bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanochemical Decomposition of Dipotassium Peroxodisulfate by Dry Grinding
Authors: Motooka Itaru , Nariai Hiroyuki , Tsuhako Mitsutomo 
Published: July 2006

Abstract
The mechanochemical decomposition of dipotassium peroxodisulfate by dry grinding was investigated by X-ray diffractometry, infrared spectrophotometry, electron spin resonance (ESR) spectrometry, and thermal and volumetric analyses. When dipotassium peroxodisulfate (K2S2O8) was ground, type I of K2S2O8 was transformed into type II and then into type III. With prolonged grinding, the O–O linkage in K2S2O8 was severed to produce KSO4· radicals, which reacted with a little moisture to give KHSO4.
The Determination of 5-Iodouracil Using the o-Hydroxyhydroquinonephthalein–Palladium(II) Complex
Authors: Fujita Yoshikazu , Mori Itsuo , Kitano Shoko 
Published: July 2006

Abstract
A simple and sensitive spectrophotometric procedure was studied for the determination of 5-iodouracil (IU) using the o-hydroxyhydroquinonephthalein(Qn.Ph.)–palladium(II) complex and avoiding any effect of iodide ions. This method could be used in the concentration range of 0–15 μg/10 ml of IU, where the Sandell sensitivity was 0.0020 μg/cm2 for at 630 nm; the coexistence of the iodide ion did not interfere with the determination of IU, even when it was present in a 500-fold excess.
The Stereochemistry of Cross-coupling Adducts of Norbornenes with Butadiene Catalyzed by Ni Complex
Authors: Ishii Yasutaka , Kawahara Masakazu , Noda Toshimitsu , Ishigaki Hiroyuki , Ogawa Masaya 
Published: July 2006

Abstract
The stereochemistry of cross-coupling adducts of norbornenes with butadiene catalyzed by Ni complex generated in situ by NiBr2(Ph3P)2 and NaBH4 in ethanol was investigated. The configuration of four-member cross coupling products could be confirmed by means of independent synthesis.
Synthesis of Lepiochlorin, a Chlorinated Antibiotic, by Use of Electrochemical Haloalkoxylation
Authors: Torii Sigeru , Inokuchi Tsutomu , Kondo Kazumi 
Published: July 2006

Abstract
The fungal metabolite lepiochlorin was synthesized from 2-methyl-4-oxopentanoic acid by the electrochemical chloromethoxylation of 2-methyl-2,4-pentadien-4-olide in MeOH–NH4Cl–(Pt–Pt) system followed by hydrolysis in a mixed solution of dioxane–H2O–concd HCl (25/10/1 V/V/V) in 38% overall yield.
Hydrolysis of p-Nitrophenyl Esters by Hydrophobic Linear Molecule Containing Two Histidine Residues
Authors: Kodaka Masato 
Published: July 2006

Abstract
A new type of linear nucleophile, CH3O–His–CO–(CH2)8–CO–His–OCH3(HisC8His), was designed, and its catalytic behavior for the hydrolysis of p-nitrophenyl acetate, hexanoate and laurate was investigated. It was shown that HisC8His enhanced the hydrolysis of p-nitrophenyl laurate and hexanoate as compared with imidazole both in the absence and presence of methyltrioctylammonium chloride.
An NMR Study on Molecular Interactions in 3-Methylsydnone and Its Aqueous Mixtures
Authors: Tanaka Shoji , Yokoi Masatoki 
Published: July 2006

Abstract
Molecular motion in neat 3-methylsydnone and molecular interaction in 3-methylsydnone–water mixtures were studied by the multinuclear FT-NMR method. The estimated rotational correlation times of the methine carbon and the carbonyl oxygen atom in neat sydnone are 8.6 and 8.1 ps at 40 °C, respectively. According to shift variations of the 13C, 14N, and 17O nuclei of the sydnone molecule in sydnone–water mixtures, the sydnone forms a hydrogen bond with water at the carbonyl oxygen and not at the ring oxygen site. The effect of dissolved paramagnetic ions was investigated on the 13C spin-lattice relaxation time of the carbon atoms of sydnone, and a discussion was made on the possible relative configuration of cation and anion to the solvent sydnone molecule.
One-electron Oxidation Potentials of an NADH Model Compound and a Dimeric Rhodium(I) Complex in Irreversible Systems. A Convenient Determination from the Fluorescence Quenching by Electron Acceptors
Authors: Fukuzumi Shunichi , Hironaka Katsuhiko , Nishizawa Nobuaki , Tanaka Toshio 
Published: July 2006

Abstract
A new methodology for experimental determinations of redox potentials of oxidants or reductants in both reversible and irreversible systems is presented. The Rehm-Weller free energy relationship between the activation free energy ΔG− and the free energy change ΔG for the electron transfer quenching of the excited states of oxidants or reductants by a series of reductants or oxidants is converted to a linear correlation between ΔG\eweq−ΔG and (ΔG\eweq)−1, which can be utilized in convenient determinations of redox potentials of oxidants or reductants. This methodology is established in various reversible systems where the redox potentials of oxidants or reductants determined based on the Rehm-Weller free energy relationship agree well with those determined independently by electrochemical methods. By using this method, one-electron oxidation potentials of two quite different compounds, one is an NADH model compound, 1-benzyl-1,4-dihydronicotinamide (BNAH), and the other [Rh2(dicp)4]2+ (dicp=1,3-diisocyanopropane), in MeCN have been determined as 0.60±0.10 and 0.38±0.10 V vs. SCE, respectively. The relation between the oxidation potential and the oxidation peak potential of BNAH measured by the cyclic voltammetry is discussed in the context of free energy relationships.
Electronic Relaxation Processes from Single Vibronic Levels in the S1(n, π*) State of Pyridine Vapor
Authors: Sushida Kazuyoshi , Fujita Masahisa , Yamazaki Iwao , Baba Hiroaki 
Published: July 2006

Abstract
The rate constants of radiative decay (kF), internal conversion (kIC), and intersystem crossing (kISC) for single vibronic levels in the S1(n, π*) state of pyridine-d0 and -d5 vapors have been determined from measured fluorescence quantum yields (ΦF), intersystem crossing quantum yields (ΦICS), and picosecond fluorescence lifetimes. The ΦISC values are fairly constant in the region of lower excess vibrational energy (&lt;1000 cm−1), while the ΦF values are particularly large for vibronic levels involving non-totally symmetric vibrations, ν16b and ν10a. The latter observation is attributed to both an increase of kF and a decrease of kIC and kISC (relative to the zero-point level) for the ν16b levels (16b2 and l6b26a1), and to an increase of kF for the ν10a levels. The relative values of kF are discussed using the Herzberg-Teller theory of vibronic coupling. The values of kF for 16b1 and 16b2 are significantly larger than that for the zero-point level, though no absorption band corresponding to 16b01 can be observed. In both pyridine-d0 and -d5, the value of kIC is as large as 1.7×1010s−1 even for the zero-point level, which is more than twice the kISC value for the same level.
Fractional Spectrophotometric Determination of Ethylenediaminetetraacetate and nitrilotriacetate as Their Iron(III) Complexes by Use of H- and Na-form Ion Exchange Resin Columns
Authors: Yamaguchi Akihiro , Ohzeki Kunio , Kambara Tomihito 
Published: July 2006

Abstract
The fractional determination of ethylenediaminetetraacetate(EDTA) and nitrilotriacetate(NTA) was carried out by use of hydrogen- and sodium-form ion exchange resin columns. After the conversion of free and complexed EDTA and NTA to the corresponding iron(III) complexes, two aliquots of the sample solution were separately passed through the columns. The iron(III)–EDTA complex was stable in both columns but iron(III)–NTA complex was completely decomposed in the hydrogen-form resin column, therefore, both of iron(III)–EDTA and –NTA were found in the effluent of sodium form resin column but only iron(III)–EDTA was found in the effluent of hydrogen-form resin column. The complexes in the respective effluents were determined spectrophotometrically at 255 nm. The recovery tests of EDTA and NTA from the synthetic sample solutions containing various metal ions were examined and the results observed were satisfactory.
Synthetic Studies on the Validamycins. VIII. Synthesis of Dl-2-Deoxyvalidoxylamine B and Related Compound
Authors: Ogawa Seiichiro , Ito Hiroyuki , Suami Tetsuo 
Published: July 2006

Abstract
Dl-2-Deoxyvalidoxylamine B and its diastereomer have been synthesized by the reaction of the protected Dl-valienamine and the anhydro derivative of (hydroxymethyl)cyclohexanetetrol followed by removal of the protecting groups.
Nonequilibrium Thermodynamics of the Ion and Solvent Transports through Ion-exchange Membrane
Authors: Kimizuka Hideo , Nagata Yoshihiko , Kaibara Kozue 
Published: July 2006

Abstract
A theory for the ion and solvent transports through membrane has been developed on the basis of nonequilibrium thermodynamics. The fluxes were represented as linear functions of the effective driving potentials. The theory is reduced to that of Katchalsky when the concentration ratio of two aqueous solutions is near unity and the solutions are dilute. The effect of solvent flow on the interionic correlations was discussed. It was pointed out that Despic and Hills’ theory of the electroosmotic effect on the membrane conductance is not valid with respect to both theoretical and experimental aspects. The comparison of the present theory with the previous one was also made. The six independent phenomenological coefficients (elements of the conductance matrix) were experimentally determined as a function of concentration with the concentration cell consisting of the amphoteric ion-exchange membrane and aqueous calcium chloride solutions. The membrane properties were discussed in terms of the conductance matrix. The diffusional ion conductance was much greater than the electrical ion conductance, as an indication of the failure of the Nernst-Einstein relation. The cation-anion coupling coefficient was close to unity whereas the ion-water coupling coefficients were less than 0.1. The solvent effects on the interionic conductance elements were found to be small in spite of the fact that the water permeability was extremely high. The distinction between the cationic and amphoteric ion-exchange membranes was explored in terms of the elements of the conductance matrix.
Electric Field Orientation of Poly(p-styrenesulfonate) and Its 9-Aminoacridinium Complex as Studied by Square-pulse Transient Electric Birefringence
Authors: Yamaoka Kiwamu , Ueda Kazuyoshi 
Published: July 2006

Abstract
Electric birefringence was measured at 20 °C and at 535 nm for sodium poly(p-styrenesulfonate) (NaPSS), with and without added sodium chloride, and the 9-aminoacridinium (AA) complex in aqueous solutions. The field strength dependence of both the steady-state EB (Δn(∞)) the field-free decay time (〈τ〉EB) was examined. Charge suppression by added Na+ ions or neutralization by strongly bound AA decreased both Δn(∞) and 〈τ〉EB considerably, altering not only the optical factor Δg and electric moments, but also the backbone chain length. The weight-average values of chain length (lw), pseudopermanent dipole moment (μw), counterion-induced electric polarizability anisotropy (Δαw), and the length-independent values of Δg were estimated by analyzing the experimental data on the basis of the “classical” orientation function which takes into account the continuous distribution of chain length for the polydisperse NaPSS sample. The electric field orientation of NaPSS and the AA-complex could be described by the interaction between an applied field and the electric moment which transforms from counterion-induced type in the extremely low field region (&lt;1.5 kV/cm) to saturated induced permanent type at higher fields.
Potentiometric and Calorimetric Studies on the Formation of Ethylenediamine Complexes of Nickel(II) Ion in Water and Dioxane–Water Mixtures
Authors: Ishiguro Shin-ichi , Oka Yoshihiro , Ohtaki Hitoshi 
Published: July 2006

Abstract
Equilibria between ethylenediamine and protons or nickel(II) ions have been investigated at 25 °C by means of potentiometric and calorimetric titrations in water and in dioxane–water mixtures (the dioxane contents are 0.1 and 0.2 mole fractions, which correspond to 35.2 and 55.0%w/w, respectively) containing 3 mol dm−3 LiClO4 as a constant ionic medium. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) referring to the formation of the species HL+, H2L2+, NiL2+, NiL22+, and NiL32+ (L denotes ethylenediamine) have been determined in the solutions. All the formation constants of the nickel(II)–ethylenediamine complexes increased with increasing dioxane content in the solvent mixtures, although the formation constants of the ethylenediammonium ions remained practically unchanged. On the other hand, enthalpies referring to the formation of the nickel(II)–ethylenediamine complexes became less negative, and thus entropies for the corresponding reactions increased remarkably with increasing dioxane content in the mixtures. The solvent effects on the thermodynamic parameters of the complex formation of nickel(II) ions with ethylenediamine are discussed in terms of enhancement of solvation of the complexes due to weakening of the hydrogen-bonded structure of the bulk water by the addition of dioxane.
The Cycloaddition Reaction of N-Imidoyl Sulfoximides with Diphenylcyclopropenone to Yield Pyrimidinone or Pyrrolinone Derivatives
Authors: Yoshida Hiroshi , Sogame Shingo , Takishita Yasunori , Ogata Tsuyoshi 
Published: July 2006

Abstract
N-Imidoyl sulfoximide (7) reacted with diphenylcyclopropenone (2) at 130 °C to yield a mixture of 1,2-disubstituted 5,6-diphenyl-4(1H)-pyrimidinone (6) and N-(4-oxo-2-pyrrolin-5-yl)sulfoximide (10), which might be formed by [3+3] and [2+3] cycloaddition reactions between 2 and 7. The yields of 6 and 10 depended on the electronic and steric effects of the substituents of 7.
The Recovery of Lithium from Geothermal Water in the Hatchobaru Area of Kyushu, Japan
Authors: Yanagase Kenjiro , Yoshinaga Tetsutaro , Kawano Kentaro , Matsuoka Toshikazu 
Published: July 2006

Abstract
The recovery of lithium from geothermal water at Hatchobaru in Kyushu, Japan, was investigated. A coprecipitation method using aluminium salts was employed. The lithium concentration in the geothermal water used in the present study was about 10 ppm. To make our experimental results more applicable for geothermal water, a reference lithium solution (10 ppm) was also studied as a control solution. A perfect recovery of lithium was obtained for the reference lithium solution by choosing appropriate conditions. For geothermal water, the yield of Li was not so good as in the control solution. However, an almost complete recovery of lithium was attained for geothermal water by the removal of calcium ions and polymerized silica. The mechanism of Li recovery was also considered.
X-Ray Structure of (10R)-10-Bromo-10-deoxyhexahydrolaurefucin
Authors: Furusaki Akio , Matsumoto Takeshi , Kikuchi Hajime , Suzuki Teruaki , Suzuki Minoru , Kurosawa Etsuro 
Published: July 2006

Abstract
The main product of the bromination of hexahydrolaurefucin with sulfinyl bromide has been established as (10R)-10-bromo-10-deoxyhexahydrolaurefucin by X-ray crystal structure analysis.
A New Apparatus for Surface Pressure Measurements
Authors: Iwahashi Makio , Middleton Steven R , Seimiya Tsutomu , Pethica Brian A 
Published: July 2006

Abstract
A new type of horizontal film balance is described. The principal features of the balance are the use of lightly paraffined silk threads without the conventional floating barrier of the Langmuir surface balance and of a strain gauge as the surface pressure detector.
Nitrosyl(protoporphyrin IX dimethyl ester)iron(II) Complexes with Nitrogenous Bases. The Basicity Dependence of the NO Stretching Frequency
Authors: Yoshimura Tetsuhiko 
Published: July 2006

Abstract
The IR spectra of nitrosyl(protoporphyrin IX dimethyl ester)iron(II) [Fe(ppdme)(NO)] complexes with various nitrogenous bases (B), such as imidazoles, pyridines, cyclic secondary amines, and aliphatic amines, were measured in benzene and 1,2-dichloroethane. The NO stretching frequencies (νNO) of these complexes and the equilibrium constants in equilibrium, [Fe(ppdme) (NO)]+B\ightleftharpoons[Fe(ppdme)(NO)B], decreased and increased respectively with an increase in the basicity, pKa(BH+), of the bases. These results are discussed in relation to the σ- and π-bonding abilities of the bases.
Synthesis and Magnetic, Spectral, and Electrochemical Properties of Strati-bis Cobalt(II) Complexes
Authors: Nakamura Masaaki 
Published: July 2006

Abstract
Strati-bis cobalt(II) complexes, [Co2(sata)]·2H2O and [Co2(sacta)] have been prepared, where H4(sata) and H4(sacta) denote 1,2,3,4-tetrakis(salicylideneamino)-2,3-dimethylbutane and 1,2-bis(salicylideneamino)-1,2-bis (salicylideneaminomethyl) cyclohexane, respectively. Since their magnetic moments are 4.89 and 4.73 BM at room temperature, respectively, the cobalt(II) ions in [Co2(sata)] and [Co2(sacta)] have a high spin d7 configuration. From the temperature dependence of magnetic susceptibilities of these complexes the antiferromagnetic interaction exists between the two cobalt(II) ions. The oxidation potentials for CoII→CoII are observed at lower potentials compared with those of corresponding mononuclear cobalt(II) complexes.
Induced Circular Dichroism in the Complex of Poly(l-arginine) Hydrochloride with Azo Dyes
Authors: Yamamoto Hiroyuki , Nakazawa Ayako 
Published: July 2006

Abstract
The induced circular dichroism (CD) spectra of the poly(l-arginine) hydrochloride–azo dye complexes were measured. The induced CD arose from the azo dyes bound to the polypeptide in the α-helical conformation. The configuration of the transition dipole moments of dye was examined by the exciton chirality method.
Diazomethane Ring-expansion of (−)-D3-Trishomocubanone. Preparation and Chiroptical Properties of a Series of [m.1.1]Triblattanes
Authors: Nakazaki Masao , Naemura Koichiro , Hashimoto Masaki 
Published: July 2006

Abstract
Optically active [3.1.1], [4.1.1], [5.1.1], and [6.1.1]triblattanes were prepared through the diazomethane ring-expansion of (−)-D3-trishomocubanone. The absolute molecular rotations of [m.1.1]triblattanes were found to increase with m begining from m=0 till m=2. On going from m=2 to m=3, [M]D abs. abruptly drops, then the value remains almost constant till m=6.
Surface Treatment of Inorganic Pigments by Nε-Acyllysine
Authors: Esumi Kunio , Yoshida Shigeki , Meguro Kenjiro 
Published: July 2006

Abstract
Inorganic pigments(calcium carbonate, iron oxide, and titanium dioxide) were treated with Nε-lauroyl-l-lysine, which is almost insoluble in both polar and nonpolar solvents. Two methods were employed for the treatment: (1) grinding of various weight proportional mixtures of pigment and the N-acyllysine; (2) adsorption of the N-acyllysine from its calcium ethylate solution on pigment. In method(1), the sufficient hydrophobic treatment was made when the weight percent of the N-acyllysine in the mixture was above about 30%. On the other hand, in method(2), although the amount adsorbed of the N-acyllysine was about in the range of 10−6 mol/g, the treated pigment showed a hydrophobicity. The critical surface tension of the treated samples estimated by using various mixtures of methanol and water was in the range from 23 to 39 dyn/cm.
The Selectivity Characteristics of Surfactant Ion-sensitive Nitrobenzene-membrane Electrode
Authors: Satake Iwao , Noda Shun-ichi , Maeda Tamaki 
Published: July 2006

Abstract
The selectivity coefficients of nitrobenzene-membrane electrode containing dodecyltrimethylammonium dodecyl sulfate as an ion exchanger were determined. For a homologous series of surfactant ions, the logarithm of the selectivity coefficient was found to increase linearly with increasing hydrocarbon chain length. The selectivity sequence for anionic surfactant ions with the same alkyl chain length became alkyl-benzenesulfonate ion&gt;alkyl sulfate ion&gt;&gt;alkanesulfonate ion, while that for cationic ones became alkyltrimethyl-ammonium ion≈1-alkylpyridinium ion&gt;&gt;alkylammonium ion. These results can reasonably be interpreted in terms of the partition coefficient of surfactant ion between aqueous and membrane phases. A tentative estimation based on the theory of liquid-membrane electrode led to −2900 J mol−1 for the standard free energy of transfer of a methylene group from water to nitrobenzene.
Raman Spectra in the Skeletal Vibration Region of [Co(gly)x(ox)y(en)z](3−x−2y)+ Complexes (x+y+z=3)
Authors: Maruyama Toshihide F , Okamoto Ken-ichi , Hidaka Jinsai , Einaga Hisahiko 
Published: July 2006

Abstract
The Raman spectra were measured for the complete series of cobalt(III) complexes, [Co(gly)x(ox)y-(en)z](3−x−2y)+, where gly, ox, and en denote glycinate, oxalate, and ethylenediamine, respectively, and x+y+z is equal to 3, in aqueous solution in the skeletal vibration region to deduce their structure-spectra relation. The spectra could be classified into four categories: polarized bands in the 610–520 cm−1 region due to a totally symmetric stretching vibration mode, depolarized bands in the 520–400 cm−1 region due to Co–O and Co–N stretching vibration modes, depolarized bands in the 400–300 cm−1 region due to the metal-ligand skeletal bending deformation mode, and polarized bands in the 300–200 cm−1 region due to the chelate ring deformation mode. The depolarized bands due to the stretching vibration mode could be used for the differentiation of C2-cis and C1-cis isomers of [Co(N)4(O)2] and [Co(N)2(O)4] type complexes.
The Formation of Tetrasulfur Dinitride during the Mild Pyrolysis of Tetrasulfur Tetranitride
Authors: Kudo Yoshiyuki , Hamada Shuichi 
Published: July 2006

Abstract
Tetrasulfur dinitride was formed by the mild pyrolysis of tetrasulfur tetranitride in the presence of a large amount of sulfur. The stoichiometric correlations of the pyrolytic products indicated a step-by-step degradation of the tetrasulfur tetranitride. Differential scanning calorimetry of an interrupted pyrolysis and determinations of the products gave the enthalpy of the formation of gaseous tetrasulfur dinitride as 351±3 kJ mol−1, which was reasonable judging from the bond enengies calculated by Sanderson’s method and those deduced from known bond energies. The obtained standard enthalpy of the formation of tetrasulfur tetranitride was 469±1 kJ mol−1, which agreed with the value reported by Barker et al.
The Ruthenium Catalyzed N-Alkylation of Amides with Alcohols
Authors: Watanabe Yoshihisa , Ohta Tetsuo , Tsuji Yasushi 
Published: July 2006

Abstract
Amides reacted with primary alcohols in the presence of a catalytic amount of RuCl2(PPh3)3 at 180 °C to give the corresponding N-monoalkyl amides in fairly good yields. Thus, benzamide reacted with 1-octanol to give N-octylbenzamide in 76% yield with excellent product selectivity. Little esterification of amides with alcohols occurred and selectivity to the N-alkylation was high. Most of the amides gave N-monoalkyl amides but no N,N-dialkyl amides. But formamide reacted with 1-butanol to give N,N-dibutylformamide, as well as N-butylformamide, in low yield. RuCl2(PPh3)3 was the most effective catalyst for this reaction and RuHCl(PPh3)3 also had some catalytic activity.