conformational change, suggesting that the “induced-fit” mechanism is operating when the guest molecule is admitted into the host cavity.
The Model Compounds and Conformational Analysis of Poly(thiotrimethylene) Using Molecular Mechanics Method
Authors: Miyasaka Taira , Yoshida Takaichi 
Published: July 2006

Abstract
Several model compounds of poly(thiotrimethylene), including one to four thiotrimethylene units, were studied by means of a molecular mechanics method. The geometric and statistical weight parameters were directly derived from the results of molecular mechanics calculations concerning several conformers of these model compounds. Although the first-order interactions of poly(thiotrimethylene) were significantly larger than those of poly(oxyalkylenes), the second-order interactions of this polymer were much smaller. The “gauche effect” by sulfur atoms seemed to be mainly caused by small second-order interactions. By means of the model, compounds including more than three repeating units, the calculated configuration-dependent properties were in better agreement with the experimental ones than that calculated earlier. The better agreement was obtained by varying some of the geometric parameters. Compounds including more than three repeating units of the polymer were available as model compounds. Since this was also true in poly(oxyalkylenes), it was found that a combination of the methods of molecular and statistical mechanics was sufficiently effective to investigate the configurational properties of poly(thiotrimethylene).
ESR Studies of Solvent and Pressure Effects on Spin Exchange of Nitroxide Radicals in Solution
Authors: Sueishi Yoshimi , Nishimura Norio , Hirata Koichi , Kuwata Keiji 
Published: July 2006

Abstract
The rate constants of spin exchange for 2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxyl (Tanone) in various solvents at high pressures were estimated from the line-broadening in ESR spectra. The rate constants of the spin exchange were in the range of 109–1010 M−1 s−1 and were compared with the calculated ones on the basis of the Smoluchowski–Stokes–Einstein equation. A significant disagreement between them was observed as the solvent viscosity decreased. The activation volumes estimated from the pressure dependence of the rate constant for the spin exchange were slightly smaller than those for diffusive processes. These findings suggest that the rate process for the spin exchange is virtually a diffusion-controlled one. An interpretation of activation volumes for diffusive process of spin exchange is given.
Rotamer Populations and Molecular Structure of 9-Isobutyl-1,4-dimethoxytriptycene: Further Evidence for the Presence of CH3···O Hydrogen Bond
Authors: Oki Michinori , Takiguchi Naoyoshi , Toyota Shinji , Yamamoto Gaku , Murata Shigeru 
Published: July 2006

Abstract
1H NMR spectra of the title compound at low temperatures show the presence of the sc conformer as a major constituent: ΔH°=0.9±0.3 kcal mol−1, ΔS°=5±2 cal mol−1 for the sc\ightleftarrowsap equilibrium. The line shape analysis of the spectra at various temperatures afforded the following activation parameters for the internal rotation about the C9–Ci-Bu bond: ΔH\eweq=8.8±0.3 kcal mol−1, ΔS\eweq=−5.0±1.2 cal mol−1 K−1 for the ap→sc process. X-Ray crystallography of the compound revealed that the molecule exists as sc conformers in the crystal. One of the methyl groups of the isobutyl group that directs inward relative to the triptycene skeleton, is placed very closely to the 1-methoxy-oxygen to indicate the presence of the CH3···O hydrogen bond. Implications of other structural parameters are also discussed.