bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, and Crystal and Molecular Structure of Bis(N-methyl-formamide)tetrakis(thiocyanato)cobalt(II)mercury(II), CoHg(SCN)4(HCONHCH3)2
Authors: Kinoshita Hisashi , Ouchi Akira 
Published: July 2006

Abstract
The title complex was synthesized and its crystal and molecular structure were determined by the single-crystal X-ray diffraction technique. The crystal is orthorhombic with a space group P21nb, a=14.953(4), b=15.955(4), c=7.6838(9) Å. The crystal was solvent by means of the heavy-atom method and the final R value was 0.059. The mercury atom is in the tetrahedral geometry, coordinated with four sulfur atoms of the thiocyanate (SCN) ions, and the cobalt atoms is in the octahedral geometry, coordinated with four nitrogen atoms of SCN ion and two oxygen atoms of N-methylformamide which occupy the cis positions. Each pair of different kinds of metal atoms is bridged by an SCN ion and are in a three-dimensional network. Twenty-four membered rings of Co3Hg3(SCN)6, where the metal atoms are arranged hexagonally in a chair-form, are condensed two-dimensionally approximately parallel to the (100) plane. All mercury atoms on one plane are bridged by SCN ions to the cobalt atoms of the polymeric plane next to the [100] direction, while the cobalt atoms are linked by SCN ions to the mercury atoms on the next plane of the opposite side. The mfa ligands take their positions in vacancy of the network.
Selective Modification of the Two Type I Copper Sites in Human and Bovine Ceruloplasmin with the Action of Azide and l-Cysteine
Authors: Sakurai Takeshi , Nakahara Akitsugu 
Published: July 2006

Abstract
The two type I copper sites of human and bovine ceruloplasmin (CP) were indirectly modified through the binding of N3− to types II and III copper ions. Based on the fact that the activities of CP’s modified with N3− were 85 and 47% for human and bovine CP, respectively, it was disclosed that the electronic and steric states of the “fast” type I Cu or “CuA” which is coupled with the types II and III copper ions was changed reversibly, whilst the “slow” type I Cu or “CuB” which is not coupled with the types II and III copper ions was changed to a type II copper ion and/or irreversibly reduced. On the other hand, the reaction of a limited amount of l-cysteine with CP gave the absorption and electron paramagnetic resonance spectra of CP whose CuB was selectively reduced. The treatment of this CP with 4,7-diphenyl-2,9-dimethyl-1,10-phenanthroline-4′,4″-disulfonate did not result in the selective removal of CuB.
Inversion at Selenium in the Bis(β-diketonato)[2-(methylseleno)-ethylamine]cobalt(III) Ion
Authors: Nakajima Kiyohiko , Kojima Masaaki , Fujita Junnosuke 
Published: July 2006

Abstract
The selenide (selenoether) complexes, [Co(β-dik)2(CH3SeCH2CH2NH2)]+ (β-dik: acac=2,4-pentanedionate, Clacac=3-chloro-2,4-pentanedionate, Meacac=3-methyl-2,4-pentanedionate, and dbme=1,3-diphenyl-1,3-propanedionate) were prepared and separated into two racemic pairs of the diastereomers (Δ(R)Λ(S) and Δ(S)Λ(R) isomers). The complexes in solution epimerize by inversion at the selenium atom, and the rates were followed by high-performance liquid chromatography in the temperature range of 30.3–55.0 °C in 0.05 mol dm−3 Na2SO4 (acac, Clacac, and Meacac complexes) or in methanol (dbme complex). The ΔG25°C\eweq values for inversion of [Co(β-dik)2(CH3SeCH2CH2NH2)]+ decrease in the order β-dik=Clacac(108)&gt;acac(106)&gt;dbme(104)&gt;Meacac(100 kJ mol−1), and the decrease in ΔG25°C\eweq comes mainly from a decrease in ΔH\eweq. The effect of substituents is electronic and the Hammett relationship was found to hold for the inversion rates of the acac, Clacac, and Meacac complexes.
The Crystal and Molecular Structure of 6-Bromo[2.2]paracyclo(4,8)[2. 2]metaparacyclophane
Authors: Koizumi Yosuke , Horita Hisanori , Otsubo Tetsuo , Kasai Nobutami , Misumi Soichi 
Published: July 2006

Abstract
The molecular structure of the title compound has been determined by means of X-ray diffraction. C26H25Br, M 417.4, orthorhombic, space group P212121, a=12.713(1), b=14.998(1), c=10.156(1) Å, V=1936.3(1) Å3, Dm=1.43 g cm−3, Dc=1.432 g cm−3 for Z=4.
Synthesis and Biological Activities of Acetylenic Fatty Acids and Their Esters
Authors: Nakatani Munehiro , Fukunaga Yuji , Haraguchi Hiroyuki , Taniguchi Makoto , Hase Tsunao 
Published: July 2006

Abstract
Eight terminal acetylenic fatty acids from 5-hexynoic to 12-tridecynoic acids and their methyl, ethyl, and isopropyl esters were synthesized via o-nitrophenyl selenides. These acids and esters all showed inhibitory effect on lettuce seed germination and seedling growth. The effect was dependent on the number of carbon atoms in acetylenic chain. 8-Nonynoic acid showed potent activity, and its methyl ester was the most effective among the test compounds. In addition, the acids showed antifungal activity which increased as the number of carbon atoms increased.
The Ability of the Proline Residue to Promote Successive-Intramolecular Hydrogen Bonds in Oligopeptides
Authors: Narita Mitsuaki , Isokawa Shizuko , Doi Masamitsu , Wakita Ryuhei 
Published: July 2006

Abstract
In order to investigate the ability of the Pro residue to promote helical folding in oligopeptides, the IR spectroscopic conformational study of the oligo(Leu)s containing the Pro residue was performed in dichloromethane. Their IR difference spectra suggested the occurrence of successive-intramolecular hydrogen bonds just like incipient α-helical structures formed by one, two, three, and so forth i→i–4 hydrogenbonding patterns, alluding to the ability of the Pro residue to promote helical folding in the peptides. However, the intensities of hydrogen-bonded absorption bands in the amide A region of each peptide strongly suggested that conformations of the peptides investigated were also contributed by other intramolecularly hydrogen-bonded folded structures, which had lower absorption coefficients. The initiation mechanism of successive-intramolecular hydrogen bonding in the peptides is apparently attributed to the disturbance of the β-sheet formation by the rotation of the tertiary peptide bond plane (Leu–Pro), that is, the restriction of the values of the backbone dihedral angles φ and ψ of the Pro residue due to the low flexibility of the pyrrolidine ring.
A Novel and Highly Efficient Asymmetric Synthesis of Optically Active Anthracyclinones
Authors: Suzuki Michiyo , Kimura Yoshikazu , Terashima Shiro 
Published: July 2006

Abstract
The bromolactonization of the optically active acetals derived from 2-acetyl-5,8-dimethoxy-3,4-dihydronaphthalene and (R,R)-N,N:N′,N′-tetraalkyltartaramide was found to proceed highly diastereoselectively, giving mixtures of the seven-membered bromo lactones and the bromohydrins. The predominantly produced bromo lactones could be effectively converted to (R)-2-acetyl-5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthol, the AB ring synthon of optically active 11-hydroxyanthracyclinones, &gt;95% ee, in one pot reaction. Application of the explored synthetic scheme to 2-acetyl-5,12-dimethoxy- and 2-acetyl-5-methoxy-3,4-dihydro-6,11-naphthacenedione similarly gave (R)-2-acetyl-2,5,12-trihydroxy- and (R)-2-acetyl-2,5-dihydroxy-1,2,3,4-tetrahydro-6,11-naphthacenedione, the advanced key synthetic intermediates of optically active 4-demethoxy- and 11-deoxy-4-demethoxyanthracyclinones, 94% ee and &gt;99% ee, respectively, by way of mixtures of the seven- and six-membered bromo lactones.
Photocatalytic Behavior of Di- and Triferrocenylbenzenes on Reduction of Methyl Viologen and Photochemical Hydrogen Evolution from Methanol under Visible Light
Authors: Akiyama Takeo , Kawaharada Yukihiko , Kondo Akira , Kajitani Masatsugu , Endo Akira , Shimizu Kunio , Sugimori Akira 
Published: July 2006

Abstract
1,4- and 1,3-Diferrocenylbenzenes (1a and 1b), 1,2,4- and 1,3,5-triferrocenylbenzenes (1c and 1d) can act as photocatalysts for photochemical hydrogen evolution from methanol in the 1–methyl viologen MV2+–triethanolamine-colloidal Pt-catalyst system under the irradiation with visible light. The order of the photocatalytic activities of 1 is 1d&gt;1c&gt;1a&gt;1b. The catalytic activities of 1 can be correlated to the E1⁄2 values. 1 acts as a photocatalyst in the wavelength region of λ&gt;440 nm, whereas it acts as a quencher for the formation of MV\underset.+ in the wavelength region of λ&lt;440 nm. The highest quantum yield of the formation of MV\underset.+ catalyzed by 1(1d: QMV\underset.+=0.028, at 480 nm) was obtained in the wavelength region where the intensity of the solar light is the largest.
Selenium and Tellurium Tetrachlorides as Reagents for the Conversion of Alcohols to Alkyl Chlorides and Tellurium Tetrachloride as a Lewis Acid Catalyst for Aromatic Alkylation
Authors: Yamauchi Takayoshi , Hattori Kaneaki , Mizutaki Shoichi , Tamaki Kentaro , Uemura Sakae 
Published: July 2006

Abstract
Selenium tetrachloride(SeCl4) reacts smoothly with alcohols in various nonpolar solvents to give the corresponding alkyl chlorides in 44–97% yield. Similar reaction also proceeds with tellurium tetrachloride (TeCl4), while the treatment of benzyl, 1-phenylethyl, and t-butyl alcohols with TeCl4 in aromatic solvents results in a high yield formation of alkylated aromatics instead of alkyl chlorides. Such Friedel-Crafts aromatic alkylation hardly occurs in the SeCl4 case. The chlorinating species is not chlorine which might be evolved by dissociation of SeCl4 or TeCl4, but the metal chloride itself. The conversion of optically active (R)-(+)-1-phenylethanol to 1-phenylethyl chloride proceeds with nearly complete racemization.
Enzymatic Esterolysis of Polymers Containing 2-Biphenylyl Ester Bonds in Side Chains
Authors: Ishikawa Tomomichi , Otsuki Makoto , Iwatsuki Toshiaki 
Published: July 2006

Abstract
The preparation and α-chymotrypsin-catalyzed esterolysis of polymeric substrates anchoring fungicidal biphenyl-2-ol are described. In order to obtain information regarding the influence of one type of polymeric backbone and the distance between a cleavable bond and a polymer main chain, poly(2-biphenylyl acrylate), poly(2-biphenylyl methacrylate), and poly(methacryloylamino acid 2-biphenylyl ester)s were studied. The esterolysis were evaluated by means of Michaelis constant Km and the catalytic reaction rate constant kcat. Poly(2-biphenylyl methacrylate) was a more suitable substrate than poly(2-biphenylyl acrylate). Poly[6-(methacryloylamino)hexanoic acid 2-biphenylyl ester] was the most suitable substrate in a series of polymers containing amino acid side chains with 2-biphenylyl ester terminal groups. The release rate of biphenyl-2-ol could also be controlled by using copolymers with an appropriate comonomer.
Preparation and Characterization of a Resin-Supported Palladium Catalyst
Authors: Uematsu Takayoshi , Umino Masao , Shimazu Shogo , Miura Masatoshi , Hashimoto Hidehisa 
Published: July 2006

Abstract
The process of the ligand release and the reduction of [Pd(NH3)4]-form sulfonic resin has been studied by chemical analysis, X-ray photoelectron spectroscopy and adsorption techniques. The removal of ammonia ligands remarkably increased with hydrogen treatment above 353 K, and was complete at around 393 K. It is suggested that the released ammonia partly transfers to –SO3− groups to form –SO3NH4 groups as the reduction proceeds. The dispersion of the metal particles prepared by hydrogen reduction ranged from 0.11 to 0.31 depending on the loading concentration of the palladium cation. The metal particles are considered to be entrapped in the pores of the resin. The formation of cationic palladium sites by the low temperature reduction is also suggested.
Catalytic Effects of MoCl3- and NiCl2-Containing Molten Salts for Hydroliquefaction of Morwell Brown and Taiheiyo Subbituminous Coals
Authors: Song Chunshan , Nomura Masakatsu 
Published: July 2006

Abstract
The catalytic effects of MoCl3–LiCl–KCl and NiCl2–LiCl–KCl molten salts were studied for the hydroliquefaction of Morwell brown and Taiheiyo subbituminous coals at 400 °C for 1 h in a batch reactor with an initial hydrogen pressure of 9.8 MPa. The conversion to pyridine-soluble materials and the yield of hexane-soluble materials (HS) with the MoCl3 catalyst were 82 and 42% for Morwell coal, and 84 and 61% for Taiheiyo coal, respectively. The conversion and HS yield with the NiCl2 catalyst were 87 and 43% for Morwell coal, and 82 and 56% for Taiheiyo coal, respectively. The HS yield of the catalytic runs was about 2.6–3.2 times higher than that of noncatalytic runs. This finding established the effectiveness of the two new catalysts for the hydroliquefaction of brown and subbituminous coals. Detailed analyses of the reaction products have revealed that these catalysts promoted a depolymerization of the coals and strongly catalyzed the hydrocracking of polynuclear aromatic structures of heavy products into hydroaromatic and aromatic structures with smaller ring sizes. Most of these smaller hydroaromatic and aromatic structures did not undergo much further ring-opening reactions. This accounts for the high HS selectivity of the catalysts.
Polystyrene Resin-Supported Aluminium Copper(I) Chloride as Selective Ethylene Adsorbent
Authors: Hirai Hidefumi , Nakamura Masahiro , Hara Susumu , Komiyama Makoto 
Published: July 2006

Abstract
Solid adsorbents for ethylene are prepared by stirring copper(I) chloride, aluminium chloride, and a macroreticular type polystyrene resin in carbon disulfide, followed by removal of the liquid phase. The adsorbents effectively adsorb ethylene at 20 °C under 1 atm, and exhibit no measurable adsorptions of nitrogen, hydrogen, and methane.
High Stereoselectivity of Tris[4-(l-menthyloxy)-1-(p-tolyl)-1,3-butandionato]lanthanoid(III)
Authors: Okawa Hisashi , Nakamura Michio , Shuin Y\={u}ko , Kida Sigeo 
Published: July 2006

Abstract
Tris[4-(l-menthyloxy)-1-(p-tolyl)-1,3-butanedionato]lanthanoid(III), [Ln(l-moba-Me)3](Ln=La, Pr, Nd, Eu, Gd, Dy, Ho, Er, Tm), showed a high stereoselectivity effected by intramolecular noncovalent interactions, giving rise to the cis-Δ form.
Molecular Structure of a Reductive Dimer of Pulegone
Authors: Kikuchi Mitsuko , Taira Zenei 
Published: July 2006

Abstract
The molecular structure of “bishydropulegone,” a reductive dimer of pulegone, was determined as (1R,3′aR,4R,6′R,7′aS)-7-′a-hydroxy-2′,2′,3′,3′,4,6′-hexamethylspiro[cyclohexane-1,1′-indan]-2-one by X-ray crystallographic analysis.
Interaction of Iron(III) Chloride with d-Fructose in an Acidic Solution
Authors: Araki Koji , Shiraishi Shinsaku 
Published: July 2006

Abstract
Complex formation between Fe(III) and d-fructose in an acidic solution was studied by electronic and CD spectroscopy, and the role of the complex in the photochemically-induced oxidation of d-fructose by Fe(III) was discussed.
A Kinetic Study of the Thermal Conversion of 1′,3′,3′-Trimethylspiro[2H-1-benzopyran-2,2′-indoline]-8-carboxylic Acid
Authors: Sueishi Yoshimi , Ohcho Masanobu , Yamamoto Shunzo , Nishimura Norio 
Published: July 2006

Abstract
The rate of the thermal conversion of 1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indoline]-8-carboxylic acid (8-COOH-SP) from its spiro form to its merocyanine form has been measured in several solvents at high pressures. Small solvent- and pressure-dependencies of the rate were observed. These results suggest that the electronic structure of the transition state of this reaction is nonpolar and that it is similar to that previously observed for the thermal conversion of so-called 6-nitrospiropyran from its merocyanine form to its spiro form.
Orthogonal Approximation and Classification of Molecules for Zero-Point Energy Shifts Due to H/D Isotope Substitutions
Authors: Oi Takao , Ishida Takanobu 
Published: July 2006

Abstract
Dozens of hydrogenous molecules have been classified for the approximation of the H/D isotope shifts in zero-point energies. The classification, based on their molecular structures, has yielded relative approximation errors of better than one percent with a few predictable exceptions. A further refinement of the classification has been suggested.
Photolytic Formation of a Uranium(V)–DMSO Complex and the Paramagnetic Shift of DMSO by Uranium(V)
Authors: Fukutomi Hiroshi , Harazono Toshie 
Published: July 2006

Abstract
A U(V)-DMSO complex (DMSO=dimethyl sulfoxide) formed by photoreduction of [UO2(dmso)5]2+ was stable in acid-free DMSO and a small quantum yield of U(V) was attributed to the difficulty in electron transfer from ligands to U(VI). The paramagnetic shift of DMSO by U(V) indicates that only the pseudo-contact shift is induced.
Formation of 2-Substituted 1,3-Diphenylindenes by an N-Bromosuccinimide Prompted Dehydrocyclization of 2-Substituted 1,3,3-Triphenyl-1-propenes
Authors: Yamamura Kimiaki , Miyake Hideyoshi , Sera Akira 
Published: July 2006

Abstract
The reactions of a series of 2-substituted 1,3,3-triphenyl-1-propenes with N-bromosuccinimide (NBS) afforded the corresponding 2-substituted 1,3-diphenylindenes in moderate yields. A reaction mechanism involving a novel free-radical intramolecular ring-closure reaction is suggested.
Carbon Dioxide-Promoted Telomerization of 1,2- and 1,3-Dienes with Benzenesulfinate Catalyzed by Palladium(0)\eweq
Authors: Inoue Yoshio , Hashimoto Harukichi 
Published: July 2006

Abstract
The telomerization of 1,2- and 1,3-dienes with benzenesulfinate dihydrate catalyzed by palladium(0) has been promoted by the presence of carbon dioxide.
Pressure and Temperature Effects on the Excess Conductance of the Hydroxide Ion in Water
Authors: Ueno Masakatsu , Sakata Yasushi , Tsuchihashi Noriaki , Shimizu Kiyoshi 
Published: July 2006

Abstract
The limiting molar conductances, Λ°, of sodium hydroxide were determined at 15, 25, and 40 °C as a function of the pressure up to 1500 kgf cm−2 (1 kgf cm−2=0.9807×105 Pa) from the conductances measured in a dilute concentration range (1×10−3–2×10−2M, 1 M=1 mol dm−3). The excess conductances at an infinite dilution, λ°E, of the hydroxide ion, as estimated by [λ°E(OH−)=Λ°(NaOH)−Λ°(NaCl)], were found to increase with an increase in the pressure and temperature, as well as those of the oxonium ion, λ°E(H3O+). However, there was a significant difference in the magnitude of λ°E, itself, and a slight difference in the magnitude of the pressure and temperature dependences of λ°E between hydroxide and oxonium ions. These results may be related to a difference between the proton-jump mechanisms of the hydroxide and oxonium ions.
Valence Coordinate Contributions to Zero-Point Energy Shifts Due to Hydrogen Isotope Substitutions
Authors: Oi Takao , Ishida Takanobu 
Published: July 2006

Abstract
The orthogonal approximation method for the zero-point energy (ZPE) developed previously has been applied to analyze the shifts in the ZPE, δ(ZPE), due to monodeuterium substitutions in methane, ethylene, ethane and benzene in terms of elements of F and G matrices. The δ(ZPE) can be expressed with a reasonable precision as a sum of contributions of individual valence coordinates and correction terms consisting of the first-order interactions between the coordinates. A further refinement in the precision is achieved by a set of small number of second-order terms, which can be estimated by a simple procedure.
The Regulation of Emulsion Polymerization of Styrene with Anionic–Nonionic Emulsifier Mixtures
Authors: Kato Kazufumi , Kondo Harumi , Esumi Kunio , Meguro Kenjiro 
Published: July 2006

Abstract
The emulsion polymerization of styrene was carried out in the presence of mixtures of a nonionic surfactant (poly(oxyethylene) hexadecyl ether; BC-20) and an anionic surfactant (sodium dodecyl sulfate; SDS or lithium perfluorooctanesulfonate; LiFOS). The polymerization rate changed with the hydrophile-lypophile balance (HLB) of the BC-n series. The polymerization rate considerably increased on the addition of SDS or LiFOS. However, the further addition of LiFOS caused a gradual depression of the polymerization rate. The polymerization rate was not dependent on the amount of styrene solubilized in the mixed emulsifier solution. The particle sizes decreased remarkably on adding SDS. The molecular weights of polystyrene in latex synthesized in mixed emulsifier solutions were larger than those in a single emulsifier solution. The molecular-weight distributions of polystyrene formed in mixed emulsifier solutions were wider than those of polystyrene formed in a single emulsifier solution. These results may be attributed to properties such as the composition and the charge density of the mixed micelles, and to the solubilized amount of styrene monomer in the mixed nonionic-anionic emulsifier solutions.
Stopped-Flow Small-Angle X-Ray Scattering Study on the Acid-Denaturation of Taka-Amylase A
Authors: Hozaki Tatsuya , Kato Mitsunori , Sato Mamoru , Tanaka Nobuo , Morimoto Yukio , Hata Yasuo , Katsube Yukiteru , Kasai Nobutami 
Published: July 2006

Abstract
A stopped-flow small-angle X-ray scattering method was applied to study the structural change of Taka-amylase A by acid-denaturation. The structural change could be described by two successive steps. The first step is described by a change in the eccentricity of a prolate ellipsoid from 2.0 to 2.4; this was estimated by a comparison between the observed scattering profile and the theoretical scattering function of the prolate ellipsoid. The second step supposes that the X-ray scatterer in a solution comprises two kinds of particles with large and small radii of gyration. The X-ray scatterer with a large radius expands with time. By contrast, the radius of gyration of the small scatterer corresponds to that of a native Taka-amylase A monomer and it remains unchanged. These facts imply that in the denaturation of Taka-amylase A the molecule is prolonged by a partial unfolding of the polypeptide chain and then aggregates with each other.
The Arrhenius Parameters for the Reactions of N(24S3⁄2) with Halogen Molecules
Authors: Umemoto Hironobu , Uchida Teruo , Nakagawa Seiko , Tsunashima Shigeru , Sato Shin 
Published: July 2006

Abstract
The temperature dependence of the rate constants for the reactions of ground-state atomic nitrogen with halogens were measured by means of a pulse radiolysis-resonance absorption technique. The rate constants for iodine and bromine were well expressed by the following Arrhenius expressions below 410 K: k(N+I2)=1.1×106 exp(−1170/T); k(N+Br2)=1.1×105 exp(−1490/T), in units of m3 mol−1 s−1. The rate constant for the reaction with chlorine was found to be 1.1×103 m3 mol−1 s−1 at 411 K. Below this temperature, the rate constants for N+Cl2 were too small to be measured. The preexponential factors for the I2 and Br2 reactions were found to be much smaller than the semiempirically calculated ones. These small preexponential factors suggest that the reactions between N(4S) and halogens proceed via nonadiabatic routes.
The Epitaxial Growth of the Methyl Triacontanoate Crystal
Authors: Ueda Yasukiyo 
Published: July 2006

Abstract
Methyl triacontanoate (MT) was deposited on the cleavage face of the KCl crystal in vacuo. The MT film was composed of V-shaped crystals growing along two directions crossing at 32°, and these crystals intersected at right angles to each other. The bisectional direction of the V-shaped crystals corresponds to the [110] direction of the substrate crystal. The electron-diffraction pattern from the film consisted of the reflection spots corresponding to the (hkl)s planes of the subcell and the series of 00l reflections in the small-angle region. The crystal structure of the deposited MT crystal was monoclinic in form. The (110) plane of the MT crystal was oriented parallel to the substrate (001) plane, and its c-axis was parallel to the [110] direction of the substrate crystal. The V-shaped crystal was explained by the molecular arrangement in the epitaxial growing crystals. When the substrate was kept at a higher temperature than the melting point of MT, the deposit coagulated to disk-like crystals whose c-axis was perpendicular to the substrate.