bluuebunny/crossref_metadata_2025 huggingface dataset:
An Alternative Display of Potentiostatic Measurements. II. Electrochemical Determination of Outer-sphere Association Constants of Several Substitution-inert Complexes with Sulfate Ions
Authors: Yamada Akifumi , Kato Yoshikiyo , Nakabayashi Yasuo , Tanaka Nobuyuki
Published: July 2006

A modified technique for the potentiostatic method has been applied to the study on the outer-sphere association of some substitution-inert complex cations with sulfate ions. The association constants were determined from the change in limiting time as function of the concentration of sulfate ions at ionic strength 0.2 and 25 °C: 29±3 for [Co(NH3)6]3+–SO42−, 23±2 for [Co(en)3]3+–SO42−, 34±3 for [Co(H2O)(NH3)5]3+–SO42−, 18±2 for [Cr(NH3)6]3+–SO42−, 21±2 for [Cr(en)3]3+–SO42−, 19±2 for [Cr(H2O)(NH3)5]3+–SO42−, 13±2 for [Cr(urea)6]3+–SO42−. The ratios of the diffusion coefficient of the univalent ion pairs to that of tervalent substitution-inert complex cations were also obtained. From these ratios, the diffusion coefficients of the univalent ion pairs were calculated; these were found to be close to those of univalent complex ions with similar structures.
The Synthesis and Luminescence Quenching of the Water-soluble Polymer-supported Tris(2,2′-bipyridine)ruthenium(II) Analogue
Authors: Kurimura Yoshimi , Shinozaki Norio , Ito Fumio , Uratani Yasuyo , Shigehara Kiyotaka , Tsuchida Eishun , Kaneko Masao , Yamada Akira
Published: July 2006

The p-aminostyrene-N-vinylpyrrolidone copolymer-supported tris(2,2′-bipyridine)ruthenium(II) analogue, [Ru(bpy)2(pbyCOOH)]2+ (bpy=2,2′-bipyridine and pbyCOOH=polymeric bipyridine ligand), has been prepared, and the luminescence behavior of the polymer complex has been investigated in an aqueous solution. The efficiency of the quenching of the excited state of the polymer complex with [Fe(CN)6]4−, [Co(phen)3]2+, and Cu2+ is compared with that of [Ru(bpy)3]2+. The quenching of the excited state of the polymer complex by Cu2+ is strongly enhanced by the effect of the polymer chains. In the polymer complex/Cu2+ system, the quenching by Cu2+ in the presence of poly(p-styrenesulfonate) is much more effective than in the absence of the polyion. The characteristics of the polymer complex in terms of the luminescence behavior are discussed.
Conformational Studies of Bis(cyclic tetrapeptide), S,S′-Bis[cyclo(Gly–l-hemiCys–Sar–l-Pro)]. A Proposed Castanet-type Structure in a Dimethyl Sulfoxide Solution
Authors: Shimizu Toshimi , Tanaka Yoshio , Tsuda Keishiro
Published: July 2006

A bis(cyclic tetrapeptide), S,S′-bis[cyclo(Gly–l-hemiCys–Sar–l-Pro)] (BCGCSP), was prepared by coupling two homodetic cyclotetrapeptide. The conformations of BCGCSP in solutions were investigated by means of NMR, Raman, and CD spectroscopy. The 1H-NMR data in dimethyl-d6 sulfoxide (Me2SO-d6) demonstrated that the two cyclic skeletons of BCGCSP take the same conformations as that of an authentic cyclic tetrapeptide, cyclo[Gly–l-Cys(Bzl(OMe))–Sar–l-Pro] (CGCSP). The 1H-NMR spectrum of CGCSP contains three sets of resonances, corresponding to three different molecular conformations. From the Raman lines of BCGCSP at 529 cm−1 and 683 cm−1 in Me2SO-d6, it is deduced that the two HCα-CβS dihedral angles are 180°(trans), while one of the SS–CβCα dihedral angles is 20–30° and the other is either near 90° or near 180°. In addition, the values of two Raman lines predict that the CβS–SCβ dihedral angle is in the range of near 90°. Such a conformation around the CβS–SCβ bond is also reasonable in the light of the presence of a CD transition (CS–SC) at λ>250 nm in water. By combining the above data, the CPK molecular model of BCGCSP was constructed. An inspection of the model reveals that this bis(cyclic tetrapeptide) is likely to adopt a “castanet-type” structure in Me2SO-d6. At the same time the individual cyclic skeleton is considered to take three different ring conformations in equilibrium.
Syntheses of Saccharin and Cyclamate Derivatives Bearing Polymerizable Vinyl Group
Authors: Kamogawa Hiroyoshi , Yamamoto Shuji , Nanasawa Masato
Published: July 2006

Vinyl monomers containing saccharin or cyclamate residues were synthesized. 6-Acrylamido-, 6-methacrylamido-, 6-(4-styrenesulfonamido)-, and 6-(vinylbenzylamino)saccharins were synthesized from 6-aminosaccharin. N-[2-(4-Styrenesulfonamido)cyclohexyl] and N-[2-(vinylbenzylamino)cyclohexyl]sulfamic acids were synthesized starting with 1,2-cyclohexanediamine via sodium N-(2-aminocyclohexyl)sulfamate. All monomers thus synthesized were found to polymerize or copolymerize with N-vinyl-2-pyrrolidone to afford vinyl polymers with pendant saccharin and cyclamate units.
Optical Resolution of 2,2′,6,6′-Tetrafluorobiphenyl-3,3′-dicarboxylic Acid
Authors: Hasaka Noriko , Okigawa Masayoshi , Kouno Isao , Kawano Nobusuke
Published: July 2006

Optically active (−)- and (+)-2,2′,6,6′-tetrafluorobiphenyl-3,3′-dicarboxylic acids were obtained through brucine salts. The half-life times for racemization of their dimethyl esters were estimated at various temperatures and the activation energy was calculated to be 25.6 kcal/mol.
Structural Studies on Herqueinone. The Configurations at C-4 of Herqueinone and at C-3 and C-4 of Dihydroherqueinone Monomethyl Ether
Authors: Yoshioka Takamitsu , Hirata Toshifumi , Aoki Tadashi , Suga Takayuki
Published: July 2006

On the basis of the 1H NMR spectroscopy and the X-ray crystallography, the configuration at C-4 of herqueinone was determined to be S and the configurations at C-3 and C-4 of dihydroherqueinone monomethyl ether were elucidated to be R and S, respectively, with relation to the previously established R-configuration at the 2′-position of herqueinone.
An FT-IR Study of Micelle Formation of Ionic Surfactants and Water Solubilization in Nonpolar Organic Solvents
Authors: Kise Hideo , Iwamoto Kazutoshi , Sen\={o} Manabu
Published: July 2006

The infrared spectra of the solutions of dodecylammonium propionate (DAP), hexadecyltrimethylammonium bromide (HTAB), and sodium bis(2-ethylhexyl) 2-sulfonatosuccinate (SBSS) in organic solvents were recorded in Fourier transform mode. Difference concentration spectra of DAP in dichloromethane exhibited the change in the stretching bands of the carboxylate ions, which was attributed to the formation of micellar aggregates. Difference hydration spectra were also obtained for water-containing DAP–CH2Cl2, HTAB–CH2Cl2, and SBSS–benzene systems, and the spectra in the region of 3000–3700 cm−1 and 1600–1650 cm−1 revealed the existence of free water dispersed in the organic phase and water bound to the micelles. The diffreence spectra also revealed the change in the bands of DAP and SBSS due to hydration of the ionic head groups. The absorption frequency of the O–H stretching bands was discussed in terms of the water-surfactant-interaction.
The Effect of Solvent on the Liquefaction of Coal as a Function of Coal Rank
Authors: Kamiya Yoshio , Yao Tadashi , Nagae Shinichi
Published: July 2006

In order to study the effect of solvent on the liquefaction of coal as a function of coal rank, the liquefaction of five kinds of coals from carbon content of 66% to 83% were carried out in the presence of various aromatic solvents. It was found that three ring aromatic hydrocarbons were more powerful solvent for the liquefaction. Hydrogen donor solvents such as tetralin and hydrophenanthrenes were most effective of all solvents tested independent of coal rank. A mixture of hydrogen donor and polar compounds such as phenol and quinoline was confirmed to be effective to bituminous coal but not so effective to brown coal. It should be stressed that hydrogen donating property of solvent is most important for low rank coals. The chemical analyses of products have shown that the properties of solvent refined coal are a little affected by the quality of solvent.
Pyridine-containing Acyclic Crown Ethers and Their Polymers as Specific Carrier of Biogenetic Amine Derivatives
Authors: Tsukube Hiroshi
Published: July 2006

A variety of crown ethers and their analogs which contain powerful hydrogen bonding sites such as pyridine and quinoline moieties were examined as new synthetic carrier. Among the examined carriers, acyclic crown ethers and their polymers having pyridine groups were found to be selective and efficient carriers for some organic ammonium cations of great biological significances. Their transport properties were largely different from those of usual crown ether compounds, and essentially dependent on the combined characteristics of polyether sequence, hydrogen bonding site, co-transported anion, and others.
Tetravalent Ruthenium Porphyrin. II. The Molecular and Crystal Structure of μ-Oxo-bis[(octaethylporphinato)ruthenium(IV) chloride] Benzene Solvate
Authors: Masuda Hideki , Taga Tooru , Osaki Kenji , Sugimoto Hiroshi , Mori Masayasu , Ogoshi Hisanobu
Published: July 2006

The crystal structure of μ-oxo-bis[(octaethylporphinato)ruthenium(IV) chloride] benzene solvate, [Ru(IV)(oep)Cl]2O–C6H6, was determined by the X-ray method. The complex crystallizes in the tetragonal space group P4/nnc, a=13.912(2) Å, c=17.821(4) Å, and Z=2. The structure was solved by the heavy-atom method and refined to R=0.084 for 958 reflections. The [Ru(IV) (oep)Cl]2O complex has the crystallographic D4-422 symmetry and contains the binuclear (Cl)N4Ru–O–RuN4(Cl) coordination group with the Ru–O(μ) distance of 1.793(2) Å, the Ru–Cl distance of 2.320(6) Å, and the Ru–N distance of 2.038(9) Å. The Ru–O–Ru bond is explicitly linear, and the two porphinato cores rotate around the Ru–O–Ru bond by 21.0° from the eclipsed form. The porphinato core is planar within 0.04 Å, and the Ru atom is displaced only by 0.07 Å out of the plane defined by the four porphinato nitrogen atoms toward the bridging O atom. These results are compared with those of the previously reported [Ru(IV)(oep)(OH)2]O–CH3OH crystal.
Stabilization Energy and Spin Distribution in Pyrenophane Cation Radicals
Authors: Terahara Atsushi , Ohya-Nishiguchi Hiroaki , Hirota Noboru , Sakata Yoshiteru , Misumi Soichi , Ishizu Kazuhiko
Published: July 2006

The cation radicals of three [2.2]pyrenophanes in which two pyrene moieties are twisted each other by 0°, 35°, and 60° were investigated by ESR, ENDOR, and cyclic voltammetry. Considerable variations of the spin density distribution and the stabilization energy with the twisting angle have been observed. The obtained results are discussed in terms of modified Hückel-McLachlan type calculation.
Studies on the Concentrated Steffen Fluid of Beet Sugar Industry. I. On the Salt Separated from Concentrated Steffen Fluid Using Methanol and Sulfuric Acid
Authors: Ito Masaaki , Abe Kazuo , Sasaki Teruji , Wakabayashi Norimitsu , Misono Kenzo
Published: July 2006

The chemical desalting technique was applied to the concentrated Steffen fluid using concd sulfuric acid and methanol. The chemical components of the isolated salt were studied by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and fluorescence analyses. The main constituent of the salt was determined to be K3Na(SO4)2 and then synthesized.
Solvent Intensification Effects on the S1(nπ*)←S0 Absorption Spectra of Benzaldehyde in Fluid Solutions
Authors: Nakashima Kenichi , Koyanagi Motohiko
Published: July 2006

The near ultraviolet absorption spectra of benzaldehyde have been studied in various fluid solutions at room temperature. The intensity enhancements observed are explainable in terms of perturbation of dispersion forces between solute and solvent molecules.
Photolyses of [2-Substituted 2-(alkoxycarbonyl)propyl]cobaloximes
Authors: Tada Masaru , Akinaga Shiro , Okabe Masami
Published: July 2006

Photolysis of (2-methoxycarbonyl-2-phenylpropyl)cobaloxime (1) gives two phenyl-migrated products, methyl 2-methylene-3-phenylpropanoate and methyl trans-2-methyl-3-phenylpropenoate, and a hydrogen-abstracted product, methyl 2-methyl-2-phenylpropanoate. The alkoxycarbonyl groups do not migrate in the photolysis of either 1 or [2,2-bis(ethoxycarbonyl)propyl]cobaloxime.
Protonation of syn-Bicyclo[4.2.1]nona-2,4,7-trien-9-ol with Fluorosulfuric Acid. Direct Evidence for Protonation Sites
Authors: Tomoda Shuji
Published: July 2006

Treatment of syn-9-hydroxybicyclo[4.2.1]nona-2,4,7-triene (1) with fluorosulfonic acid in sulfur dioxidedichloromethane-d2 cleanly provided protonated dimeric ether and the 7-hydroxytricyclo[4.2.1.02,8]nona-3-en-5-yl cation. Direct NMR observation as well as quenching experiment of these cations unequivocally established protonation at C-2 (or C-5) and C-7 (or C-8) of 1.
Electrolytic Decarboxylation. 6. A Convenient Synthesis of 3-(cis-3-Hexenyl)-2-cyclopentenone, a Precursor of cis-Jasmone Synthesis
Authors: Torii Sigeru , Tanaka Hideo , Inokuchi Tsutomu , Tomozane Kazuo
Published: July 2006

A regioselective electro-acetoxylation of 1-(cis-3-hexenyl)-2-cyclopentene-1-carboxylic acid in a Et3N–AcOH–AcOEt–t-BuOH–(Pt electrodes) system afforded 3-acetoxy-1-(cis-3-hexenyl)-1-cyclopentene (7a) (98%). Alkaline hydrolysis of 7a followed by the oxidation with chromium trioxide gave the desired 3-(cis-3-hexenyl)-2-cyclopenone smoothly.
Catalysis by Heteropoly Compounds. III. The Structure and Properties of 12-Heteropolyacids of Molybdenum and Tungsten (H3PMo12−xWxO40) and Their Salts Pertinent to Heterogeneous Catalysis
Authors: Misono Makoto , Mizuno Noritaka , Katamura Koichi , Kasai Atsushi , Konishi Yasuo , Sakata Kanji , Okuhara Toshio , Yoneda Yukio
Published: July 2006

The fundamental properties of 12-heteropolyacids of Mo and W, such as the structure, the surface area, the acidity, and the reduction-oxidation mechanism, have been studied in their solid state in relation to heterogeneous catalysis. The primary structure (heteropolyanion) was rather stable, but the secondary structure was very variable according to the interaction with various molecules, like water, alcohols, ketones, and pyridine. This structural characteristic is important for the understanding of the catalysis of these compounds; it may be called the “pseudo-liquid phase.” The heteropolyacids were all strong protonic acids, as revealed by the interaction with pyridine. The redox cycle was reversible within a limited extent of reduction. The redox mechanism is also discussed in this paper.
The Structure of the Cyclodextrin Complex. XI. Crystal Structure of Hexakis(2,3,6-tri-O-methyl)-α-cyclodextrin–p-Iodoaniline Monohydrate
Authors: Harata Kazuaki , Uekama Kaneto , Otagiri Masaki , Hirayama Fumitoshi
Published: July 2006

The crystal structure of hexakis(2,3,6-tri-O-methyl)-α-cyclodextrin–p-iodoaniline complex, C54H96O30·C6H6NI·H2O, was determined by the X-ray method. The crystal is monoclinic with the space group P21, Z=2, a=11.440(4), b=23.674(6), c=13.531(3) Å, and β=91.90(2)°. The structure was solved by the heavy atom method combined with the rigid-body least-squares technique and refined by the block-diagonal least-squares method to the final R-value of 0.11 for 2186 reflections (sinθ⁄λ<0.49). Hexakis(2,3,6-tri-O-methyl)-α-cyclodextrin is in the shape of a truncated elliptical cone; these cones are stacked along the a axis to form a channel-type structure. The guest p-iodoaniline and water molecules are located in the channel. The iodophenyl group is inserted rather loosely from the base side of the truncated cone. The iodine atom is located at the center of the cavity, while the amino group outside the host cavity forms a hydrogen bond with the water molecule. The water molecule is also hydrogen bonded to the adjacent host molecule along the channel. The crystal is built up of columns of the host molecules, which are closely packed in the van der Waals contact.
Kinetics and Mechanism of 1,4-Cycloaddition between Tetracyanoethylene and Styrenes. III. Effects of Solvent Polarity and Temperature
Authors: Uosaki Yasuhiro , Nakahara Masaru , Osugi Jiro
Published: July 2006

Experimental evaluation was made of rate constants for foward and backward steps of 1,4-cycloaddition between TCNE and α-methylstyrene and of constants for their complex formations in 1,2-dichloroethane, dichloromethane, chloroform, and carbon tetrachloride at a few temperatures around 25 °C. Kirkwood’s dipole model for solvation is applied to analyzing kinetic data obtained. The dipole moment of the transition state is estimated to be 8.5±0.5 Debye, which is larger than either that of the complex (assumed as 1 Debye) or that of the cycloadduct (6±1 Debye). Major cause for the high dipole moment of the transition state is breakdown of the high molecular symmetry of TCNE and minor one is a certain contribution of a zwitterionic structure. The activation entropy for the cycloreversion is negative and in the range of −21 to −48 J K−1 mol−1, corresponding to the high polarity of the transition state.
Plasma Treatment of Packing Materials for Gas Chromatography. Diatomaceous Earth Coated with Squalane
Authors: Yamamoto Yukio , Oka Seiji , Hayashi Koichiro
Published: July 2006

Commercially obtained column packings for gas chromatography, diatomaceous earth coated with 5% squalane, were treated with argon plasma by using a radiofrequency generator. It has been shown that the plasma treatment improves the chromatographic properties, in particular, reduces the tailing of aromatic hydrocarbon peaks. The effect of the plasma treatment has been attributed to the reduction of the support adsorptivity by the formation of inert coating on the support surface.
197Au-Mössbauer Spectroscopic Studies of Gold Compounds
Authors: Katada Motomi , Uchida Yoshio , Sato Kumiko , Sano Hirotoshi , Sakai Hiroshi , Maeda Yutaka
Published: July 2006

197Au Mössbauer effect measurements of mixed-valence compounds and chelates of Au(III) with ligands of 1,10-phenanthroline, 8-quinolinol, and their derivatives have been carried out. The Mössbauer data of Cs2Au2Cl6, Cs2AgAuCl6, and [Au(phen)Cl2]Cl show the existence of an interaction between metal atoms through Cl atoms. Although the metal-metal interaction in [Au(Hdmg)2][AuCl2] has been postulated by X-ray study, no such interaction was observed. Two kinds of 8-quinolinol Au(III) complexes which have cis-trans isomers are assigned to the compounds of the [Au(oxine)2][AuCl4] and [Au(oxine)Cl2] types.
Thermochemical Studies on the Lanthanoid Complexes of N,N,N′,N′-Tetramethylurea
Authors: Sone Kozo , Nagase Kenzo , Kuya Miuaco K , Giesbrecht Ernesto
Published: July 2006

The techniques of thermogravimetry (TG) and differential thermal analysis (DTA) were applied to the study of the thermal decomposition of the lanthanoid (Ln) complexes of N,N,N′,N′-tetramethylurea (TMU), Ln(TMU)6X3 (X=ClO4, PF6, or BPh4). In general, the ease of decomposition increases in the order of BPh4<ClO4<PF6; in the latter two cases, the release (and, in the case of ClO4, partial oxidation) of the coordinated TMU molecules takes place together with the decomposition of the anions, leading finally to the formation of LnCl3 or LnF3, respectively. The data were also discussed on the basis of the effects of the lanthanoid contraction.
An X-Ray Diffraction Study on the Structures of Bis- and Tris(ethylenediamine)nickel(II) Complexes in Solution
Authors: Fujita Tadao , Ohtaki Hitoshi
Published: July 2006

The structures of nickel(II) complexes with ethylenediamine(en) in solution have been determined by means of X-ray diffraction. The measurements were performed at 25 °C for aqueous ethylenediamine solutions of nickel nitrate, the mole ratios (en/Ni) in the solutions being 3.964, 3.672, 2.071, and 1.892. In the two solutions of the higher en/Ni mole ratio, the tris(ethylenediamine)nickel(II) complex was predominant, whereas in the other solutions the bis(ethylenediamine)nickel(II) complex was contained as the main species. From the analysis of the X-ray scattering data of the solutions, it was shown that in the bis-complex four nitrogen atoms within ethylenediamine and two oxygen atoms within water molecules were octahedrally coordinated to the central nickel(II) atom, the oxygen atoms being assumed to be axially bonded. The Ni–N bond length within the bis-complex was 2.10 Å, which was almost the same as the length of the Ni–O bonds. The nonbonding Ni···C distance was 2.82(2) Å. In the tris-complex the nickel ion was coordinated with six nitrogen atoms and Ni–N and Ni···C distances were determined to be 2.202(4) Å and 2.88(1) Å, respectively. These parameter values obtained in the experiment were compared with the crystallographic data reported.
Preparation of Surfactant-free Polystyrene Latices with High Surface Charge and Electrical Double Layer on Their Surfaces
Authors: Furusawa Kunio
Published: July 2006

Polystyrene latices with a wide range of surface charges were prepared in the absolute absence of conventional emulsifiers by controlling the concentration of potassium peroxodisulfate as an initiator and allowing the polymerization to proceed at a relatively high pH to suppress the Kolthoff reaction; KHCO3 or K2HPO4 buffer was used to keep the polymerizing system near neutral pH. Conductometric titrations with different bases (NaOH and Ba(OH)2) on latices show that the Stern layer charge increases with an increase in the surface charge of latices (σ0) and at about the same rate as σ0 does, leading to a virtually constant diffuse layer charge.
Carbene in Rigid Matrix. XI. Temperature and Matrix Effect on Phenylcarbene Processes in Ether and Amine
Authors: Tomioka Hideo , Suzuki Shinji , Izawa Yasuji
Published: July 2006

Product distributions from reactions of phenylcarbene with diethyl or diisopropyl ether or diethylamine were found to be highly dependent on reaction temperature. As temperature decreases, the C–O displacement reaction and N–H insertion are decreased. Concomitantly, primary C–H insertion products markedly increase especially at lower matrix temperatures.
The Cyclic Voltammetry and Cathodic Reduction of Steroidal Homoallylic Nitro Esters. Dimerization vs. Cyclopropane Formation
Authors: Sato Takeo , Komeichi Yoshihisa , Kobayashi Shoichi , Omura Aira
Published: July 2006

The cathodic reduction of homoallylic nitro esters was carried out in DMF–TBAP using platinum electrodes. The reaction was found to be highly dependent on the ester-leaving group: Whereas 6-nitrocholest-5-en-3β-yl acetate (3a) gave a 3,3′-dimer 4, 3β-tosylate 3d gave a cyclosteroid, 6β-nitro-3α,5-cyclo-5α-cholestane (7). 3β-Trifluoroacetate showed intermediate behavior and gave both 4 and 7. Similarly, 6-nitrocholest-5-ene-3β,19-diol 3-acetate 19-tosylate gave 5β,19-cyclosteroid. The cyclic voltammetry was carried out for these and related compounds. A reversible cyclic voltammogram was recorded for 3a, but 3d showed no anodic peak on potential reversal. A possible electron-transfer and the following chemical-reaction mechanism was discussed.
Carbon-Carbon Bond Formation by the Use of Chloroiodomethane as a C1 Unit. III. A Convenient Synthesis of the Mannich Base from Enol Silyl Ether by a Combination of Chloroiodomethane and N,N,N′,N′-Tetramethylmethanediamine
Authors: Miyano Sotaro , Hokari Hiroshi , Hashimoto Harukichi
Published: July 2006

The Mannich dimethylaminomethylation of carbonyl compounds is conveniently carried out via enol trimethylsilyl ethers by a combination of chloroiodomethane (CH2ClI) and N,N,N′,N′-tetramethylmethanediamine (TMMD) in DMSO as the solvent at ambient temperature. The mechanism of the transformation is discussed on the basis of product analysis and 1H NMR spectral studies. The reagent system CH2ClI/TMMD also provides a convenient route to the Eschenmoser’s salt (Me2\overset+N=CH2,\overset−I).
The Interaction of the Tris(2,2′-bipyridine)ruthenium(II) Ion with Poly(p-styrenesulfonate)
Authors: Kurimura Yoshimi , Yokota Hiroshi , Shigehara Kiyotaka , Tsuchida Eishun
Published: July 2006

The interactions of tris(2,2′-bipyridine)ruthenium(II)([Ru(bpy)3]2+) with some polyanions have been studied by means of cation-exchange resins and the luminescence of [Ru(bpy)3]2+. In an aqueous solution of [Ru(bpy)3]2+ in the presence of sodium poly(p-styrenesulfonate)(PSS), the adsorbability of [Ru(bpy)3]2+ on the cation-exchange resins is strongly suppressed by the binding of [Ru(bpy)3]2+ to the polyanion. The relative luminescence intensity of [Ru(bpy)3]2+ in an aqueous solution is enhanced by the addition of PSS. With the addition of sodium chloride to an [Ru(bpy)3]2+/PSS solution, the interaction is impeded by the shielding of the electrostatic potential in the polymer domains by the counter ions. A cooperative interaction between PSS and [Ru(bpy)3]2+ is postulated with a view to accounting for the results. A chemical application of the interaction is demonstrated.
Products and Kinetic Substituent Effects in the Reactions of Diaryldiazomethanes with 2,5-Dichloro-p-benzoquinone
Authors: Oshima Takumi , Nagai Toshikazu
Published: July 2006

Substituted diphenyldiazomethanes[(x-C6H4)2CN2; x=p-OCH3, p-CH3, H, p-Cl] were found to react with 2,5-dichloro-p-benzoquinone at its conjugated C=C and C=O bonds to give bicyclic diones and poly(2,5-dichlorohydroquinone benzhydryl ether)s respectively, obeying the second-order kinetic law. The product ratios of the polyethers to the bicyclic diones increased from 1.1 to 8.1 with the electron-donating ability of the substituents. The individual rate constants were well correlated with the Hammett equation: logk3=−2.15–1.55 σ (r=0.996) and logk4=−2.03–1.85 (σ0+0.515Δ\barσR+) (r=1.00) for the bicyclic diones and polyethers processes respectively. The presence of methanol as a trapping agent stopped the polymerization completely and afforded the methanolysis product, though no essential change was found in the formation of the bicyclic dione.
Kinetic Solvent Effects in the Decomposition of Diphenyldiazomethane with Chloranil and 2,5-Dichloro-p-benzoquinone
Authors: Oshima Takumi , Nagai Toshikazu
Published: July 2006

A kinetic study was made of the reactions of diphenyldiazomethane (DDM) with chloranil and 2,5-dichloro-p-benzoquinone (DCQ) at 30 °C in 20 and 22 aprotic solvents respectively (19 solvents are common). The chloranil reaction gave poly(tetrachlorohydroquinone benzhydryl ether) alone, obeying the second-order kinetic law. On the other hand, the DCQ reaction afforded bicyclic dione and poly(2,5-dichlorohydroquinone benzhydryl ether), also obeying the second-order kinetic law. All these rate constants generally increased with the solvent polarity and decreased with the solvent basicity. The kinetic solvent effects can be interpreted in terms of the effects of the polarity and the basicity of the solvents respectively to the transition and to the initial states. Thus, the multiple liner correlations of the logarithmic rate constants with a suitable function of the polarity and the basicity of the solvents are fairly successful. It was found that the basicity is more pronounced in the chloranil reaction than in the DCQ reaction, whereas the reverse can be said for the solvent polarity. These results were compared to those of the reactions of DDM with 2,3-dichloro-5,6-dicyanobenzoquinone and tetracyanoethylene.
Computation of Amino Acid Sequences of Polypeptides from Masses of Their Constituent Peptide Fragments and Amino Acid Residues Released in Edman-degradation
Authors: Kitagishi Toyoko , Hong Yeong-Man , Takao Toshifumi , Aimoto Saburo , Shimonishi Yasutsugu
Published: July 2006

A computer program (“PROSEQ2”) was designed for determining the amino acid sequence of polypeptides from molecular weights and N-terminal amino acid residues of two or more sets of peptide mixtures obtained from polypeptides by two or more specific cleavage methods, together with 3-phenyl-2-thiohydantoin derivatives of amino acids released from two or more sets of peptide mixtures by Edman-degradation. Computation of sequences of several polypeptides using this program is described.
The Crystal and Molecular Structure of Pikromycin
Authors: Furusaki Akio , Matsumoto Takeshi , Furuhata Kimio , Ogura Haruo
Published: July 2006

The detailed molecular geometry of pikromycin (C28H47NO8) has been examined by means of X-ray crystal analysis. The crystals are orthorhombic, with four molecules in a unit cell with dimensions of a=11.295, b=25.734, and c=10.509 Å; the space group is P212121. 2259 unique intensity data were collected on a four-circle diffractometer with graphite-monochromated Cu Kα radiation. The structure was solved by the Monte Carlo direct method, using the 30 strongest reflections as the starting set; the 215th random phase set led to the correct solution. The R value reached 0.056 by block-diagonal least-squares refinements. The conformation of the fourteen-membered macrolide ring is considerably different from that of (p-bromobenzoyl) pikromycin in the solid state; e.g., the C=C and C=O conjugated double bonds are cisoid in pikromycin, while they are transoid in the derivative. The molecules are held together through two kinds of intermolecular hydrogen bonds, forming a three-dimensional hydrogen-bonded structure.
Polarographic Behavior of 4-Morpholine Carbodithioate and Its Use in the Amperometric Determination of Metal Ions
Authors: Rao A L J , Brar Bikram S , Puri B K
Published: July 2006

Polarographic behavior of 4-morpholine carbodithioate has been studied in various base electrolytes. It gives a well defined, diffusion controlled, reversible with one electron change, anodic wave above pH 9 extending over a fairly wide span of potential, +0.2 V to −0.3 V vs. SCE. The relation between diffusion current and concentration is linear up to 2.7 mM (1 M=1 mol dm−3) of the reagent. The reagent has been successfully applied for the amperometric determination of Bi3+, Cu2+, Ni2+, Te4+, and Zn2+ individually as well as in mixtures like Cu–Zn and Cu–Ni. Conditions have also been developed for the determination of copper, nickel, and zinc in various alloys. The error does not exceed more than ±0.85% in any case. The method is simple, less time consuming and easily adoptable for the micro determination of these metal ions.
Linear Solvation Energy Relationships. 18. Solvent Effects on the Electronic Absorption Spectrum of p-Nitrophenoxide Ion
Authors: Abboud José-Luis M , Taft Robert W , Kamlet Mortimer J
Published: July 2006

A quantitative analysis of the effects of hydroxylic and aprotic solvents on the electronic absorption spectrum of 4-nitrophenoxide anion is described. By means of linear solvation energy relationships, the contributions of solvent dipolarity, polarizability, and hydrogen bonding are assessed. A significant conclusion is that ion-pairing strongly influences the 4-nitrophenoxide ion in aprotic solvents, but not in hydroxylic solvents. In the latter, specific solvation of both the nitro group and the phenoxide ion center are important.
Dimerization Kinetics of Fluoresceine in Aqueous Solution
Authors: Inaoka Wataru , Harada Shoji , Fujii Susumu , Yasunaga Tatsuya
Published: July 2006

Kinetic studies of the dimerization reaction of fluorescein (doubly charged anion) in aqueous solution were performed by the ultrasonic absorption method. The data obtained could not be interpreted by the rate equation derived with the usual viscosity effect assumed for the diffusion process. Rather, an experimental equation was found, which adequately fits the data. Here, the viscosity contribution is kf=kf0⁄ηr, kb=kb0, and K=K0⁄ηr.
X-Ray Structure of (1RS, 5RS, 7SR)-1-Acetoxy-7-cyano-5-methylbicyclo[3.2.0]heptan-2-one, a Photocycloadduct of 2-Acetoxy-3-methyl-2-cyclopenten-1-one and Acrylonitrile
Authors: Furusaki Akio , Abe Katsumi , Matsumoto Takeshi
Published: July 2006

The main product of the photocycloaddition between 2-acetoxy-3-methyl-2-cyclopenten-1-one and acrylonitrile has been found to be (1RS, 5RS, 7SR)-1-acetoxy-7-cyano-5-methylbicyclo[3.2.0]heptan-2-one by means of X-ray crystal structure analysis.
The Thermal Decomposition of Crystalline Antimonic(V) Acid
Authors: Abe Mitsuo , Sudoh Kazufuyu
Published: July 2006

The thermal decomposition of crystalline antimonic(V) acid (C-SbA) was studied by means of DTA, DSC, and DTG. The amount of water evolved from the heated C-SbA was determined by the Karl Fischer method. The material heated in the range of 600–1000 °C is Sb6O13, neither Sb3O6(OH) nor H2Sb12O26. The thermal decomposition of C-SbA consists of four dehydration and two reduction steps up to 1000 °C.
Circular Dichroism Spectra of cis,cis-[Co(OO)(N)2(py)2]+-Type Complexes
Authors: Fujinami Shuhei , Tsuji Kenshi , Musa Ritsuko , Shibata Muraji
Published: July 2006

Four new complexes, cis,cis-[Co(OO)(NH2C2H5)2(py)2]+(OO=CO32−, ox2−, or mal2−) and cis,cis-[Co(ox)(NH3)2(py)2]+, have been prepared and optically resolved. The CD patterns regularly change in the order of carbonato, oxalato, and malonato complexes, the aspect in the change being opposite to that of related cis,cis-[Co(NO2)2(OO)(NH3)2]−-type complexes.
A New Phase of Compound CaMnO2+δ
Authors: Takahashi Koichiro , Yamamura Hiroshi , Muramatsu Kunitaka , Shirasaki Shin-ichi , Suehiro Kensuke
Published: July 2006

A new phase of CaMnO2+δ was synthesized by a wet process, followed by calcining. The structure was determined to be orthorhombic, with these lattice constants: a=5.96, b=14.38, and c=5.72 Å. Phase transformations among CaMnO2+δ compounds were studied in various atmospheres, such as N2, CO2, and air.
Spectrophotometric Determination of Sodium 4-Dodecylbenzenesulfonate with 1-(N-Methylpyridinium-4-yl-azo)-4-(4-diethylaminophenylazo)naphthalene Iodide
Authors: Higuchi Keiro , Shimoishi Yasuaki , Miyata Haruo , Tôei Kyoji
Published: July 2006

A new reagent, 1-(N-methylpyridinium-4-yl-azo)-4-(4-diethylaminophenylazo)naphthalene iodide, can react with sodium 4-dodecylbenzenesulfonate to show a color change in an aqueous phase in the presence of iodide ion. The calibration graph is straight line up to 1.2×10−5 M (1 M=1 mol dm−3); ε=3.25×104 1 mol−1 cm−1 at 580 nm.
Reaction of Nitrostyrenes and 1-Nitrohexane with Sodium Polysulfides and Sodium Hydroxide
Authors: Ogata Yoshiro , Nakagawa Yoshiaki , Inaishi Morio
Published: July 2006

The reaction of β-nitrostyrene with NaOH in refluxing EtOH–H2O (1 : 2) gives benzaldehyde, benzyl alcohol, benzoic acid, phenylacetic acid, β-phenylethyl alcohol, and polymeric materials. On the other hand, the reaction of β-nitrostyrene with Na2S4–NaOH in the same solvent gave acetophenone besides the same products obtained with NaOH. Acetophenone was likewise detected in the Na2S–NaOH and Na2S2–NaOH reactions. 4-Nitrostyrene was also allowed to react with Na2S4–NaOH in EtOH–H2O (4 : 1) to give a small amount of 4-aminoacetophenone. The formation of acetophenones suggests the occurrence of the Michael addition of polysulfide ion and supports our mechanism proposed previously for the reaction of p-nitrotoluene with Na2S4. The reaction of 1-nitrohexane with Na2S4–NaOH, in which the Michael addition is not conceivable, gives the same products as the reaction with NaOH.
The Direct Synthesis of Methyl 2,4-Di-O-benzyl-α-d-xylopyranoside by the Regiospecific Benzylation of Methyl α-d-Xylopyranoside
Authors: Morishima Naohiko , Koto Shinkiti , Kusuhara Chiharu , Zen Shonosuke
Published: July 2006

The regiospecific benzylation of methyl α-d-xylopyranoside with benzyl chloride and sodium hydride produces methyl 2,4-di-O-benzyl-α-d-xylopyranoside in a 70% yield, together with the by-products, methyl 2,3- and 3,4-di-O-benzyl-α-d-xylopyranosides. The structure of the 2,4-di-O-benzyl derivative was confirmed through the alternative synthesis of the 2,3- and 3,4-di-O-benzyl derivatives via the O-isopropylidene and O-cyclohexylidene derivatives of methyl α-d-xylopyranoside.
Synthesis of N2-Protected l-2,3-Diaminopropanoic Acids
Authors: Noguchi Noriyoshi , Kuroda Tsuyoshi , Hatanaka Minoru , Ishimaru Toshiyasu
Published: July 2006

The title compounds have been synthesized from N-protected l-aspartic acid via Curtius rearrangement.
ESR Spectra of Anion Radicals of 8,8-Dicyanoheptafulvene and Its 4,5-Benzo Derivative
Authors: Ikegami Yusaku , Muramatsu Takashi , Asao Toyonobu
Published: July 2006

The hyperfine splitting constants for the 8,8-dicyanoheptafulvene anion radical generated electrolytically at low temperature indicate that the unpaired spin belongs to an a2 orbital of the group C2v. Its 4,5-benzo derivative gives a stable anion radical by reduction with alkali metals. The odd electron belongs to a b2 orbital.
Electrohydrodynamic Dissipative Structure in Unipolar and Bipolar Injection Cases
Authors: Aikawa Yoshihiro , Shimoda Haruhisa , Kobayashi Kenkichiro , Takahashi Akira , Takeda Shuzaburo , Sakata Toshibumi , Sukigara Mitsunori
Published: July 2006

An electrohydrodynamic dissipative structure appearing in a suspension system of TiO2 particles in organic solvents is analyzed from a viewpoint of thermodynamics. This analysis gives rather a general explanation for electrohydrodynamic instability caused by unipolar injection and for that caused by bipolar injection. Dimensionless parameters which are the criteria of the hydrodynamic instability are given as R=εV⁄ημ and R=ε2V2⁄nqμηc2 respectively for the former and latter cases. The lattice constant of the hexagonal dissipative structure is derived to be proportional to the thickness of the liquid layer.
Electrolytic Reduction of Carbon Dioxide at Mercury Electrode in Aqueous Solution
Authors: Hori Yoshio , Suzuki Shin
Published: July 2006

Cathodic reduction of carbon dioxide at a mercury pool electrode was investigated in aqueous solutions of NaHCO3, NaH2PO4–Na2HPO4, NaCl, NaClO4, Na2SO4, LiHCO3, and KHCO3 as well as their combinations. The reaction product was confirmed to be HCOO− by a qualitative spot test. HCOO− was quantitatively analyzed by a permanganate titration. The partial current densities of HCOO− formation (ic) and H2 evolution (iH) were calculated. In the present paper, relationships between electrode behavior and solution properties, some of which have been qualitatively described in previous papers, are quantitatively clarified as follows. The electrode potential Ec for constant ic (0.5 mA/cm2) remains constant irrespective of pH and anions in the pH region of 2.4 to 7.8, whereas the potential EH for constant iH (0.5 mA/cm2) varies linearly with a slope of 125 mV/pH. The present experimental results verify Eyring et al.’s presumption that in a relatively high overvoltage region (region 2) the cathodic reduction of CO2 at Hg proceeds with the charge transfer to CO2 as the rate determining step. CO2 reduction and H2 evolution are concluded to proceed independently at the Hg electrode. The dependence of Ec on electrolyte concentration is interpreted in terms of the diffuse double layer theory. The effect of cation species on Ec also is discussed.
New Application of PAS for In Situ Observation of Semiconductor Electrode Surface
Authors: Masuda Hideki , Fujishima Akira , Honda Kenichi
Published: July 2006

The photoacoustic spectroscopic technique was used to study in situ cathodic decomposition of CdS and ZnO semiconductor electrodes and electrochemical deposition of metal ions (Cd2+ and Zn2+) on the semiconductor electrodes.
1H and 19F Nuclear Magnetic Relaxation Studies of Molecular Motion in Solid Fluoroform
Authors: Eguchi Taro , Kishita Michihiko , Chihara Hideaki , Soda Gen
Published: July 2006

Spin-lattice relaxation times of proton and fluorine nuclei in solid CHF3 were measured by the pulsed magnetic resonance technique between 7 and 116K. In 1H resonance, non-exponential recovery of magnetization was clearly observed. T1 data as well as magnetization recoveries were interpreted in terms of intramolecular magnetic dipole interactions between like spins and also between unlike spins, which are modulated by the isotropic reorientation of a whole molecule. A calculation of the temperature dependence of T1 was made by using an activation energy of 17kJ mol−1 and a pre-exponential factor of 1.0×10−16 s for the motion, yielding results in agreement with the present experimental results.
The Adsorption of Amino Acids from Water on Activated Carbons
Authors: Abe Ikuo , Hayashi Katsumi , Kitagawa Mutsuo
Published: July 2006

Freundlich’s adsorption constants of 17 amino acids from aqueous solutions onto an activated carbon have been determined and correlated with various physical constants. A good linear relationship is obtained between the adsorption constants and such physical constants as the molecular refraction and the parachor. The adsorption isotherms of amino acids can be predicted from the molecular refraction or the parachor alone.
UV Absorption Studies of the Pyrolysis of Isobutane in Shock Waves
Authors: Koike Tohru , Morinaga Kihei
Published: July 2006

The UV absorption measurements at 216 nm were carried out for two shock-heated mixtures, 1.5 and 2.0% i-C4H10 diluted in Ar, in the temperature range of 1300–1800 K, and at an atmospheric pressure of about half. From the initial absorption rise attributed to the CH3 growth, the rate constant of the initiation reaction, i-C4H10=CH3+i-C3H7, was evaluated as k=1012.8±0.5exp[−(60.8±4.6) kcal/RT]/s−1. A comparison between the k value so derived and the formerly reported values was made. A computer modeling using a 39-reaction mechanism could reproduce the absorption at the early stage of the reaction at temperatures lower than 1550 K, whereas the modeled absorption was smaller than the measured at much high temperatures. The absorption by C3H5 (allyl radical) must be taken into account in order to lessen this difference.
X-Ray Photoelectron Spectroscopic Study of Highly Conductive Bromine-doped Polyacetylene
Authors: Ikemoto Isao , Cao Yong , Yamada Masamichi , Kuroda Haruo , Harada Issei , Shirakawa Hideki , Ikeda Sakuji
Published: July 2006

The bromine-doped polyacetylenes were studied by X-ray photoelectron spectroscopy. The IR, Raman, and mass spectra were also measured. We find that below the doping content at which the electrical conductivity shows the maximum, bromine content is higher in the surface region than in the bulk. The C ls peak of X-ray photoelectron spectrum is composed of at least two components with the splitting of about 1.7 eV. The relative intensities of two components change with bromine content. The higher-binding-energy component of C ls peak is attributed to positively charged carbon atoms in the metallic domains where dopant is highly concentrated, and the lower-binding-energy component to carbon atoms in the undoped low-conductive domains. The amount of charge transfer in the metallic domain is estimated to be about 0.3|e| per carbon atom. A possible reaction mechanism of bromine with polyacetylene is discussed.
Reduction of Chromium(VI) by Iron(II) Hydroxide in Alkaline Solution
Authors: Aoki Toyoaki , Munemori Makoto
Published: July 2006

Iron(II) hydroxide stoichiometrically reduces CrO42− to chromium(III) in alkaline solutions of pH 8 or above. This reduction was finished in less than one minute even at 5 °C. Although chromium(III) dissolves as CrO2− above pH 9.5, it did not dissolve in the presence of iron(III) hydroxide which had resulted from the oxidation of iron(II) hydroxide.
Determination of Trace Amounts of Iron, Nickel, and Tin in Zircaloys by X-Ray Fluorescence Spectrometry after Coprecipitation with Hexamethyleneammonium Hexamethylenedithiocarbamate
Authors: Yamamoto Yoshikazu , Sugita Michiyuki , Ueda Kazumasa
Published: July 2006

A rapid and precise X-ray fluorescence spectrometry is proposed for the determination of the trace amounts of iron, nickel, and tin in zircaloys. A zircaloy sample was dissolved in a mixture of tetrafluoroboric acid and hydrochloric acid, diluted to a definite volume with water. After the addition of 3 cm3 of 1% (R,R)-tartaric acid solution as an auxiliary chelating agent and 50 μg of cobalt as an internal standard to an aliquot (less than 200 μg of tin) of the solution, the pH was adjusted to 2 with ammonia solution and 3 cm3 of 1% hexamethyleneammonium hexamethylenedithiocarbamate (HMA–HMDC) was added. The resulting HMA–HMDC complexes were collected on a membrane filter and dried. The contents of iron, nickel, and tin in zircaloys were calculated by the calibration curves with the ratios of Kα intensities for each element to that for cobalt. The coefficients of variation (5 results for each metal) were 2.16, 0.63, and 1.52% for 10, 10, and 200 μg of iron, nickel, and tin, respectively. The analytical results of iron, nickel, and tin in zircaloy samples by the proposed method agreed with the certified values.
The Phases Formed by the Dehydration of Disodium Zirconium(IV) Bis(orthophosphate) Trihydrate and Their Ion-exchange Behavior
Authors: Inoue Yasushi , Yamada Yoshimune
Published: July 2006

The phase transformation of Na2Zr(PO4)2·3H2O which had been obtained from zirconium(IV) bis(hydrogenphosphate) monohydrate(α-zirconium phosphate), prepared by the direct precipitation method, was studied by means of gravimetry, X-ray analysis, and acid-base titration. When the material was heated for 2 d, it was transformed to a monohydrate at 80 °C and then successively to three anhydrous phases, depending on the temperature. The monohydrate was also formed by letting the trihydrate stand over P2O5 at room temperature for longer than two weeks. The processes were confirmed to be irreversible by an examination of the rehydration behavior, from which the conditions of the storage of five modifications of disodium zirconium(IV) bis(orthophosphate) were established. It is of special interest that the second anhydrous phase reverted to the first one when it was allowed to stand at room temperature in air or in a desiccator. The rate of the reversion decreased with the temperature of heat-treatment and with a decrease in the relative humidity of the surroundings. The difference between the present results and Clearfield’s was clarified and attributed mainly to the difference in the crystallinity of the starting α-zirconium phosphate.
A Ruthenium(IV)-Ruthenium(III) Dimer, Product of the Reaction of Aqua(ethylenediaminetetraacetato)ruthenium(III) with Chlorate Ions
Authors: Ikeda Masato , Shimizu Kunio , Satô Gen P
Published: July 2006

An oxo-bridged, mixed-valence complex of ruthenium(IV,III), [(edta)RuIVORuIII(edta)3−, has been obtained from the oxidation of [RuIII(edta)(H2O)]− by chlorate ions. The formulation of the complex as a μ-oxo dimer of ruthenium(IV,III) is based on the results of a variety of experiments, including elemental analyses, magnetism, by spectrophotometry, and by electrochemical studies. These studies in acetate buffer solution show that the dimeric ion can be reduced at mercury electrode to [(edta)RuIIIORuIII(edta)]4− and then is monomerized to the original [Ru(edta)(H2O)]− in a fast reaction.
Photoreaction of Tris(ethylenediamine)cobalt(III) Ion with Bis(2-hydroxyethyl)dithiocarbamate Ion
Authors: Nakashima Michio , Kida Sigeo
Published: July 2006

Complete ligand replacement of tris(ethylenediamine)cobalt(III)([Co(en)3]3+) by bis(2-hydroxyethyl)dithiocarbamate ion(htc−) forming [Co(htc)3] is induced by visible light in aqueous solution. The quantum yield of the reaction depends on the wavelength of the light and on the concentrations of the complex and the ligand. The distinct feature of this photo-induced substitution is that the quantum yield is higher than unity for the solution containing 0.02 mol dm−3 [Co(en)3]3+ and 0.13 mol dm−3 htc−. The unusually high quantum yield is explained on the basis of a primary photoredox process followed by a chain reaction involving cobalt(II) species as chain carriers. Cobalt(III) complexes of an N6 donor set such as [Co(NH3)6]3+, [Co(NH3)4(pn)]3+, [Co(chxn)3]3+, and [Co(dien)3]3+ also undergo similar photo-reaction, where pn, chxn, and dien denote 1,2-propanediamine, 1,2-cyclohexanediamine, and diethylenetriamine, respectively.