bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics and Mechanism of the Complex Formation Reactions of Cobalt(II) with Chloride, Bromide, Iodide, and Azide Ions, 2,2′-Bipyridine, 2,2′ : 6′,2″-Terpyridine, and Tris(2-pyridyl)amine in Hexamethylphosphoric Triamide
Authors: Abe Yuriko , Kitamura Naoko
Published: July 2006

The kinetics of the complex formation reactions of cobalt(II) with chloride, bromide, iodide, and azide ions, 2,2′-bipyridine (bpy), 2,2′: 6′,2″-terpyridine (terpy), and tris(2-pyridyl)amine (tpya) has been studied by stopped-flow spectrophotometry in hexamethylphosphoric triamide (HMPA) at a constant ionic strength of 0.06 mol dm−3. The reaction mechanism is discussed on the basis of the obtained formation rate constants, activation enthalpies, and activation entropies. An associative interchange mechanism for the complex formation reaction of cobalt(II) with halide ions is suggested.
Synthesis and Magnetic Property of Imidazolate-Bridged Cu(II)–M(II)–Cu(II) Complexes (M = Zn, Cu, Ni, Co, Mn)
Authors: Matsumoto Naohide , Inoue Keiji , Ohba Masaaki , \\={O}kawa Hisashi , Kida Sigeo
Published: July 2006

A series of imidazolate-bridged trinuclear complexes [Cu(A)M(hfac)2Cu(A)] (M = Zn2+, Cu2+, Ni2+, Co2+, Mn2+) have been prepared, where H2A = 4-(6-methyl-8-hydroxy-2,5-diazanonane-1,5,7-trienyl)imidazole and Hhfac = hexafluoroacetylacetone. The magnetic susceptibility data (4.2–300 K) were well reproduced by the equation based on the spin-Hamiltonian H = −2JCuM (SCu1·SM+SM·SCu2) to give the coupling parameters of JCuCu = −52.5 cm−1 (SCu = 1⁄2), JCuNi = −20.3 cm−1 (SNi = 1), JCuCo = −13.2 cm−1 (SCo = 3⁄2), and JCuMn = −4.5 cm−1 (SMn = 5⁄2).
Optical Resolution by Supercritical Fluid Chromatography Using Polysaccharide Derivatives as Chiral Stationary Phases
Authors: Kaida Yuriko , Okamoto Yoshio
Published: July 2006

The optical resolution of ten racemates by supercritical fluid chromatography (SFC) was investigated using phenylcarbamates of cellulose and amylose and 4-methylbenzoate of cellulose as chiral stationary phases (CSPs) and carbon dioxide–alcohol as a mobile phase. The optical resolving abilities of phenylcarbamates of both cellulose and amylose in SFC were low compared with those in high-performance liquid chromatography (HPLC). However, 4-methylbenzoate of cellulose showed a slightly better optical resolving ability in SFC than in HPLC.
Gas Chromatographic Determination of Solvation Number by an Investigation of the Extraction Processes
Authors: Arpadjan Sonja , Vassileva E , Velev V , Chanev Ch
Published: July 2006

A simple gas chromatographic method for the determination of the solvation number by an investigation of the extraction processes using MIBK as the solvent has been proposed. Gas chromatography was applied for the determination of the solvation number by extraction of the halometallic acids HFeCl4, HMoO2Cl3 in MIBK as well as by extraction of BiCl4− and SbCl4− as ion-associate complexes with long-chain quaternary ammonium salts in MIBK.
Spectrophotometric Determination of Trace Silver with Sodium 2-(8-Hydroxyquinolin-5-ylazo)benzoate
Authors: Saran Nil Raghaw , Umashanker V , Ramanaiah G V
Published: July 2006

The reaction between silver and sodium 2-(8-hydroxyquinolin-5-ylazo)benzoate in aqueous media in presence of Na–K tartrate at pH 5.2–6.1 results in an intense purple color which is stable for at least 24 h. The molar absorptivity and Sandell’s sensitivity at 525 nm are 3.65 × 104 dm3 mol−1 cm−1 and 0.0029 μg cm−2, respectively. The method was applied to the determination of silver in geological samples.
The Stereochemistry of the Sulfur Atom of 4,7-Dimethyl-6-phenyl-5,6,7,8-tetrahydro-4H-1,3,2,6-dioxathiazocine 2-Oxides
Authors: Nishiyama Tomihiro , Miyatake Shinji , Yamaguchi Hiromasa , Yamada Fukiko
Published: July 2006

The reaction of N-(2-hydroxypropyl)-N-(2-hydroxy-1-methylethyl)aniline with thionyl chloride afforded four isomers of 4,7-dimethyl-6-phenyl-5,6,7,8-tetrahydro-4H-1,3,2,6-dioxathiazocine 2-oxide. Oxidation of the four isomers by the use of KMnO4 yielded two kinds of sulfates. On the basis of the coupling constants and γ-effects, the stereochemical structures of the dioxathiazocine 2-oxides are discussed.
Preparation and Isomerization of 3,4-Bis(2,4,6-tri-t-butylphenylphosphinidene)cyclobutenes
Authors: Toyota Kozo , Tashiro Katsuya , Yoshifuji Masaaki , Nagase Shigeru
Published: July 2006

(E,E)- and (E,Z)-3,4-Bis(2,4,6-tri-t-butylphenylphosphinidene)cyclobutenes were prepared by desilylation reaction of the corresponding 1,2-bis(trimethylsilyl)cyclobutenes or by thermal isomerization reaction of 1,6-bis(2,4,6-tri-t-butylphenyl)-1,6-diphospha-1,2,4,5-hexatetraene. Optimized structures and total energies of various parent compounds C4H4P2 were calculated by ab initio method and the effect of steric congestion on the valence isomerization is discussed.
A New Bromo Diterpene, epi-Aplysin-20, and ent-Isoconcinndiol from the Marine Mollusc Aplysia kurodai
Authors: Ojika Makoto , Kigoshi Hideo , Yoshikawa Kohji , Nakayama Yoshisuke , Yamada Kiyoyuki
Published: July 2006

A New brominated labdane-type diterpene, epi-aplysin-20, and ent-isoconcinndiol have been isolated from the marine mollusc Aplysia kurodai: the structure of epi-aplysin-20 has been established on the basis of the spectroscopic data and chemical transformation.
Organic Synthesis Using Haloboration Reaction. XXI. A Synthesis of Prostaglandin B1 Methyl Ester by the Stepwise Cross-Coupling Reaction Using (E)-(2-Bromoethenyl)diisopropoxyborane
Authors: Hyuga Satoshi , Kara Shoji , Suzuki Akira
Published: July 2006

A prostaglandin B1(PGB1) analog and PGB1 methyl ester were synthesized by the palladium-catalyzed stepwise cross-coupling reaction of (E)-(2-bromoethenyl)diisopropoxyborane with (1-methoxy-1-hexenyl)zinc chloride and 3-bromo-2-cyclopenten-1-one derivatives. According to this method, the skeleton of PGB1 is prepared by the one-pot operation without isolation of any intermediates.
Structural Features of (CH3)2Si(C5H4)2Fe2(CO)3(C=NR) and (CH3)2Si (C5H4)2Fe2(CO)2(C=NR)2
Authors: Nakanishi Saburo , Taniki Yasushi , Otsuji Yoshio
Published: July 2006

The structure of isonitrile substituted diiron carbonyl complexes, (CH3)2Si(C5H4)2Fe2(CO)3(C=NR) (1) and (CH3)2Si(C5H4)2Fe2(CO)2(C=NR)2 (2) (R = t-butyl, cyclohexyl, and bornyl), in solution was studied by IR and NMR spectroscopy using variable-temperature and 2D NMR technique.
Attempted Transformation of 2,3,5,6-Tetrachloro-4,4-dimethoxypentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione toward Pentaprismane Retaining Chloro Group
Authors: Singh Vishwakarma , Furusaki Akio , Jaime Carlos , Matsumoto Takeshi , Osawa Eiji
Published: July 2006

An attempt towards synthesis of homohypostrophene derivative, 1,2,6,8-tetrachloro-7,7-dimethoxytetracyclo[6.3.0.02,6.05,9]undeca-3,10-diene from 2,3,5,6-tetrachloro-4,4-dimethoxypentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione is described.
Detection of Pitting on Cast Iron with AC Impedance Spectroscopy
Authors: Zhou Guo-Ding , Feng Yiqi , Fujishima Akira , Loo Boon H
Published: July 2006

The pitting behavior of high-chromium cast iron has been studied with AC impedance spectroscopy. When impedance measurements are carried out at open circuit potentials, it is observed at the initial stage of pitting that with increasing time, the polarization resistance R decreases for the better pitting resistant specimen, and increases for the poorer one. However, when the electrode potential is suitably fixed during the measurements, the R value shows an abrupt decrease at the initial stage for the sample with a poorer pitting resistance. This large change in the R value indicates the initiation of the pitting process and thus can be used for detecting such onset.
Volumetric and Thermal Behaviors of Water Uptaken in Superabsorbent Polymer
Authors: Manabe Masahiro , Ito Tetsuya , Kawamura Hideo , Kinugasa Takumi , Watanabe Kunio , Kagimoto Hisao
Published: July 2006

For the water uptaken in a superabsorbent polymer gel (Sumikagel) bearing polar groups (–COONa and –OH), the partial molar volume, heat of fusion, and melting point, have been determined over a wide region of water content, from water-free to a saturated state. The results indicate that the region can be classified into three characteristic parts. In the lowest water content region, the –COONa forms a monohydrate in the solid state. In the next region, the primary hydration of both groups and the dissociation of –COONa occur. In both regions the water is antifreezing. In the highest content region, secondary and higher hydration occurs; the hydrated water is freezing, and the so-called free water appears.
Hydrogen Bonding in Inclusion Complexes of Heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin with Chlorophenols in Organic Solvents
Authors: Hamai Sanyo
Published: July 2006

Heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMβCD) has been found to form inclusion complexes with p- and m-chlorophenol in organic solvents such as cyclohexane. In the inclusion complex, the guest p- or m-chlorophenol incorporated into the TMβCD cavity is hydrogen bonded to the host TMβCD. The equilibrium constants for the formation of the inclusion complexes of p- and m-chlorophenol with TMβCD in saturated hydrocarbons are an order of magnitude greater than those in water. The finding that the −ΔS values for the formation of the inclusion complex in saturated hydrocarbons are significantly greater than those in water suggests a rigid inclusion-complex structure which is reinforced by the hydrogen bond between the guest and TMβCD in saturated hydrocarbons.
Anion-Selective Field-Effect Transistor Sensor Using RF-Sputtering Film of Alkali Metal-Free Lead Phosphate Glass Containing Silver Oxide
Authors: Nomura Tsuyoshi , Masui Kanji
Published: July 2006

New ion-selective field-effect transistors (ISFET) for an anion responsive type probe are described. The gate surface of the ISFET was coated by radio-frequency sputtering with an alkali metal-free phosphate glass containing silver oxide. This ISFET responded to S2O32−, SCN−, I−, NO2−, SO32−, and Cl−, but not to NO3−, ClO3−, SO42−, and HPO42−. A radiation damage of sputtering products is generated in the dielectric layer and at the interface of the gate channel, and the static characteristics of the glass coated ISFETs were used to evaluate the radiation damage. Optimal RF sputtering gas composition, dc floating bias from anode to substrate, RF power density, and sputtering time were argon 90%/oxygen 10%, −70 V, 0.88 W cm−2, and up to 4 h, respectively.
Effect of Inhibitors on Azo-Reduction of 4′-Dimethylaminoazobenzene-2-carboxylic Acid by Clostridium Diaphorase
Authors: Yatome Chizuko , Fujimi Kazuhiko , Ogawa Toshihiko
Published: July 2006

The effect of inhibitors on the azo-reduction of 4′-dimethylaminoazobenzene-2-carboxylic acid (DMABC) by Clostridium diaphorase together with β-nicotinamide adenine dinucleotide, reduced form (NADH) has been investigated. The reduction was inhibited by o-aminobenzoic acid which is a reduction product of DMABC. Lineweaver–Burk plots indicated that o-aminobenzoic acid was a competitive inhibitor with respect to DMABC (Ki = 10.5 × 10−3 mol dm−3). Various monosubstituted benzoic acid derivatives were also competitive inhibitors, among which o-hydroxybenzoic acid was most effective.
Oxidative Substitution Reactions of Organostannyl Compounds with Lead Tetraacetate. A Convenient Route to 5-Alkylidene-2(5H)-furanones
Authors: Yamamoto Makoto , Munakata Hiroshi , Kishikawa Keiki , Kohmoto Shigeo , Yamada Kazutoshi
Published: July 2006

5-Substituted 2-tributylstannylfurans which were synthesized by the reaction of corresponding 5-substituted 2-lithiofurans with tributylstannyl chloride, were treated with two equimolar amounts of lead tetraacetate at room temperature to give corresponding 5-substituted 5-acetoxy-2(5H)-furanones in good yields. The 5-acetoxy-2(5H)-furanone was heated at 80 °C in acetic acid-acetic anhydride containing a catalytic amount of concentrated sulfuric acid to give 5-alkylidene-2(5H)-furanone in moderate yield.
Effects of Electron-Withdrawing Substituents on Bond Alternations in Pentalene and Heptalene
Authors: Kataoka Masahiro , Nakajima Takeshi
Published: July 2006

The bond alternations in pentalenes and heptalenes substituted by electron-withdrawing groups are studied by use of the Pariser–Parr–Pople–type SCF CI MO method and the symmetry rule for substituted conjugated hydrocarbons. The influence of electron-withdrawing substituents on geometrical structures of pentalene and heptalene markedly depends on the attached positions. The 2- and 5-substitutions in pentalene and the 1-, 3-, 5-, 6-, 8-, and 10-substitutions in heptalene increase the amount of positive charge and, at the same time, relax the bond alternations in the parent molecules. This relaxation correlates with the amount of the positive charge in the pentalene and heptalene skeletons. The large amount of positive charge brings about the stabilization of the delocalized structures. The critical values of positive charge for the existence of bond alternations are smaller than the unit positive charge. The substitutions at the other sites in both molecules are anomalous in the sense that they increase the amount of the positive charge but reinforce the bond alternations.
Reaction of Olefins with Dimethyl(methylthio)sulfonium Salts in the Presence of Triphenylphosphine. Preparation of Vinylphosphonium Salts
Authors: Okuma Kentaro , Koike Tetsufumi , Yamamoto Shin-ichi , Takeuchi Hiroshi , Yonekura Kazuki , Ono Masaaki , Ohta Hiroshi
Published: July 2006

Olefins were effectively converted into the corresponding (2-methylthioalkyl)triphenylphosphonium salts by the reaction with dimethyl(methylthio)sulfonium salts in the presence of triphenylphosphine. 2-Triphenylphosphonioalkyldimethylsulfonium salts, synthesized by alkylation of the corresponding methylthiophosphonium salts, react with 1,8-diazabicyclo[5.4.0]undec-7-ene or aq NaOH to afford the corresponding vinylphosphonium salts or vinylphosphine oxides in good yields.
N,N′-Di(8-quinolyl)glutaramide Exhibiting Highly Selective and Efficient Uphill Transport of Cu(II) through Liquid Membranes
Authors: Hiratani Kazuhisa , Kasuga Kazuyuki , Hirose Takuji , Taguchi Kazuhiro , Fujiwara Kyoko
Published: July 2006

N,N′-Di(8-quinolyl)glutaramide has been found to be an excellent Cu(II) carrier in the transport through a chloroform liquid membrane. It can selectively and efficiently transport Cu(II) from a weakly acidic aqueous solution containing Cu(II), Zn(II), Ni(II), and Co(II). Several N,N′-di(8-quinolyl)glutaramide derivatives and their analogues have been prepared for comparison of this transport ability, which largely depends not only upon the structure of the carriers, but also upon the transport conditions.
1H and 13C NMR Spectral Behavior and Isomerism in 7,12-Dimethyl-, 2,7,12-Trimethyl-, and 7,12,15-Trimethyl-8,10-bisdehydro[15]annulenones
Authors: Yamamoto Gaku , Higuchi Hiroyuki , Yamamoto Hiroyuki , Ojima Juro
Published: July 2006

Configurational and conformational isomerism in the bisdehydro[15]annulenones were studied in CDCl3 and CF3CO2D–CD2Cl2 solutions by 1H NMR spectroscopy. The 7,12-dimethyl compound with the initial “all-E” configuration isomerized in both media at ambient temperature to give an equilibrium mixture of isomers but the trimethyl derivatives retained their original configuration under the similar conditions. The charge distribution in the deuterated species was discussed on the basis of the 13C NMR spectra.
Structural Studies of Arylazo(α,α-dimethylbenzyl)malononitriles. Evidence against the Correlation between Bond Length and Reactivity in Bond Cleavage Reactions
Authors: Mitsuhashi Tsutomu , Yamamoto Gaku , Goto Midori , Kondo Yasuhiko
Published: July 2006

The X-ray structures of phenylazo(α,α-dimethylbenzyl)malononitrile and its p-MeO and p-NO2 derivatives were determined to examine the relationship between reactivity and ground state geometry. Although the rate of C–C bond heterolysis increases in the order p-MeO < H << p-NO2, neither systematic elongation of the C–C bond nor indication of other geometrical changes due to the interaction between the σ orbital of the bond and the π system of an arylazo group was observed on going from p-MeO to p-NO2. The results provide evidence against Kirby’s proposal of a direct relationship between reactivity and bond length, and support Arnett’s view that the stability of heterolysis products is not reflected in the bond length.
Preparation of a Lipid-Coated Lipase and Catalysis of Glyceride Ester Syntheses in Homogeneous Organic Solvents
Authors: Okahata Yoshio , Ijiro Kuniharu
Published: July 2006

A lipid-coated lipase was prepared by mixing aqueous solutions of lipase and dialkyl amphiphiles: A hydrophilic surface of the enzyme is covered with a lipid layer, of which lipophilic two-long-alkyl tails solubilize the enzyme in hydrophobic organic solvents. The lipid-coated lipase was prepared in various conditions by changing hydrophilic head groups of lipid molecules, a ratio of lipid/lipase, and an origin of lipase; the complex prepared from nonionic amphiphiles and lipase D from Rhizopus delemar showed a high stability and a high enzymatic activity in hydrophobic organic solutions. The lipid-coated lipase catalyzed di- and triacylglycerol syntheses from monoacylglycerols and aliphatic acids in the homogeneous and dry benzene solution in the presence of two pieces of molecular sieves (water: 80 ppm). The lipid-coated lipase could also catalyze ester exchange reactions in organic solvents with a small amount of water (250 ppm). Enzymatic activity was affected by a nature of organic solvents and a water content in organic solvents. The catalytic activity of the lipid-coated lipase was highly efficient compared with other enzyme systems such as the poly(ethylene glycol)-grafted lipase and the direct dispersion of lipase powder for glyceride syntheses in the dry organic solution.
Radical-Based Synthesis of Terpenoids. Stereoselectivity in the Trapping of Radicals from Cyclization of 3-(1-Ethoxy-2-haloethoxy)cyclohexenes
Authors: Nagano Hajime , Yamada Keiko , Hazeki Noriko , Mori Yukie , Hirano Tsuneo
Published: July 2006

Stereoselectivity in the intermolecular trapping of the bicyclic radical intermediates from cyclization of 3-(1-ethoxy-2-haloethoxy)cyclohexenes with methyl acrylate was found to be affected remarkably by the conformation of the radical intermediates. The optimized conformers of 8-methoxy-7-oxabicyclo[4.3.0]non-2-yl radicals, models for the radical intermediates, were obtained by PM3 RHF molecular orbital calculations, and the stereoselectivity was analyzed in detail.
Estimation of the Mechanism of Fused Aromatic Hydrocarbon Formation in Sooting Flames by Molecular Orbital Method
Authors: Sakaguchi Keizo , Fukutani Seishiro
Published: July 2006

Formation mechanism of fused aromatic hydrocarbons in a methane–air diffusion flame was investigated theoretically and experimentally. The reactivity of hydrocarbons taking part in the formation route was evaluated by means of the ab initio calculation of the molecular orbitals. The reactions of the formation route are classified into two groups: Reactions increasing the number of carbon atoms of hydrocarbon molecules and aromatic ring formation. The former reactions further consist of three steps: An attack of a hydrogen atom at a certain position of a hydrocarbon molecule, addition of an acetylene molecule at that position, and dehydrogenation. The position of the large frontier electron density is chosen as the reacting point of the first step. The formation of an aromatic ring can take place when the HOMO of the hydrocarbon and the LUMO of acetylene overlap each other. The above estimation gives the following reaction route of fused aromatic hydrocarbons in methane flames: acetylene → 1-buten-3-yne → benzene → ethynylbenzene → naphthalene → acenaphthylene, or naphthalene → 1-ethynylnaphthalene → phenanthrene. The predicted route was also supported by experimental results.
Simple Relationships between Coulson–Longuet–Higgins Polarizabilities in Linear Chains
Authors: Isihara Makoto
Published: July 2006

This paper describes general consequences of the hypervirial condition upon Coulson–Longuet–Higgins polarizabilities in the simple Hückel model of linear chains. The condition is put into the form of a tractable formula by introducing the modified polarizability; many simple relationships between polarizabilities are obtained through the formula. The relationships are often instructive conceptually, reflecting some characteristics of the Hückel model of linear chains, besides being helpful for numerical estimation of polarizabilities.
Temperature and Pressure Effects on the Reversible Reaction of a Parent Phenol (GH) Corresponding to Galvinoxyl with Aliphatic Amines
Authors: Nishimura Norio , Iga Siroh , Satoh Masahiro , Yamamoto Shunzo
Published: July 2006

The effects of temperature and pressure on the reversible reaction between GH and aliphatic amines in acetonitrile have been studied spectrophotometrically. The formation of free ions rather than that of ion pairs has been confirmed by the modified Benesi-Hildebrand (B–H) plot. From the plot the equilibrium constants were estimated. From the temperature dependence of the equilibrium constant (K), the heat and entropy of reactions were estimated to be: (ΔH°)av = −44.5 kJ mol−1, and (ΔS°)av = −193 J K−1 mol−1. From the pressure dependence of K the reaction volume (ΔV°)av was estimated to be −40 dm3 mol−1. When unbranched primary amines were used, a side reaction took place for which an explanation has been given.
ESR Spectra of Some Allene Radicals in Low-Temperature Matrices
Authors: Kubozono Yoshihiro , Ujita Hiroki , Okada Makoto , Ata Masafumi , Matsuda Yoshihisa , Gondo Yasuhiko
Published: July 2006

ESR spectra of the radicals of allene (1,2-propadiene) derivatives generated by 60Co γ-ray irradiation in halocarbon matrices have been observed at low temperatures. The geometrical structures of the radicals have been determined from the experimental ESR spectra and with the aid of semiempirical MO calculations invoking the UHF-AM1 and UHF-MNDO methods. After exposure of the allene derivatives to 60Co γ-ray in some halocarbon matrices at 77 K, the temperature raising gave rise to neutral radicals such as allylic and/or deprotonation-type radicals; these thermal reactions have been investigated in detail.
Time-Resolved Infrared Emission Studies of CO2 Formed by Catalytic Oxidation of CO on Pt and Pd Surfaces
Authors: Kunimori Kimio , Haller Gary L
Published: July 2006

Time-resolved FTIR emission spectroscopy was used to detect vibrationally excited gas phase CO2 formed by the catalytic oxidation of CO on Pt and Pd surfaces. A continuous molecular beam of O2 and a pulsed flux of CO (200 μs FWHM) were supplied to the surface at 900 K, and the infrared emission of the CO2 product was analyzed with 30 μs time resolution to study the dependence of the internal energy on surface oxygen coverage. Analysis of the band width and centroid of the time-resolved infrared spectra (4 cm−1 resolution) allows an estimation of the rotational and average vibrational temperatures (TR and TV ) of the CO2 molecules. At a low CO nozzle pressure on a Pt surface, the infrared signal intensity almost parallels the time dependent CO flux to the surface with relatively small changes in the infrared spectra. The analysis showed that both TV and TR decrease with decreasing surface oxygen coverage and that the change in TR is more significant than that in TV. At a high CO nozzle pressure, the reaction can be shut off as the oxygen on the Pt surface is depleted (CO titration behavior). These infrared spectra showed large changes in TV (from ca. 1700 K to 700 K). In contrast, on a Pd surface no drastic change in TV was observed even at high CO pressure, but TV was decreased slightly with decreasing surface oxygen coverage. The TV values (around 2000 K) on Pd are much higher than on Pt.
A New Annulation Reagent, 2-Oxo-3-alkenylphosphonates. Reactions with Carbonyl-Stabilized Carbanions or Silyl Enol Ethers Leading to Cyclohexenones
Authors: Wada Eiji , Funakoshi Junji , Kanemasa Shuji
Published: July 2006

The reactions of 2-oxo-3-alkenylphosphonates with carbonyl-stabilized carbanions directly lead to 2-cyclohexen-1-ones through a sequence of Michael reaction and intramolecular Horner–Emmons olefination. On the other hand, the Lewis acid-mediated reactions with silyl enol ethers produce 1,5-diketones as Michael adducts, which then undergo cyclization on treatment with sodium hydride or triethylamine/zinc (II) bromide to afford 2-cyclohexen-1-ones or 2-phosphinyl-2-cyclohexen-1-ones, respectively.
Thermal Transformation of a Layered Double Hydroxide Pillared with Decavanadate Isopolyanions
Authors: Lopez Salinas Esteban , Ono Yoshio
Published: July 2006

V10O286− anions, intercalated by anion-exchange into the interlayer gallery of a Mg–Al layered double hydroxide, undergo chemical transformation and reduction in the valence state when subjected to thermal treatment. XRD and IR analyses indicate that V10O286− breaks up into smaller species at 473 K, which then rearrange to form polymeric vanadate species of the type [–VO3–]nn− at 573–623 K. Concomitant with the disarrangement of the decavanadate anion, reduction of V(V) to V(IV) species takes place even when heat treated under air, as evidenced by ESR analysis. The number of V(IV) species increased steadily from 2.4 × 1018 to 2.2 × 1019 spin g−1 when the temperature of heat treatment rose from 393 to 473 K. Higher temperatures decreased gradually the number of V(IV).
Synthesis and Chemiluminescence Properties of 6-(4-Methoxyphenyl)-2-methylimidazo[1,2-a]pyrazin-3(7H)-one and 2-Methyl-6-(2-naphthyl)imidazo[1,2-a]pyrazin-3(7H)-one
Authors: Toya Yoshiaki , Kayano Toshimasa , Sato Kyoko , Goto Toshio
Published: July 2006

New Cypridina luciferin analogues, 6-(4-methoxyphenyl)-2-methylimidazo[1,2-a]pyrazin-3(7H)-one (MCLA) and 2-methyl-6-(2-naphthyl)imidazo[1,2-a]pyrazin-3(7H)-one (NCLA), were prepared together with their oxyluciferin analogues, 2-acetamido-5-(4-methoxyphenyl)pyrazine (MCOLA) and 2-acetamido-5-(2-naphthyl)pyrazine (NCOLA). Various chemiluminescence properties of these compounds were compared with those of known luciferin analogues, 2-methyl-6-phenylimidazo[1,2-a]pyrazin-3(7H)-one (CLA) and 6-(3-indolyl)-2-methylimidazo[1,2-a]pyrazin-3(7H)-one (ICLA). The light yields obtained from ICLA, MCLA, and NCLA were much higher than CLA in diethylene glycol dimethyl ether (diglyme), in which triplet oxygen was the oxidant. In aqueous solution, employing superoxide ion as the oxidant, NCLA emitted light weaker than CLA and MCLA. ICLA gave almost no light on account of no fluorescence intensity of the emitter (oxyluciferin analogue ICOLA) in aqueous solution. For applications to the detection of active oxygen species produced during enzymatic reactions, MCLA is superior to conventionally used CLA because of its higher chemiluminescence quantum yield and its emission maximum in visible region.
The Reactions of Nitrile Oxide–Quinone Cycloadducts. I. Base-Induced Rearrangement of the 1 : 1 –C=C– Adducts of Aromatic Nitrile Oxides with Dialkyl-Substituted p-Benzoquinones
Authors: Shiraishi Shinsaku , Holla B Shivarama , Imamura Kiyoshi , Inoue Yukihiko
Published: July 2006

The 1,3-dipolar cycloadducts, 9-aryl-7-oxa-8-azabicyclo[4.3.0]nona-3,8-diene-2,5-diones, which were obtained from the reactions of aromatic nitrile oxides with dialkyl-substituted p-benzoquinones, underwent an interesting rearrangement on the action of bases. The reactions exhibited incomprehensible substituent effect. The structure elucidation of the rearranged products and the reaction mechanism are described and discussed.
The Reactions of Nitrile Oxide-Quinone Cycloadducts. II. The Reactions of 2,5-Di-t-butyl-p-benzoquinone with Nitrile Oxides: 1 : 2 Cycloaddition and Base Induced Ring Transformation of the Cycloadducts
Authors: Inoue Yukihiko , Ambekar Salvottam Y , Xu Xiao-Hong , Shiraishi Shinsaku
Published: July 2006

The reactions of 2,5-di-t-butyl-p-benzoquinone with p-substituted benzonitrile N-oxides successfully gave 1 : 2 cycloadduct. The cycloadducts were proved to undergo base induced reactions in different patterns with aqueous sodium hydroxide or with triethylamine. Sodium hydroxide caused cleavage of cyclohexanedione ring to give γ-keto carboxylic acid derivatives, which take γ-hydroxy lactone form in solid state. On the other hand, triethylamine caused isoxazoline ring transformation reaction with elimination of one t-butyl group to give bis(isoxazole)-fused hydroxycyclohexadienone derivatives. The structure determination and the reaction mechanism are discussed.
Preparation and Properties of Clays Pillared with SiO2–TiO2 Sol Particles
Authors: Yamanaka Shoji , Inoue Yasushi , Hattori Makoto , Okumura Fumio , Yoshikawa Mikio
Published: July 2006

The silicate layers of montmorillonite clay were pillared with SiO2–TiO2 sol particles. Although only the SiO2 sols were negatively charged, the SiO2–TiO2 mixed oxide sols were positively charged and could be ion-exchanged with the interlayer cations of montmorillonite. The resulting pillared clays had a basal spacing expanded to more than 40 Å; the spacing was maintained during calcination up to 773 K. The adsorption properties of the calcined samples were studied for nitrogen as well as organic vapors. A structural model for the arrangement of the intercalated sol particles is proposed in which small SiO2–TiO2 sol particles are packed between the silicate layers. Micropores with a slit width of 10–12 Å are formed in the interstices between the sol particles and the silicate layers.
Selective Hydrogenation of Carbon Dioxide to Methanol on Cu–ZnO/SiO2 Catalysts Prepared by Alkoxide Method
Authors: Okabe Kiyomi , Sayama Kazuhiro , Matsubayashi Nobuyuki , Shimomura Kin’ya , Arakawa Hironori
Published: July 2006

Hydrogenation of CO2 to methanol was carried out on Cu–ZnO/SiO2 catalysts at 493 K and 3 MPa with a flow rate of 100 cm3 min−1 (H2/CO2 = 2). Higher selectivity ( > 90%) was observed on the catalysts prepared by the alkoxide method than on a conventional catalyst prepared by the impregnation method. The selectivity was higher on the catalysts pretreated with H2 at a higher temperature, except at 873 K. The activity of the catalyst pretreated at 873 K was extremely low, probably because of alloy formation. The results of XRD, XPS, and EXAFS demonstrate that the active species for methanol formation is a large metallic Cu particle covered with a partially oxidized layer interacting with highly dispersed ZnO.
Crystal Structure of (ImH)[Ni(dmit)2]2 with Intercolumnar Interaction through an Imidazolium Counter Ion
Authors: Miyazaki Akira , Izuoka Akira , Sugawara Tadashi
Published: July 2006

In the crystal of semiconductive salt, (ImH)[Ni(dmit)2]2 (ImH = imidazolium, H2dmit = 4,5-dimercapto-1,3-dithiol-2-thione), Ni(dmit)2 molecules are dimerized and stacked in columns, with two types of intercolumnar interaction through an imidazolium counter cation. One is based on three-centered S···NH···S type hydrogen bonds, and the other is van der Waals contacts between imidazolium cation and dmit ligand.
Polymers Having pH-Buffering Capability for Potential Use as Solid-Phase Reagent
Authors: Nakano Koji , Moriguchi Isamu , Ohishi Syunya , Takagi Makoto
Published: July 2006

Macroreticular styrene–divinylbenzene copolymeric resins were functionalized with aliphatic amine moieties and carboxylato groups. Their acid dissociation properties were studied with potentiometric method. Due to the acid-base properties of the incorporated functional groups, the resins obtained showed pH-buffering abilities covering the range of pH 4–9 to be useful as solid-phase reagents.
Solvent Extraction and Association of Nitrophenols with Trioctylphosphine Oxide in Cyclohexane
Authors: Kusakabe Satoshi , Ogihara Yasushi , Sekine Tatsuya
Published: July 2006

Extraction of phenol and nitrophenols into cyclohexane and association of these phenols with trioctylphosphine oxide (TOPO) in the organic phase were investigated at 298 K. A linear relation was found between the logarithm of the partition coefficient of the phenols and the logarithm of their association constant with TOPO.
Extractive Separation of Trace Amounts of CuII, FeIII, and GaIII from AIII on the Basis of HSAB Rule
Authors: Kawamoto Hiroshi , Nishimura Tohru , Tsunoda Kin-ichi , Akaiwa Hideo
Published: July 2006

The design of a separation scheme for CuII, FeIII, and GaIII from AIII by chelate extraction was proposed on the basis of the HSAB rule. Among the various chelating agents, 8-quinolinol was estimated to be the most effective for separation. This prediction was confirmed through experiments.
Phase Separation of Phosphotellurite Glass Investigated by 57Fe-Mössbauer Spectroscopy and DTA
Authors: Nishida Tetsuaki , Yamada Miho , Takashima Yoshimasa
Published: July 2006

The isomer shifts (δ) of xP2O5·(95−x)TeO2·5Fe2O3 glasses (x = 0–28), 0.38–0.39 mm s−1, suggest that Fe3+ substitutes for Te4+ of TeO4 trigonal bipyramids. The δ’s of 0.42–0.43 mm s−1 obtained when 30 ≤ x ≤ 40 indicate that Fe3+ (Oh) is present at interstitial sites of PO4 tetrahedra in the phosphate-rich phase.
Prediction of pKa Vlaues of Alkylphosphonic Acids
Authors: Ohta Kyuji
Published: July 2006

The pKa values of unsubstituted and substituted alkylphosphonic acids in aqueous solution were found to have a good linear correlation with the electron densities of the phosphorus atom of the corresponding phosphonic acids, which are calculated using the PM3 method. This enabled us to predict the pKa values of this class of compounds.
Substituent Effects on the 13C and 15N NMR Spectra of p-Substituted Phenylacetonitriles
Authors: Kusuyama Yoshiaki
Published: July 2006

13C and 15N NMR spectra have been measured for fifteen p-substituted phenylacetonitriles. The substituent-induced chemical shift changes (SCS) of C-1 had an inverse trend, while SCS (15N) showed a normal trend. These SCS values were correlated by the normal substituent constant, σ0. The observation are consistent with a pi-polarization mechanism in which the C≡N bond is polarized by the p-substituted phenyl moiety.
Synthesis of Syzygiol; A Skin-Tumor Promotion Inhibitor
Authors: Sato Shingo , Obara Heitaro , Endo Akira , Onodera Jun-ichi , Matsuba Shigeru
Published: July 2006

Syzygiol, 3-hydroxy-2-(β-hydroxycinnamoyl)-5-methoxy-6,6-dimethyl-2,4-cyclohexadien-1-one (1) was synthesized via ceroptene (5).
The Base-Catalyzed H/D-Exchange of Anisole Moiety of Ruthenium Complex in Cooperation with Demethylation by Hydroxide Anion in Methanol-d4
Authors: Kimura Masaru , Morita Mitsunobu , Mitani Hideo , Okamoto Hideki , Satake Kyosuke , Morosawa Shiro
Published: July 2006

[Ru(η5-C5H5)(η6-arene A)]BF4 (arene A = nitrobenzene, m- or p-nitrotoluene, anisole, phenetole, m- or p-methylanisole) were quantitatively converted to pure [Ru(η5-C5H5)(η6-arene B)]BF4 (arene B = phenoxido-2d  m- or p-monodeuterated methylphenoxido) in the presence of excess KOH in CD3OD, whereas [Ru(η5-C5H5)(η6-anisole)] BF4 was quantitatively obtained by treatment [Ru(η5-C5H5)(η6-nitrobenzene)] BF4 with 1 equivalent KOH or CH3OK.
A Convenient Synthesis of Cationic Vinylidene and 1,2-Propadienylidene Iron Complexes by Photoreaction of [CpFe(CO)(dppe)]+BF4− with 1-Alkynes
Authors: Nakanishi Saburo , Goda Ken-ichi , Uchiyama Shin-ichi , Otsuji Yoshio
Published: July 2006

Photoreaction of [CpFe(CO)(dppe)]+BF4− with 1-alkynes proceeded to give cationic vinylidene and 1,2-propadienylidene iron complexes in good yields.
Partial Oxidation of Methane to Synthesis Gas over Rhodium Vanadate, RhVO4: Redispersion of Rh Metal during the Reaction
Authors: Kunimori Kimio , Umeda Shinichi , Nakamura Junji , Uchijima Toshio
Published: July 2006

Partial oxidation of methane to synthesis gas (CO+H2) has been carried out over both RhVO4/SiO2 and unpromoted Rh/SiO2 catalysts at temperatures between 300 °C and 720 °C and 1 atomosphere pressure, with a CH4 : O2 of 2 : 1 under nitrogen dilution. It is found that the RhVO4 compound supported on SiO2 was reduced to Rh metal and V2O3 during the reaction, and the catalyst showed onset of activity to CO and H2 around 500 °C reaching a maxium conversion in excess of 90% at 650 °C, while the unpromoted Rh/SiO2 catalyst showed the onset of activity at the higher temperature (above 600 °C) reaching almost 100% conversion at around 700 °C. The different catalytic activity may be ascribed to both the morphology change (Rh dispersion) and the Rh–vanadia interaction after the reduction of the RhVO4 compound.
Topochemical Reaction of 7-Bromoethoxycarbonyl-7-cyano-1,4-benzoquinone Methide in the Solid State
Authors: Itoh Takahito , Tachino Kyoko , Uno Takahiro , Kubo Masataka , Tohnai Norimitsu , Miyata Mikiji
Published: July 2006

Topochemically controlled [2 + 2] photocycloaddition took place at the quinoid double bond of the 7-bromoethoxycarbonyl-7-cyano-1,4-benzoquinone methide (1) to afford its cyclobutane dimer.
Construction of Strained Frameworks with 1,8-Anthrylene Units and Acetylene Linkers: Synthesis and Structures of Cyclic Trimers
Authors: Goichi Michio , Miyahara Hiroaki , Toyota Shinji
Published: July 2006

Two 1,8-anthrylene cyclic trimers with acetylene or diacetylene linkers were synthesized by macrocyclization with the Eglinton coupling. These compounds have nonplanar and strained cyclic structures with significant bending deformations of acetylene carbons as revealed by X-ray analysis and DFT calculation. The effects of the molecular structures on the 13C NMR chemical shifts and the electronic spectra are discussed.
A New Spectrophotometric Method for Determination of Urinary Protein Using Erythrosin B
Authors: Isoe Junichi , Kaneko Emiko
Published: July 2006

A new sensitive spectrophotometric method for human serum albumin (HSA), the main protein in urine, has been developed using Erythrosin B. The proposed method is not based on conventional spectral shift but on an enhanced absorbance of the protein–bound dye and suppression of reagent blank in the presence of Triton X-100. The detection limit for HSA is 0.06 mg L−1 (S/N = 3), which is superior to conventional methods by a factor of 50–100. This is the first ever spectrophotometric method applicable for urinary protein even in healthy subjects.
Population of 6-Enol Form is Higher in 8-Oxoguanine than in Guanine
Authors: Yoshida Tomoki , Aida Misako
Published: July 2006

We investigate the relative stabilities of tautomers of 8-oxoguanine (8OG) and guanine (G) comprehensively at various levels of theory up to MP4 and CCSD(T) in the gas phase. We find that the population of the enol form at C6 position in 8OG is higher than that in G at any level of theory which we used. This may partly account for the high mutagenicity of 8OG.
Exciplex Formation between Pyrene and N,N-Dimethylaniline in DNA for the Detection of One-base Deletion
Authors: Kashida Hiromu , Komiyama Makoto , Asanuma Hiroyuki
Published: July 2006

Exciplex emission from pyrene and N,N-dimethylaniline moieties was observed in aqueous solution by incorporating them into DNA. By using this exciplex formation, one-base deletion was successfully detected.
Observation of the New κ2C,O:κ2C′,O′ Coordination Mode of 1,1,2,2-Tetraacetylethanato Ligand in a Dinuclear 1,1,1,5,5,5-Hexafluoroacetylacetonato Palladium(II) Complex
Authors: Fukuda Yutaka , Sakumoto Maiko , Tanabe Yoshiaki , Ishii Youichi , Suzuki Wakako , Nakao Akiko
Published: July 2006

We have isolated a new dinuclear palladium(II) complex containing 1,1,2,2-tetraacetylethanato (taet) and 1,1,1,5,5,5-hexafluoroacetylacetonato (hfac) ligands, [(hfac)Pd(C,O-taet)Pd(hfac)] (2b), whose crystallographic study has revealed that taet is coordinated to each palladium center as a κ2C,O ligand to form a five-membered chelate ring. Complex 2b provides the first example of the κ2C,O:κ2C′,O′ coordination mode of β-diketonato ligand, which slowly tautomerizes to [(hfac)Pd(O,O-taet)Pd(hfac)] (2a).
Thin Film Characteristics and FET Performances of β-Octyl-substituted Long Oligothiophenes
Authors: Takimiya Kazuo , Sakamoto Katsuhiro , Otsubo Tetsuo , Kunugi Yoshihito
Published: July 2006

A series of β-octyl-substituted oligothiophenes from 6-mer to 41-mer was examined for active layers of organic filed-effect transistors. Upon spin-coating from chloroform solution, the 20-mer and the longer oligomers formed homogenous thin films composed of stacked lamella structures. Top-contact devices fabricated using these films showed good p-channel FET characteristics with mobilities of 10−3 cm2 V−1 s−1 which gradually increase with the extension of chain length.
Planning abilities and chess: A comparison of chess and non‐chess players on the Tower of London task
Authors: Unterrainer J. M. , Kaller C. P. , Halsband U. , Rahm B.
Published: July 2006

Playing chess requires problem‐solving capacities in order to search through the chess problem space in an effective manner. Chess should thus require planning abilities for calculating many moves ahead. Therefore, we asked whether chess players are better problem solvers than non‐chess players in a complex planning task. We compared planning performance between chess (N=25) and non‐chess players (N=25) using a standard psychometric planning task, the Tower of London (ToL) test. We also assessed fluid intelligence (Raven Test), as well as verbal and visuospatial working memory. As expected, chess players showed better planning performance than non‐chess players, an effect most strongly expressed in difficult problems. On the other hand, they showed longer planning and movement execution times, especially for incorrectly solved trials. No differences in fluid intelligence and verbal/visuospatial working memory were found between both groups. These findings indicate that better performance in chess players is associated with disproportionally longer solution times, although it remains to be investigated whether motivational or strategic differences account for this result.
Does hunger influence judgments of female physical attractiveness?
Authors: Swami Viren , Tovée Martin J.
Published: July 2006

To account for male preferences for female body weight following a consistent socio‐economic pattern, Nelson and Morrison (2005) proposed a social‐cognitive model based on the individual experience of resource scarcity. We replicated their studies showing that calorific dissatisfaction can influence preference for female body weight using a different dependent variable, namely photographic stimuli of women with known body weight and shape. Using this revised methodology, we found that operationalized intra‐individual resource scarcity affects preferences for body weight: 30 hungry male participants preferred figures with a higher body weight and rated as more attractive heavier figures than 31 satiated male participants. Hungrier men were also less likely to be influenced by cues for body shape, supporting extant cross‐cultural studies on female physical attractiveness. These findings corroborate those of Nelson and Morrison (2005) and are discussed in terms of how cultural contexts shape individual psychological experience as predicted by the theory of mutual constitution.
Public-private sector partnerships in an agricultural system of innovation: Concepts and challenges
Authors: Hall Andy
Published: July 2006

The potential for publicprivate sector partnerships is likely to grow. However, despite a number of high-profile success stories, promoting partnerships has proved more difficult than many assumed. This article argues that such partnerships need to be viewed in the framework of an innovation
system and a development scenario where networks of local agro-enterprises will underpin rural development and poverty reduction. This view helps reveal the importance of embedding public research organizations within these local networks and highlights the fact that constraints to building
partnership is institutional in nature i.e. it relates to habits, practices and patterns of trust. The article concludes by suggesting that efforts should be focused on building social capital in agricultural innovation systems and cautioning that this should be done in contextually relevant
ways.
Continuous innovation in a complex and dynamic environment: The case of the Australian health service
Authors: Davison Graydon , Hyland Paul
Published: July 2006

Previous research on the management competences and organisational capabilities necessary for continuous innovation in complex and dynamic environments and evidence emerging from a study of innovation in palliative care are compared. A range of research on the management of different types of innovation within changing contexts is presented along with research on the relationships between management competence, organisational capabilities and innovation choices. Evidence is presented from research into innovation management in palliative care that enables a relationship between some elements of the theory and practice of innovation management in complex and dynamic environments to be established.
Intranet et changement organisationnel: cas d'entreprises du secteur de crdit bail en Tunisie
Authors: Bradai Wafa , Chaabouni Jamil
Published: July 2006

The introduction of the intranet may constitute a lever of organizational changes. This article deals with the identification of the effects of intranet introduction on the organization, particularly its two aspects: structure and process. The survey that was carried out on Tunisian
leasing companies shows that the impact of intranet introduction on the structure and the process of credit provision are variable. Some similarities and differences between the cases studied are noted. The impact depends on the type of intranet implemented. Despite the intranet's role in
enhancing the operation of enterprises, it does not appear to involve substantial organizational changes. On the contrary, the results of recent studies carried out in industrialized countries show enterprises integrating the intranet into their management system. Whatever the trajectory followed
by the firms to integrate the intranet, the issue here is the distribution of resources and knowledge between members of the organization.
Online Posture Correction for Humanoid Walking Robots (Online Haltungskorrektur für humanoide Laufroboter)
Authors: Wollherr Dirk
Published: July 2006

An online posture modification method termed Jacobi Compensation is proposed which is suitable to modify precalculated step trajectories for a humanoid robot in certain task coordinate directions. This method can account for modeling errors in trajectory precalculation by shifting e. g. the center of mass or certain parts of the humanoid mechanism to increase walking equilibrium and performance. A theoretical analysis of stability properties is given.
Descriptor Systems: A General Mathematical Framework for Modelling, Simulation and Control (Deskriptorsysteme: Ein allgemeines mathematisches Konzept für Modellierung, Simulation und Regelung)
Authors: Mehrmann Volker , Stykel Tatjana
Published: July 2006

Descriptor systems present a general mathematical framework for the modelling, simulation and control of complex dynamical systems arising in many areas of mechanical, electrical and chemical engineering. This paper presents a survey of the current theory of descriptor systems, concerning solvability, stability, model reduction, controllability, observability and optimal control.