bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optically Active S-Bridged CoIIIPdII Polynuclear Complexes Derived from ΔΔ-[Ni{Co(aet)2(R-pn)}2]4+(aet = 2-Aminoethanethiolate, R-pn = (R)-1,2-Propanediamine)
Authors: Yamada Yasunori , Maeda Yoko , Konno Takumi , Fujisawa Kiyoshi , Okamoto Ken-ichi 
Published: September 2002

Abstract
The substitution reaction of ΔΔ-[Ni{Co(aet)2(R-pn)}2]4+ with equimolar Na2[PdCl4] in water gave selectively an optically active trinuclear complex, ΔΔ-[Pd{Co(aet)2(R-pn)}2]4+ (1). On the other hand, an optically active dinuclear complex, Δ-[PdCl2{Co(aet)2(R-pn)}]+ (2), was also obtained by a two-molar equivalent addition of Na2[PdCl4] under the same reaction condition. Similarly, the reaction of ΔΔ-[Ni{Co(aet)2(R-pn)}2]4+ with two molar equivalent [Pd(NO3)2(bpy)] produced an optically active dinuclear complex, Δ-[Pd(bpy){Co(aet)2(R-pn)}]3+ (3). The crystal structures of complexes 1, 2, and 3 were determined by X-ray crystallography. Each of the Co atoms in 1, 2, and 3 is coordinated by two aet and one R-pn ligands to take an approximately octahedral geometry. The Pd atom in 1 is coordinated by four S atoms from two cis(S)-[Co(aet)2(R-pn)]+ units. The Pd atom in 2 is ligated by two S atoms from one cis(S)-[Co(aet)2(R-pn)]+ unit and two Cl atoms, while the Pd atom in 3 is coordinated by two S atoms from one cis(S)-[Co(aet)2(R-pn)]+ unit and two N atoms in bpy. All of the Pd atoms in 1, 2, and 3 take an almost square-planar geometry. These complexes are also characterized on the basis of the electronic absorption, CD, and 13C NMR spectra. The interconversions of the trinuclear and dinuclear complexes obtained in this work are discussed.
Spectroscopic and Electrochemical Properties of Cytochrome c551 from Alcaligenes xylosoxidans GIFU 1051
Authors: Deligeer  , Kataoka Kunishige , Yamaguchi Kazuya , Suzuki Shinnichiro 
Published: September 2002

Abstract
Spectroscopic and electrochemical characterizations of cytochrome c551 from a denitrifying bacterium, Alcaligenes xylosoxidans GIFU 1051, have been performed. The spectral data indicate that the oxidized and reduced proteins have a six-coordinate low-spin heme. The fast electron-transfer process from cytochrome c551 to cognate Cu-containing nitrite reductase was electrochemically observed.
Adsorption of Tetravalent Metal Ions to Chelating Resins Containing Iminodiacetic Acid Groups
Authors: Yuchi Akio , Yoshida Norihito 
Published: September 2002

Abstract
With respect to the selectivities, the compositions of species formed by the adsorption of tetravalent metal ions (M4+) to chelating resins containing iminodiacetic acid groups (-LH2) were estimated from the shapes of the adsorption curves and the infrared absorption spectra of the polymer complexes: [-LM(OH)2] for Zr4+ and Hf4+, while [(-LH)4M], [(-L)(-LH)2M], and [(-L)2M] for Th4+.
Crystal Structure and Spectrochemical Properties of a Dinuclear Palladium(II) Complex with 2,3,5,6-Tetra(2-pyridyl)pyrazine
Authors: Yamada Yasunori , Miyashita Yoshitaro , Fujisawa Kiyoshi , Okamoto Ken-ichi 
Published: September 2002

Abstract
A dinuclear Pd(II) complex bridged with 2,3,5,6-tetra(2-pyridyl)pyrazine (tppz) was newly obtained by the reaction of Pd(II) ion with tppz. The crystal structure of the dinuclear complex was determined by X-ray structural analysis. The spectrochemical properties of the complex are also discussed in relation to the stereochemical behavior.
Binding Interaction of the Trimethylsilyl Cation with Oxygen and Nitrogen Bases in the Gas Phase. Acetopheones, Benzaldehydes, Pyridines, Anilines, and N,N-Dimethylanilines
Authors: Mustanir  , Shimada Kenji , Ohta Fumio , Mishima Masaaki 
Published: September 2002

Abstract
The gas-phase basicities toward the trimethylsilyl cation, GB(Me3Si+), were determined for a series of acetophenones, benzaldehydes, pyridines, anilines, and N,N-dimethylanilines by measuring the equilibrium constants of trimethylsilyl cation transfer reactions. GB(Me3Si+) increases in the order aniline &lt; benzaldehyde &lt; acetophenone &lt; N,N-dimethylaniline &lt; pyridine, while GB(H+) increases as benzaldehyde &lt; acetophenone &lt; aniline &lt; pyridine &lt; N,N-dimethylaniline. The effects of ring substituents on the GB(Me3Si+) of the respective bases are, however, linearly correlated with the corresponding proton basicities with a slope of 0.8 to 1.0, showing family-dependent linear relationships. Furthermore, an analysis of the substituent effects on the GB(Me3Si+) of acetophenone and benzaldehyde showed that the ρ values are close to those for the proton basicities, though the resonance demand of Me3Si+ adduct ions is slightly reduced compared with that for the protonated ones. DFT calculations at the B3LYP/6-31+G(d) level of theory reproduced such a trend in substituent effects as well as the family-dependent linear correlations between the H+ and Me3Si+ basicities. Both the experimental and theoretical results lead to the conclusion that the binding interactions of Me3Si+ with O and N atoms of organic bases have a pronounced covalent character to a similar degree as that of a proton.
An Attempted Synthesis of 8-Shaped Circulene: Synthesis and Characterization of [2.2](4,4′)Biphenylo(3,11)dibenzo[c, l]chrysenophane and Its Cyclophadiene
Authors: Yano Koji , Osatani Mitsunobu , Tani Keita , Adachi Tomohiro , Yamamoto Koji , Matsubara Hiroshi 
Published: September 2002

Abstract
The syntheses of the title compounds are described. The unusually strained structures were supported by their 1H NMR spectra, electronic spectra, and X-ray crystallographic analyses.
Synthesis, Characterization, and Controlling Morphology of an Aryl Ether Dendrimer Containing a Dichalcogenide Bond as the Core
Authors: Takaguchi Yutaka , Suzuki Shinji , Mori Takahiro , Motoyoshiya Jiro , Aoyama Hiromu 
Published: September 2002

Abstract
A poly(benzyl ether) dendron with a thiol group or a selenocyanate group at the focal point was synthesized and well characterized, and then used for the controlling morphology. The molecules show a reversible redox behavior between dendrons and dendrimer dichalcogenides, being achieved under chemical reactions, although a dendrimer having selenium atoms has never been reported. Furthermore, dendrimer dichalcogenides underwent an dechalcogenation reaction upon a treatment with hexaethylphosphorous triamide or photoirradiation to give dendrimer chalcogenides.
Synthesis of 3-Ethoxyisoxazole Derivatives and 3-Ethoxy-1H-pyrazole Derivatives from β-Oxo Thionoesters
Authors: Ohta Tetsuo , Fujisawa Hironori , Nakai Yasuto , Furukawa Isao 
Published: September 2002

Abstract
3-Ethoxyisoxazoles and 3-ethoxy-1H-pyrazoles were obtained in high yields from β-oxo thionoesters. The reaction of the ethyl β-oxo thionoesters with hydroxylamine hydrochloride in the presence of triethylamine at room temperature for 2 h gave the ethyl 3-oxopropiohydroximates and their hemiacetals, which were easily converted to the 3-ethoxyisoxazoles by refluxing for 3 h at pH 3—5. On the other hand, the reaction of the ethyl β-oxo thionoesters with hydrazine derivatives in the presence of triethylamine for 3—8 h at room temperature directly yielded the 3-ethoxy-1H-pyrazoles.
Synthesis, Properties, and Redox Behaviors of Di- and Trications Composed of Di(1-azulenyl)methylium Units Connected by p- and m-Phenylene and 1,3,5-Benzenetriyl Spacers
Authors: Ito Shunji , Morita Noboru , Asao Toyonobu 
Published: September 2002

Abstract
The titled stable di- and trications composed of di(1-azulenyl)methylium units connected by p- and m-phenylene and 1,3,5-benzenetriyl spacers, i.e., 1,3- and 1,4-phenylenebis[bis(3-methyl- and 3,6-di-t-butyl-1-azulenyl)methylium] bis(hexafluorophosphate)s (4a, 4b·2PF6- and 5a, 5b·2PF6-), and 1,3,5-benzenetriyltris[bis(3,6-di-t-butyl-1-azulenyl)methylium] tris(hexafluorophosphate) (6·3PF6-), were prepared by hydride abstraction of the corresponding hydrocarbons. In spite of di- and tricationic structures, 4a, 4b, 5a, 5b, and 6 showed high stabilities with large pKR+ values due to the effects of 1-azulenyl substituents. The two cation units in the dications 4a, 4b and 5a, 5b were neutralized simultaneously at the pH of 11.2—12.1 ± 0.2. The pH correspond to the average of the pKR+ values of dications and half-neutralized monocations. 3,6-Di-t-butyl substituents on 1-azulenyl groups increased solubilities and reversibilities of both reduction and oxidation upon cyclic voltammetry (CV). In contrast to the dications, the three cation units in the trication 6 were neutralized stepwise at the pH of 9.1 ± 0.2, 10.9 ± 0.2, and 12.7 ± 0.2, respectively. The electrochemical oxidation of di- and trications 4b, 5b, and 6 exhibited a reversible wave at +0.87— +0.89 V (V vs. Ag/Ag+) upon CV, although dications 4a and 5a showed irreversible waves in the similar potential ranges. The electrochemical reduction of m-phenylene-connected dications 4a and 4b showed two very closely spaced reduction waves at -0.65— -0.82 V upon CV. In the case of p-phenylene-connected dications, 5a and 5b showed a one-step, two-electron reduction wave at -0.47 and -0.55 V, respectively, upon CV. The reduction wave corresponds to the formation of an unstable closed-shell molecule. The reduction of trication 6 showed irreversible waves in the potential ranges similar to those of dication 4b.
A Facile Synthesis of Novel Liquid Crystalline Materials Having a Trifluoromethoxy Group and Their Electro-Optical Properties
Authors: Kanie Kiyoshi , Takehara Sadao , Hiyama Tamejiro 
Published: September 2002

Abstract
Novel liquid crystals (LCs) containing a trifluoromethoxy group connected to a cyclohexane mesogen or to an alkyl tail were prepared through an oxidative desulfurization-fluorination reaction of the corresponding dithiocarbonates. They were compared with LCs containing a methoxy group with respect to phase transition behavior and physical and electro-optical properties. Most of the CF3O-substituted LCs exhibited in a wide range of temperatures LC phases depending on the type of a mesogenic structure. LCs with a trifluoromethoxycyclohexane mesogen were shown to be thermally more stable than the LCs with a trifluoromethoxybenzene mesogen. LCs having a trifluoromethoxyalkyl tail show physical and electro-optical properties favorable to materials for not only TN-LCDs but TFT-addressed TN-LCDs. Furthermore, 3-β-CF3O-substituted cholestane was shown to be a potential chiral dopant for TFT-addressed TN-LCDs.
Structural Elucidation of 1,3-Phenylenebis(methylene)-Bridged Calix[6]arenes with Four Uncapped Hydroxy Groups
Authors: Saiki Toshiyuki , Akine Shigehisa , Goto Kei , Tokitoh Norihiro , Kawashima Takayuki , Okazaki Renji 
Published: September 2002

Abstract
1,3-Phenylenebis(methylene)-bridged calix[6]arenes with four uncapped hydroxy groups at the lower rim and various kinds of functionalities on the bridging unit were synthesized. Their structures in solution and in the crystalline state were determined by NMR spectroscopy, molecular mechanics calculations, and X-ray crystallographic analyses. They were found to adopt a pinched cone conformation, where the bridging 1,3-phenylenebis(methylene) unit lies below in such a way that it forms the bottom of the cone. There is a strong intramolecular hydrogen bonding network forming a cyclic array in these molecules; this network is considered to play an important role in the stabilization of the pinched cone conformation. The conformational mobility of the bridging unit was also investigated. It was found that the steric demand of the central functionality has a great influence on the swinging motion of the bridging unit.
Electrochemical Growth and Charge-Transport Properties of Polyaniline/Poly(styrenesulfonate) Composite Films
Authors: Komura Teruhisa , Mori Kouji , Yamaguchi Takahiro , Takahashi Kousin 
Published: September 2002

Abstract
The kinetic parameters of charge transport in composite-modified electrodes were measured as a function of the electrode potential, film thickness, solution pH, and counter ion composition by electrochemical impedance spectroscopy. The impedance characteristics of composite films were analyzed on the basis of the diffusion-migration transport of both holes and protons in the film. Incorporation of the polyanion with the host matrix produced a more compact deposite. A slow growth of the composite film during electropolymerization was ascribed mainly to its low electronic conductivity caused by poor contacts among polyaniline chains. Poly(styrenesulfonic acid) lowered the coupled diffusion coefficient of the charge carriers by a factor of ten. The relationships between the kinetic parameters and the oxidation and protonation levels of polyaniline suggested that the rate of charge transport through the composite film was controlled by electron transport, which occurred probably via interchain electron hopping.
Tributylmanganate(II)-Mediated Cyclization of Enynes
Authors: Usugi Shinichi , Shinokubo Hiroshi , Oshima Koichiro 
Published: September 2002

Abstract
Treatment of enynes with tributylmanganate(II) provided cyclized products containing alkylidene substituents. 1-Tridecen-6-yne or 1-tetradecen-7-yne gave 1-heptylidene-2-methylcyclopentane or 1-heptylidene-2-methylcyclohexane in 67 or 50% yield, respectively upon treatment with tributylmanganate(II). The reaction of dimethylvinylsilyl ether of 3-decyn-1-ol with tributylmanganate(II) afforded 4-heptylidene-2,2,3-trimethyl-1-oxa-2-silacyclohexane in good yield.
Hydration Properties of an Amino Sugar-Containing Synthetic Polymer by DSC and NMR Spectroscopy
Authors: Hirata Yuichi , Nakagawa Tsutomu 
Published: September 2002

Abstract
Poly(D-glucopyranosyl-α(1 → 6)-2-deoxy-2-methacrylamido-D-mannitol-co-D-glucopyranosyl-α(1 → 6)-2-deoxy-2-methacrylamido-D-glucitol) (poly(MAGPM-co-MAGPG)) was prepared by radical polymerization from methacrylamide monomers which were synthesized by the methacryloylation of amino sugars. The fraction of a different state of water in poly(MAGPM-co-MAGPG) was determined using DSC. The temperature dependence on the chemical shift of the 1H NMR was different between the low and high water retentions. The 17O spin-lattice relaxation time of water in poly(MAGPM-co-MAGPG) was compared to that of glucose, Palatinit®, and PVA. The interaction between the water and the hydroxy groups in poly(MAGPM-co-MAGPG) is strongly affected not only by the mobility of the sugar side chain, but also by the highly concentrated hydroxy groups along the hydrophobic main chains. The sugar side chain in poly(MAGPM-co-MAGPG) has a considerably higher hydration ability in comparison with glucose, Palatinit®, and PVA, although these substances have a hydroxy group as a hydrophilic group in common.
Reversible Control of the Pitch of Cholesteric Liquid Crystals by Photochromism of Chiral Fulgide Derivatives
Authors: Sagisaka Toshiya , Yokoyama Yasushi 
Published: September 2002

Abstract
When an enantiomer of resolved indolylfulgide (1) or either of the (R)-binaphthol-condensed indolylfulgides (2, 3) was mixed with a nematic liquid crystal (5CB), the cholesteric phase was induced. Their cholesteric pitches were reversibly changed by photoirradiation. Whereas the twisting ability of the cholesteric pitch (βM) was larger for the colorless form than for the colored form in the case of 1, it was larger for the colored form than for the colorless form in the cases of 2 and 3. In addition, βM of 1 is generally smaller than that of 2 and 3. These phenomena were explained in terms of the helical conformation of the hexatriene moiety of fulgides and the chirality of the binaphthol moiety.
The cholesteric sense of a fulgide-doped liquid crystal was changed between plus and minus reversibly by the pre-doping of the chiral formaldehyde acetal of 1,1′-bi-2-naphthol ((S)-4).
Preparation of Fibrous TiO2 Material Using an Organogelator
Authors: Kobayashi Satoshi , Hanabusa Kenji , Suzuki Masahiro , Kimura Mutsumi , Shirai Hirofusa 
Published: September 2002

Abstract
A TiO2 material with a fibrous structure was prepared using an organogelator, Z-L-Ile-NHC18H37, as a structure-forming agent for the sol-gel polymerization of titanium tetraisopropoxide, Ti[OCH(CH3)2]4. Z-L-Ile-NHC18H37 is an excellent gelator that can harden metal alkoxide, mainly by forming intermolecular hydrogen-bonds. The gelling phenomenon is attributed to the formation of a three-dimensional network based on fibrous aggregates in organic fluids. When Z-L-Ile-NHC18H37 is used as a structure-forming agent for sol-gel polymerization, the unique structure of the fibrous TiO2 material is created by the hydrogen-bonds between the fibrous gelator aggregates and oligomeric titanias in the sol-gel polymerization system.
High Magnetic Field Effects on Interdigitated Microarray Electrodes
Authors: Nishiyama Satoko , Aogaki Ryoichi 
Published: September 2002

Abstract
High magnetic field effects were determined for a typical electrochemical reaction, the oxidation of hexacyanoferrate(II) to hexacyanoferrate(III) on interdigitated microarray electrodes. A characteristic dependence on the magnetic field direction was observed. Using a unique feature of the microarray electrode, an attempt was made to obtain a new method to analyze the components of the flux, and a hopeful way was shown to apply these microarray electrodes in a magnetic field.
Continuously Changing the Conformational Dependence of Saponite Hybrid Materials on the Intercalation Degree: Electric Linear Dichroism of Stilbazolium Derivatives Intercalated in Saponite Clay
Authors: Sasai Ryo , Shichi Tetsuya , Gekko Kunihiko , Takagi Katsuhiko 
Published: September 2002

Abstract
The molecular alignmet of 2- and 4-[4-(dimethylamino)styryl]-1-ethylpyridinium cations (2- and 4-DASEP, respectively) adsorbed on saponite clay and suspended in N,N-dimethylformamide (DMF) has been investigated by the electric linear dichroism (ELD) method. An ELD analysis of the saponite clay complex involving 4-DASEP molecules in DMF indicated that although the tilt angle of the 4-DASEP molecular plane increased considerably from 14.1 to 32.1°, the roll angle remained constant at ca. 31°, with a coverage of 10 to 100% of 4-DASEP molecular in saponite. In contrast, the tilt and roll angles of the corresponding positional isomer, 2-DASEP, on the clay surfaces slightly increased with the same coverage degrees. The change in tilt and roll angles in the 2- and 4-DASEP molecules may be significantly influenced by the structural variation of the guest molecules, especially the steric hindrance around the pyridinium N+ atoms. The conformational structure of the adsorbed stilbazolium cations in saponite is discussed based on these results.
Fabrication and Characterization of Meso-Macroporous Anatase TiO2 Films
Authors: Ito Seigo , Yoshida Shoichiro , Watanabe Tadashi 
Published: September 2002

Abstract
A porous TiO2 film possessing both meso-sized (2—50 nm) pores and macro-sized (100—300 nm) pores has been fabricated for the first time by coating an SnO2 substrate with a paste consisting of secondary TiO2 submicroparticles, poylethylene glycol, hydroxypropyl cellulose and water, followed by calcination. The macropores are formed most probably by phase separation between the TiO2 particles and the polymers in the course of drying of the coated paste. The meso-macroporous TiO2 film thus prepared has a thickness of ca. 10 μm by four-fold coating, and is characterized by a large surface area arising from the mesopores in the secondary TiO2 particles, and by the presence of wide channels within the film. The film fabricated by calcination at 550 °C for 30 min was composed of pure anatase with high crystallinity. These features are favorable to construct an electrode for dye-sensitized photoelectrochemical cells.
Enhanced Decomposition of Dichloromethane in Air by Multi-Pass Electron Beam Irradiation
Authors: Wahyuni Sri , Hirota Koichi , Hakoda Teruyuki , Arai Hidehiko , Hashimoto Shoji , Kawamoto Fumio , Mukunoki Yasuo 
Published: September 2002

Abstract
The decomposition of dichloromethane (CH2Cl2) in model air gases (concentration, around 100 ppm) by electron beam (EB) and γ-ray irradiation was studied using batch-type glass reactors of 500 ml volume. The addition effect of water on the decomposition was also investigated. In dry air, one-pass EB irradiation (10.7 kGy s-1) induced only 65% decomposition, even at 32 kGy, but the γ-ray irradiation (2 kGy h-1) or EB multi-pass irradiation (1.33 kGy s-1) decomposed CH2Cl2 100% at 32 kGy. Water addition (4 ml) enhanced the decomposition percentage to 96% at 16 kGy, even by one-pass irradiation. In dry air, the formation of CO2, CO, phosgene and chloroform was confirmed. The mechanism for the above addition effect was considered as well as for the multi-pass irradiation effect.
Synthetic Incorporation of Metal Complexes into Nucleic Acids and Peptides Directed toward Functionalized Molecules
Authors: Shionoya Mitsuhiko , Tanaka Kentaro 
Published: September 2002

Abstract
Novel synthetic approaches for incorporation of metal complexes into nucleic acids and peptides are described. First, novel artificial β-C-nucleosides bearing a chelator nucleobase (2-aminophenol, catechol, or o-phenylenediamine) have been synthesized. These artificial nucleobases were introduced for alternative base pairing through metal coordination instead of the hydrogen bonding in natural DNA. 1H NMR and mass spectral studies clearly showed that o-phenylenediamine-type nucleoside forms a stable 2 : 1 square-planar complex with a PdII ion, providing an alternative DNA base pairing through metal complexation. Secondly, an efficient strategy for the liquid-phase synthesis of cyclic metallopeptides having a repeating Gly-L-Cys(terpyPtII) sequence, cyclo[-Gly-L-Cys(terpyPtII)-]nCln (n = 3, 4), has been developed. These cyclic metallopeptides were obtained by cyclization of the corresponding linear peptides, H2[-Gly-L-Cys(terpyPtII)-]nOH·(CF3CO2)n+1 (n = 3, 4), in moderate yields. The former cyclic hexapeptide was found to act as a positively charged anion receptor. This synthetic approach would provide a powerful tool for arraying metal centers on cyclopeptide frameworks.
Classification and Prediction of Reagents' Roles by FRAU System with Self-Organizing Neural Network Model
Authors: Satoh Hiroko , Funatsu Kimito , Takano Keiko , Nakata Tadashi 
Published: September 2002

Abstract
The classification and prediction of the roles for reagents in reactions are presented. The same dimensional representation of various reagents independent of the number of atoms was achieved by selecting representative factors by the FRAU (Field-characterization for Reaction Analysis and Understanding) system. Training of a self-organizing model considering both negative and absent data was accomplished by modifying the original counter-propagation (CP) type of Kohonen neural network to treat absent data differently from negative data. The modified CP Kohonen neural network successfully classified the reagents and produced a reagent-roles correlation model that gives good answers predicting roles of the reagents.