bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereoselective Synthesis of (E)- or (Z)-α-Alkylidene-γ-butyrolactone from γ-Butyrolactone and Bis[ethoxy(thiocarbonyl)] Disulfide and Mechanistic Studies of the Effect of Metal Complexes on the Stereoselection
Authors: Matsui Syuichi
Published: July 2006

Treatment of γ-butyrolactone with bis[ethoxy(thiocarbonyl)] disulfide in the presence of 2.2 equiv of lithium diisopropylamide (LDA) produced lithium enolate of O-ethyl S-(tetrahydro-2-oxo-3-furanyl) dithiocarbonate, which reacted with an aldehyde to afford exclusively (E)-α-alkylidene-γ-butyrolactone. Interestingly, when the reaction was quenched below −20 °C or when it was carried out in the presence of metal complex such as zinc chloride, copper(I) iodide, or tributyltin chloride, (Z)-α-alkylidene-γ-butyrolactone was obtained as the major product. The stereoselectivity of this reaction was sensitive to the reaction temperature and the metal cation employed.
Stereoelectronic Control in the Hydrolysis of RNA by Imidazole
Authors: Taira Kazunari
Published: July 2006

The cleavage of poly(uridylic acid) by imidazole buffer was studied recently by Breslow and Labelle, and a bell-shaped profile was observed for the rate vs. buffer protonation state. The reaction, however, was kinetically first-order in buffer (R. Breslow and M. Labelle, J. Am. Chem. Soc.,  108, 2655 (1986)). The sequential base-acid mechanism proposed by those authors is in agreement with the expectation based on the stereoelectronic effects. In addition, the alternative sequential acid-base mechanism, which could not be excluded on the basis of their kinetic data, may be excluded based on the stereoelectronic considerations.
Inductively Coupled Plasma Atomic Emission Spectrometric Determination of Copper by Suction-Flow On-Line Liquid–Liquid Extraction of Its Macrocyclic Dioxotetramine Chelate
Authors: Kumamaru Takahiro , Nitta Yoko , Matsuo Hiroshi , Kimura Eiichi
Published: July 2006

The flow manifold described permits suctionflow liquid–liquid extraction of copper(II) in a discrete aqueous sample as its macrocyclic dioxotetramine (6-hexadecyl-1,4,8,11-tetraazacyclotetradecane-5,7-dione, HDC) chelate into chloroform. The organic extract is successively fed into the inductively coupled plasma by a peristaltic pump. The detection limit is 1.5 ng cm−3 copper(II) and the relative standard deviation is 2.2% (n=10) for 100 ng cm−3 copper(II).
Preparation of Isoxazolines by Thermolysis of Ethyl 2-Nitroalkanoates in the Presence of Dipolarophiles
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Shibafuchi Hiroshi , Teramura Kazuhiro
Published: July 2006

3-Alkyl-2-isoxazolines and 3-alkylisoxazole were prepared by thermolysis of ethyl 2-nitroalkanoates at about 230 °C in the presence of dipolarophiles.
Pressure Effect in Syngas Conversion to Ethylene Glycol. A Behavior of Rhodium–Tributylphosphine–N-Methylpyrrolidone System under 1000 atm
Authors: Murata Kazuhisa , Matsuda Akio , Masuda Takashi , Watanabe Eiichi , Wada Keisuke
Published: July 2006

In syngas (CO+H2) conversion to ethylene glycol (EG), rhodium catalyst modified by tributylphosphine (PnBu3) was found to be ca. 20 times more active under 1000 atm at 210 °C than under 500 atm. This unusual pressure effect was discussed on the basis of IR spectral data.
Kinetic Study of Liquid-Phase Esterification with Sulfonic Acid Cation-Exchange Resin of the Macroreticular Type. II. Solvent Effects on Resin Catalysis
Authors: Shimizu Shoichi , Hirai Choichiro
Published: July 2006

The rates of the esterification of octanoic acid with 1-butanol catalyzed by macroreticular sulfonated ion-exchange resin in the presence of various organic solvents and water were measured by the use of a batch reactor. The solvent effects on the rate were investigated by applying the heterogeneous-pseudohomogeneous reaction mechanism. From these results, it was found that the effects can be quantitatively estimated by means of the magnitude of the equilibrium constants, Ksol(S), for the solvent-separated ion-pair formations, which are due to the interaction of the sulfo groups in the resin with the solvents. The correlations of the Ksol(S) value with the physical properties, μ and ε; the solvatochromic parameters, \boldmathπ*, \boldmathα, and \boldmathβ, and Gutmann’s parameters, ANE and DNB, have been examined by using linear regression analysis methods. The results of the correlations in which the protic solvents have been excluded suggest that the positions of the equilibria of solvent-separated ion-pair formations depend mainly on the electron-donor property of the solvents; that is to say, the solvents with a strong donor property diminish the number of un-ionized sulfo groups which act as catalytic species for the heterogeneous reaction.
Stabilization of Platinum-Loaded CdS Photocatalyst by Addition of EDTA
Authors: Matsumura Michio , Ohnishi Hideyuki , Hanafusa Koji , Tsubomura Hiroshi
Published: July 2006

The photocatalytic activity of platinum-loaded CdS powder in sulfite solutions declined by illumination over 200 h, and became half the initial activity at 600 h. By addition of small amount (2 mM) of ethylenediaminetetraacetic acid (EDTA) to the solution, however, the photocatalyst was guarded from deterioration. The effect of EDTA is to prevent the platinum part of photocatalyst from the impurity metal deposition by forming stable metal-EDTA complexes in the solution. The reactivities of sulfite ions, EDTA, and metal-EDTA complexes on illuminated CdS are examined electrochemically by use of CdS-sinter electrodes.
Characteristic Polynomial Expression and Integral Expression for Imaginary Bond–Bond Polarizability. Rules for London Susceptibility and for Ring Current
Authors: Mizoguchi Noriyuki
Published: July 2006

The McWeeny theory for calculating magnetic properties of conjugated hydrocarbons is studied from a graph-theoretical point of view. Imaginary bond–bond polarizability is expressed in terms of characteristic polynomial. The expression clarifies the dependence of imaginary bond–bond polarizability on the structure. It is shown that the expression enables one easily to derive the equations for the quantity proved in two previous papers. The characteristic polynomial expression for imaginary bond–bond polarizability is rewritten in Coulson’s integral form. The rules for London susceptibility and for ring current are proved from the integral expression.
The Effect of the Chain Length and the End-Groups on the Epitaxial Growth of Long-Chain Molecules
Authors: Ueda Yasukiyo
Published: July 2006

Five paraffins (C30–C44) and three linear compounds with polar end-groups, such as hydroxyl, methyl-ester, and carboxyl groups, were deposited on the cleavage surface of an alkali halide crystal in vacuo. Paraffin films deposited on the substrate took the same crystal structure and molecular orientation, independent of the number of carbon atoms in the chain. In the case of derivatives, the morphology and orientation of the crystals, however, differed with the end-groups. The (110) planes of paraffins, alcohol, and methyl-ester crystals were oriented parallel to the substrate (001) plane, and their c-axes were parallel to the [110] direction of the substrate crystal. On the other hand, the (001) plane of the acid crystal lay parallel to the substrate surface, so that the c-axis of the crystal was oblique to the substrate surface. The epitaxial growth of linear molecules with different end-groups was explained by the difference in the interaction between the end-groups and the substrate.
Microenvironmental Effects of Water-Soluble Polymers on the Chemiluminescence of Luminol and Its Analogs
Authors: Karatani Hajime
Published: July 2006

The effects of water-soluble polymers(WSPs), such as bovine serum albumin(BSA) and polyethylenimine(PEI), on chemiluminescence(CL) in an aqueous solution have been studied. The CL emission, particularly in the initial stage of the CL reaction, was strongly enhanced by increasing the concentrations of these WSPs. This was attributed to the acceleration of the chemical reactions prior to the formation of the light-emitting species. BSA was also peculiar in that it could enhance CL under neutral pH conditions. It was suggested that these WSPs offered hydrophobic and basic microenvironments well suited to the CL reaction.
The Wetting of an Alumina Substrate by Liquid Silver
Authors: Ushio Masumi , Sumiyoshi Yoshihiro
Published: July 2006

The wetting of the Al2O3 substrate by liquid silver was investigated by means of the sessile-drop technique in an atmosphere of argon. An empirical relation was established between the contact angle and the temperature or surface tension of the liquid drop by the use of the diameter and the height of the sessile drop. The contact angle was constant as the time increased while it decreased linearly with the increase in the temperature. The variation in the contact angle with the temperature is correlated with the surface tension of the sessile drop. The critical surface tension (γc) of Al2O3 is 361 dyn cm−1, while the surface tension of liquid silver at 0 K is 790 dyn cm−1.
Prediction of Dissociation Constants of Ammonium Ion in Artificial Seawaters and in Concentrated Sodium Chloride Solutions
Authors: Maeda Masunobu , Hayashi Masato , Ikeda Shoichiro , Kinjo Yoshiaki , Ito Kaname
Published: July 2006

The dissociation constants of ammonium ion were determined at 25°C by potentiometry with glass and ammonium-ion-selective electrodes in artificial seawaters at various salinities (25–45\ extperthousand) and in concentrated sodium chloride aqueous solutions (0.72–3.2 mol kg−1). The activity coefficients of ammonia in sodium chloride solutions of the same ionic strengths as those of the artificial seawaters and in the concentrated sodium chloride solutions, which were used for the theoretical estimation of the dissociation constants, were measured by a transpiration method. The dissociation constants were theoretically evaluated in terms of the ionic interaction model developed by Pitzer and co-workers, and compared with the experimental ones. The predicted dissociation constants showed a good agreement with the observed ones.
Correlation of Oxidation and Reduction Potentials of Reactants with Product Distribution in the Reactions of Various Organomagnesium Reagents with Aromatic Carbonyl and Nitro Compounds
Authors: Okubo Masao , Tsutsumi Toshiki , Matsuo K\={o}ji
Published: July 2006

In the electron transfer initiated fifteen reactions of five organomagnesium reagents, a semiquantitative relationship between the product distribution and the electron-donating and -accepting abilities (EDA and EAA) of reactants was obtained. The EDA was estimated by cyclic voltammetry of oxidation peak potentials of reagents and/or by the product distribution in their reactions, the decreasing order of EDA being: ArMgBr>ArSMgBr>ArNHMgBr>ArN(MgBr)2>ArOMgBr. The EAA of six quinones, eight nitroarenes, eleven aromatic ketones and an imine, and five azoxyarenes were similarly estimated by their reduction potentials (redox) in THF. The values of differences between the oxidation peak and reduction potentials were taken as an estimate of the relative efficiency of electron transfer, and were correlated to the distribution of normal (addition, condensation, replacement, and azoxy-deoxygenation) and abnormal (radical) products. Some exceptional cases were explained by modifying EDA and/or EAA based on the effect of coordination of substrate’s oxygen to reagent’s Mg atom.
Syntheses of Optically Active Pentaacetates of Pseudo-β-l-allopyranose and Pseudo-α-d-mannopyranose
Authors: Tadano Kin-ichi , Fukabori Chiyoko , Miyazaki Masayuki , Kimura Hiroshi , Suami Tetsuo
Published: July 2006

Diisobutylaluminium hydride reduction of d-glucose-derived chiral synthon, (1R,6R,8R,9R)-8,9-isopropylidenedioxy-7-oxabicyclo[4.3.0]non-4-en-3-one (1), gave a 7:1 mixture of (1R,3S,6R,8R,9R)- and (1R,3R,6R,8R,9R)-8,9-isopropylidenedioxy-7-oxabicyclo[4.3.0]non-4-en-3-ol, (2) and (2′). Introduction of cis-diol to the double bond of 3-O-acetyl derivatives of 2 and 2′ by osmium tetraoxide oxidation provided the diastereomeric mixture of (1R,3S,4R,5S,6S,8R,9R)-3-acetoxy-8,9-isopropylidenedioxy-7-oxabicyclo[4.3.0]nonane-4,5-diol (5) and (1R,3R,4S,5R,6S,8R,9R) diastereomer. Compound 5 was transformed to optically active pseudo-β-l-allopyranose effectively via (1R)-1-[(1S,2S,3S,4R,5S)-3,4,5-tris(benzyloxy)-2-hydroxycyclohexyl]-1,2-ethanediol (9). Cyclohexanecarbaldehyde formed by glycol cleavage of 9 was treated with methanesulfonyl chloride and reduced with lithium aluminium hydride to give (3S,4R,5S)-3,4,5-tris(benzyloxy)-1-cyclohexene-1-methanol (13). Compound 13 was efficiently converted to pseudo-α-d-mannopyranose pentaacetate by stereoselective hydroboration as a key reaction. The Wharton reaction of (1R,4S,5S,6S,8R,9R)-4,5-epoxy-8,9-isopropylidenedioxy-7-oxabicyclo[4.3.0]nonan-3-one derived from 1 gave(1R,5R,6S,8R,9R)-8,9-isopropylidenedioxy-7-oxabicyclo[4.3.0]non-3-en-5-ol, into which (3S,4S)-diol was stereoselectively introduced by oxidation with osmium tetraoxide.
A Solvent-Extraction Study of the Hydrolysis of Tracer Concentrations of Bismuth(III) in Chloride Solutions
Authors: Suganuma Hideo , Shimizu Itaru , Hataye Itsuhachiro
Published: July 2006

The backward solvent extraction with dithizone(H2dz)–CCl4 solutions was used to examine the chemical species of bismuth(III) in 1 mol dm−3 of a (H,Na)Cl solution. A tracer concentration of bismuth(III) (ca. 10−11 mol dm−3) was found to exist mainly in the form of [BiCl5]2−, [BiCl5(OH)]3−, [BiCl4(OH)]2−, and [BiCl3(OH)3]3− in the (H,Na)Cl solutions. The constants of the successive hydrolysis, β1, β2, and β3, were calculated by using the distribution data. The resulting logβ1, logβ2, and logβ3 values were 10.9, 17.5, and 30.2 respectively. The chemical composition of the extracted species was most probably [Bi(Hdz)3].
Sulfur Contents of Volcanic Rocks in Japan
Authors: Arikawa Yoshiko
Published: July 2006

The total sulfur content was determined for 140 samples of Japanese volcanic rock by the mercury(II) thiocyanate photometric method of hydrogen sulfide formed by a wet reduction of the sample by tin(II)–strong phosphoric acid. Though determined values are widely scattered from 5390 down to 10 ppm (or less), the cumulative frequency distribution of the sulfur contents shows lognormality. The geometric and arithmetic means are 26 ppm (mg kg−1) and 116 ppm, respectively. The alkaline rocks have high sulfur contents, the geometric mean of which is 62 ppm. Little significant difference was observed among the rhyolitic rock, the andesite and the trachyte, and the basaltic rock. Japanese and foreign standard rock samples were analyzed for sulfur. Almost all results were in good agreement with those obtained by other authors. In this case foreign standard samples also have higher sulfur contents than those of Japanese samples. The fact that the sulfur contents of Japanese volcanic rocks are lower than the previously accepted values seems to be characteristic of the islands arc of volcanism.
Raman Spectra of Tris(bidentate)cobalt(III) Complexes Containing 1,3-Propanediamine and β-Alaninate
Authors: Kawamoto Tatsuya , Einaga Hisahiko , Hidaka Jinsai
Published: July 2006

The Raman spectra of the tris(bidentate)cobalt(III) complexes containing the six-membered tn and/or β-ala chelate ring, where tn and β-ala denote 1,3-propanediamine and β-alaninate respectively, were measured in order to investigate the relation between the Raman spectra and the structures of the complexes. The Raman bands can be classified into four vibration modes: A totally symmetric stretching vibration mode in the 440–640 cm−1 region, a stretching vibration mode excluding the totally symmetric one in the 380–480 cm−1 region, a metal-ligand skeletal bending deformation mode in the 260–400 cm−1 region, and a chelate ring deformation mode in the 220–290 cm−1 region. The present complexes characteristically exhibited more Raman bands than the complexes with the five-membered chelate rings in the totally symmetric stretching vibration mode. For the [Co(β-ala)2(tn)]+ complex, the three geometrical isomers, trans(O), C2-cis(O), and C1-cis(O), which were prepared for the first time, each exhibited characteristic Raman spectral features.
The Complexing of the Magnesium and Barium Ions in Acetonitrile with Other Solvents. Investigation by the Use of a Polyacrylamide-Tetraethylene Glycol Monododecyl Ether Membrane Ion-Selective Electrode
Authors: Nakamura Toshio , Higuchi Hisakazu , Izutsu Kosuke
Published: July 2006

The complexations of magnesium and barium ions in acetonitrile with DMF, DMSO, and HMPA were studied potentiometrically by the use of an organic polymer membrane electrode. The formation constants for 1:1 complexes of magnesium and barium ions, respectively, were 2.1×102 and 19 with DMF, 4.5×102 and 41 with DMSO, and (5.5×103) and 1.6×103 with HMPA. The roles of the basicity of the complexing solvent, crystallographic radius, and charge of the cations are discussed briefly.
The Crystal Structure of Phenanthrene: Picric Acid Molecular Complex
Authors: Yamaguchi Shin-ichi , Goto Motoaki , Takayanagi Hiroaki , Ogura Haruo
Published: July 2006

The crystal structure of phenanthrene:picric acid molecular complex was determined by X-ray crystal analysis. Phenanthrene and picric acid molecules are stacked alternately along the c-axis, making their molecular planes parallel to each other. The intramolecular hydrogen bonding exists in a picric acid.
Shape Selectivity of ZSM-5 Type Zeolite for Alkylation of Ethylbenzene with Ethanol
Authors: Kim Jong-Ho , Namba Seitaro , Yashima Tatsuaki
Published: July 2006

The alkylation of ethylbenzene with ethanol on ZSM-5 zeolites was studied at 673 K. The primary product in this alkylation on HZSM-5 catalyst was only p-diethylbenzene because of the transition-state selectivity. Therefore, the isomerization of p-diethylbenzene has to be restrained for the selective formation of p-diethylbenzene. The modified HZSM-5 catalysts with oxide of magnesium, phosphorus or boron showed much higher para-selectivity than the parent HZSM-5. The modification reduced not only the effective pore dimension of HZSM-5 but also the amount of strong acid sites. We claim that the absence of strong acid sites is necessary rather than the narrowness of pores for the suppression of the isomerization of p-diethylbenzene produced as a primary product.
Photooxidation of the Evaporated Films of Polycyclic Aromatic Hydrocarbons Studied by X-Ray Photoelectron Spectroscopy
Authors: Yamada Masamichi , Ikemoto Isao , Kuroda Haruo
Published: July 2006

Photooxidations of the evaporated films of rubrene, naphthacene, and pentacene were investigated by means of X-ray photoelectron spectroscopy. A rubrene film was found to be photooxidized far more easily than a naphthacene film although the molecules of rubrene and naphthacene in solution are known to be almost equally reactive for photooxidation. Although pentacene is photooxidized very easily in solution, the oxidation rate of a pentacene film was little enhanced by the light irradiation. Discussion is given on these behaviors of the evaporated films by considering the molecular packing in the solid state and the mechanism of photooxidation.
The Effects of the Sol–Gel Transition of Alginates on Effective Charge Densities
Authors: Yonese Masakatsu , Baba Kazuhiko , Kishimoto Hiroshi
Published: July 2006

The counterion binding properties of alginate (Alg) sol and gel were studied by using the membrane potential method, in which membranes were constructed of an Alg layer sandwiched between supporting films. The concentrations of Alg WAlg ranged from 0.0025 to 0.0063 g cm−3, and the membrane potentials were measured in NaCl, MgCl2, and CaCl2 solutions. The effective charge densities of Alg (θ*2) were obtained by curve fittings with the theoretical values of the multimembrane potentials. The ratios of θ*2 to the concentration of uronate units θ0 were found not to depend on WAlg; their mean values were 0.45, 0.28, and 0.12 for Na-, Mg-, and CaAlg. The results of Na- and MgAlg in the sol state were bigger than Manning’s theoretical values. The much smaller values of CaAlg in the gel state than MgAlg in the sol state showed that the Ca ion binding was enhanced by the gellation not only in the junction, but also in the networks.
The Crystal and Molecular Structures of N-Phenyl-4-nitrobenzylamine, N-Phenyl-4-nitrophenethylamine, and N-Methyl-N-p-tolyl-4-nitrophenethylamine
Authors: Iwasaki Fujiko , Masuko Yoshiaki , Monma Sachiko , Watanabe Toshiya , Mutai Kiyoshi
Published: July 2006

The crystal and molecular structures of N-phenyl-4-nitrobenzylamine (1), N-phenyl-4-nitrophenethylamine (2), and N-methyl-N-p-tolyl-4-nitrophenethylamine (3) have been determined by the X-ray method. The crystals of 1 are monoclinic, P21/n, a=16.924(1), b=8.792(1), c=7.642(1) Å, β=91.59(1)°, V=1136.8(1) Å3, Z=4, Dx=1.334 Mg m−3. 2 is triclinic, P\bar1, a=15.106(1), b=9.573(1), c=9.427(1) Å, α=113.22(1), β=91.27(1), γ=83.61(1)°, V=1244.7(2) Å3, Z=4, Dx=1.293 Mg m−3. 3 is trigonal, P31, a=b=8.435(1), c=17.758(1) Å, α=β=90°, γ=120°, V=1094.2 Å3, Z=3, Dx=1.231 Mg m−3. The final R values are 0.064, 0.059, and 0.045 for 1625, 3606, and 1131 observed reflections of 1, 2, and 3, respectively. About the amino-methylene N–C bond the phenyl group is trans to C for the molecules of 1 and 2, while in 3 the phenyl group is gauche to C about the N–C bond. The nitrophenyl plane of 3 is stacked on the p-toluidino plane of the neighbouring molecule alternately with the mean distance of 3.40 Å. The presence of the intermolecular CT interaction of 3 has been confirmed by the electronic absorption spectra of these compounds in the solid state.
Dielectric Loss of Dehydrated Rb3Na8–ZK4 Zeolite
Authors: Ohgushi Tatsuo
Published: July 2006

The dielectric properties of completely dehydrated Rb3Na8–ZK4 zeolite were studied in the range 12–2.2×106 Hz and 211–705 K. Two kinds of losses, relaxation and conduction, were observed. The relaxation loss in the higher-frequency region had an activation energy of 99±2 kJ mol−1 and was tentatively assigned to a jump of the Rb+ ion from an 8-ring site to a vacant 4-ring site. The loss at the lower-frequency region had an activation energy of 95±3 kJ mol−1 and was attributed to a movement of the Rb+ ion on the 8-ring site beyond the unit-cell dimension.
Reflectance Spectra of the 1:1 Salts of Bis(methylenedithio)tetrathiafulvalene (BMDT-TTF): Estimation of the On-Site Coulomb Energy
Authors: Yoshitake Michiko , Yakushi Kyuya , Kuroda Haruo , Kobayashi Akiko , Kato Reizo , Kobayashi Hayao
Published: July 2006

Polarized reflectance spectra were measured on the single crystals of (BMDT-TTF)AsF6 and (BMDT-TTF)SbF6. The charge-transfer band was observed along the stacking direction in the crystals of (BMDT-TTF)AsF6, while in the crystal of (BMDT-TTF)SbF6 the charge-transfer band was found not only along the stacking direction but also along the S···S direction nearly parallel to the short axis of the BMDT-TTF molecule. The effective on-site Coulomb energies and the transfer integrals of these salts were estimated by analyzing the charge-transfer bands.
Effects of Compositional Changes of Hot Spring Water upon Mineral Precipitate. I. Changes in Chemical Composition and Crystal Growth Rate of Pb-Bearing Barite (Hokutolite) from Tamagawa Hot Spring Waters
Authors: Sasaki Nobuyuki , Watanuki Kunihiko
Published: July 2006

Changes in the chemical compositions of Tamagawa Hot Spring waters and Pb-bearing barite (hokutolite) were examined. Samples were obtained from various locations and various time in Tamagawa Hot Spring. The relationships between the hot spring waters and the minerals were expressed as partition equations and phenomenological equations; then, the partition coefficients and phenomenological coefficients were calculated. The apparent partition coefficients of Pb2+ and of Sr2+ between the two phases were found to have increased, from 0.14 to 0.30(0.31) and from 0.023 to 0.035(0.042) respectively, with the decrease in the hokutolite growth rate since 1973. The reaction rate of hokutolite as calculated from the phenomenological equations was, however, about 2 times higher in 1983 than in 1965. These results were ascribed to the rise in the degree of the supersaturation of barium sulfate and also to the increase in the nucleation rate in the hot spring water.
Interfacial Adsorption of 1,10-Phenanthroline Complexes in Solvent Extraction Systems
Authors: Watarai Hitoshi , Horii Yoko , Fujishima Mitsuaki
Published: July 2006

A significant adsorptivity of tris(1,10-phenanthroline)iron(II), [Fe(phen)3]2+, at the interface of chloroform or carbon tetrachloride/0.1 M aqueous sodium chloride systems was determined by means of interfacial tension measurements at 25 °C. In the distribution systems of phen containing Zn(II) or Cu(II), a characteristic interfacial tension lowering was observed and interpreted in terms of an interfacial adsorption of metal–phen complexes.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XIV. Examination of Rates of Proton-Detachment from Ammonium Ions with Multiple Probes
Authors: Morita Toshiari , Oki Michinori
Published: July 2006

The rates of proton-detachment and those of topomerization in ammonium ions of benzyldiethylammonium chloride and benzylisopropylmethylammonium chloride were determined by dynamic NMR spectroscopy, by taking advantage of loss of coupling of the benzylic methylene or the methyl protons for the former process and site-exchange of the diastereotopic protons at the ethyl-methylene, isopropyl-methyl, or benzylic methylene positions for the latter in 1H NMR spectroscopy. The rates of the both processes were in good agreement with each other to indicate that the rate-limiting process in the observed topomerization is the proton-detachment. Thus it is shown that any available probes may be used for the proton-detachment or for the ivestigation of the proton affinity of amines by the dynamic NMR spectroscopy in aprotic solvents. The preference of the probes was discussed.
Synthetic Studies on Germacranolides: Synthesis of Optically Active 3-Benzoyloxy-6-oxo-13-nor-12,8-heliangolide
Authors: Utagawa Akiko , Hirota Hiroshi , Ohno Shigeru , Takahashi Takeyoshi
Published: July 2006

Optically active (3R,7R,8R,1(10)E,4Z)-3-benzoyloxy-6-oxo-13-nor-1(10),4-germacradieno-12,8-lactone, a key synthetic intermediate for naturally occurring hiyodorilactone A, was prepared from (−)-carvone.
Cycloaddition Reactions of 2-Hydroxy-, 2-Amino-, and 2-Mercapto-1-azaazulenes with Reactive Acetylenes
Authors: Abe Noritaka , Takehiro Toshiyuki
Published: July 2006

The reaction of 1-methyl-1-azaazulen-2(1H)-one (1a) with dimethyl acetylenedicarboxylate (DMAD) or dibenzoylacetylene (DBA) in refluxing acetonitrile gave 1,2-disubstituted azulene (2), 2-methylcyclopent[de]isoquinolin-3(2H)-ones, 1-methyl-1-azacyclopent[cd]azulen-2(1H)-ones, and 3-substituted 1-methyl-1-azaazulen-2(1H)-ones, whereas in refluxing t-butylbenzene, compound 2 and 6,8-etheno-1-methylcyclohepta[b]pyrrol-2(1H)-one were obtained as major products. The reactions proceeded periselectively depending on the temperature. 2-Hydroxy-1-azaazulene behaved as 1-azaazulen-2(1H)-one and the reaction with DMAD gave similar result as for 1a. The reaction of 2-amino-1-azaazulene with DMAD gave methyl 2,4a-dihydro-2-oxo-1,4a-diazabenz[a]azulene-4-carboxylate and tetramethyl 4,5-dihydro-1H-1,11-diazacyclohept[a]azulene-2,3,4,5-tetracarboxylate. The reaction of 2-mercapto-1-azaazulene with DMAD gave tetramethyl 4,4a-dihydro-4a-azabenz[a]azulene-1,2,3,4-tetracarboxylate in moderate yield. The reaction mechanisms of these reactions are discussed.
The Synthesis of a Double-Layered Annulene with 10π-Rings. 1,1:2,2-Bis([10]annulene-1,6-diyl)ethylene
Authors: Yamamoto Koji , Ojima J\={u}ro , Morita Noboru , Asao Toyonobu
Published: July 2006

The synthesis of the title compound, a double-layered annulene with 10π-rings, is described. The examination of 1H NMR and electronic spectra suggests that the layered compound exhibits appreciable interaction between two [10]annulene rings.
Synthesis of 2-Benzylidene-3(2H)-benzofuran-3-ones (Aurones) by Oxidation of 2′-Hydroxychalcones with Mercury(II) Acetate
Authors: Sekizaki Haruo
Published: July 2006

The reaction of 2′-hydroxychalcones with mercury(II) acetate in acetic acid gives predominantly 2-benzylidene-3(2H)-benzofuran-3-ones (aurones) in 28–62% yield accompanied by flavanones in 5–21% yield.
Stereoselective Synthesis of 3,5-Alkadienoic Esters from 2,4-Dienoic Isomers
Authors: Tsuboi Sadao , Sakamoto Jun-ichi , Kuroda Akihisa , Utaka Masanori , Takeda Akira
Published: July 2006

The treatment of (2E,4Z)-2,4-alkadienoic esters with lithium diisopropylamide (LDA) at −80 °C gave (3E,5E)-isomers with 81–98% stereoselectivity. In contrast, the treatment of (2E,4E)-isomers under the same conditions gave (3E,5Z)-isomers with 72–80% stereoselectivity. The application to the synthesis of megatomoic acid is described. Carbon-13 NMR data regarding these 3,5-dienoates were obtained.
Unusual Concentration–Rate Profiles for Oxidation of a Pair of Associating Thiols
Authors: Kato Jun-ichi , Ito Masato M , Hagino Kazuomi , Naitoh Narumi , Misaka Makoto , Fujishiro Einosuke , Endo Tadashi
Published: July 2006

In base-catalyzed oxidation of a pair of associating thiols [HSCH2–CONHCONH–Ph and HSCH2CH2NHCONHCO–C6H13] with oxygen, there are concentration regions where initial rates decrease with increasing concentrations of the thiols. For a pair of nonassociating thiols [HSCH2CO2C2H5 and HSCH2CH2OH], initial rates increase linearly with concentrations of the thiols.
Catalytic Activity of catena-μ-Cyano-(phthalocyaninato)cobalt(III) for the Cathodic Reduction of Oxygen
Authors: Ikeda Osamu , Itoh Shuji , Yoneyama Hiroshi
Published: July 2006

catena-μ-Cyano-(phthalocyaninato)cobalt(III) showed a 4-electron reducibility for the cathodic reduction of oxygen at low overpotentials, which was not observed for (phthalocyaninato)cobalt(II) and chloro(phthalocyaninato)cobalt(III).
The Adsorption of Cholesterol and Egg-Lecithin from Solutions on Active Carbon
Authors: Zhao Zhenguo , Wu Aiyin , Gu Tiren , Ma Yuanming
Published: July 2006

The adsorption isotherms of cholesterol from ethanol and cyclohexane (at 25 and 35 °C), and of egg-lecithin from ethanol and ethanol–water mixed solvent (at 25 °C) onto active carbon have been determined. The isotherms can be represented by Dubinin–Radushkevich equation. The results indicate that the adsorption of cholesterol and lecithin from solutions onto active carbon can be explained by the mechanism of micropore filling.
Chlorothionitrene Complexes of Tungsten. Synthesis, Characterization, and Chemical Behavior of Tungsten(VI) Thionitrene Complexes
Authors: Seth Jyoti , Gupta Minu , Agarwala U C
Published: July 2006

The syntheses of Tungsten(VI) chlorothionitrene complexes have been described and their chemical behavior was studied. The compounds were characterized by microanalyses, vibrational, electronic, ESR, NMR spectral and other Chemical studies.
A Simulation of Bromate–Cerium–Oxalic Acid Oscillations
Authors: Sasaki Yoshihiro
Published: July 2006

The oscillation behavior of the bromate–cerium–oxalic acid system was simulated within the FKN framework with bromine-hydrolysis control, where a radical-chain reaction of HOBr with oxalic acid and the formation of HCO2· by the reduction of Ce(IV) were assumed. When [(COOH)2]=0.03 mol dm−3 and k13=0.075 s−1 (k13: the rate constant of bromine removal), the oscillation behavior was qualitatively consistent with the experimental results. Excitability in the reduced and oxidized steady states, induced by a sudden change in the concentration of bromine, was simulated. No bistability was found. When [(COOH)2]=0.03 mol dm−3, no hysteresis near the bifurcation points was observed. However, when [(COOH)2]=0.001 mol dm−3, hysteresis was observed in the transition between the oxidized steady state and the oscillatory state.
ESR Study on the Reactions of 1,3-Diene Cation Radicals in Low-Temperature Matrices
Authors: Fujisawa Jun , Takayanagi Toshiyuki , Sato Shin , Shimokoshi Kazuo
Published: July 2006

The reactions of the cation radicals of 1,3-butadiene, cis- and trans- 1,3-pentadienes, 2-methyl-1,3-butadiene, and 2,3-dimethyl- 1,3-butadiene have been investigated by low-temperature matrix ESR. The cation radicals produced in the irradiated solid solutions of CCl2FCCl2F were found to react with their neutral parents at temperatures above ca. 110 K, forming radicals with allylic ends. On the other hand, 1,3-pentadiene cation radicals in the matrices of CCl4, CCl3F, and CCl3CF3 were found to isomerize into cyclopentene cation radicals, irrespective of the cis and trans forms. The possible mechanisms for the reactions and their implications in the cationic polymerization of dienes are discussed.
Preparation of Fluorine-Containing Phenylacetylenes by the Method of Introduction of the Ethynyl Group Using 1,1-Dichloro-2,2-difluoroethene
Authors: Kodaira Kazuo , Okuhara Kunio
Published: July 2006

Phenylacetylenes (ArC≡CH) having fluoro- or trifluoromethyl substituents (o-, m-, p-F; o-, m-, p-CF3; 2,4-, 2,5-, 2,6-, 3,5-(CF3)2) have been prepared from bromobenzenes (ArBr) and benzenes (ArH) using 1,1-dichloro-2,2-difluoroethene (1) by a two-step route: ArLi or ArMgBr→ArCF=CCl2→ArC≡CLi. Upon careful treatment at −70 °C with 1, o-fluorophenyllithium gave o-FC6H4CF=CCl2 in good yield, together with benzyne-derived products, such as o-(o-FC6H4)C6H4CF=CCl2. Lithiation of m-bis(trifluoromethyl)benzene at 0 °C for 9 h (24 h) followed by treatment with bromine gave 1-bromo-2,4-, 2,6-, and 3,5-bis(trifluoromethyl)benzene in 35 (38), 31 (36), and 8% (6%) yield, respectively.
Homolytic Decomposition of t-Alkyl 2,2-Dimethylperoxypropionates
Authors: Komai Takeshi , Matsuyama Kazuo , Matsushima Masaru
Published: July 2006

Decomposition rates and products of t-alkyl 2,2-dimethylperoxypropionates were measured in cumene at several temperatures. The peroxyesters decomposed homolytically, depending on the structure of the t-alkyl moiety. The relative rates of the t-alkyl moieties to the 1,1-dimethylethyl one were: 1,1-dimethylbutyl (1.14), 1,1-dimethylpropyl (1.19), 1,1,2-trimethylpropyl (1.85), 1,1,3,3-tetramethylbutyl (2.10), and 1,1-dimethyl-2-phenylethyl (2.34). The decomposition showed an isokinetic relationship and the importance of stabilization by hyperconjugation. Based on these data, the decomposition mechanism, which contains a slight stretching of the Cα–Cβ bond to the peroxyl oxygen at the transition state is, discussed.
Oxidoreduction between Cycloalkanols and the Corresponding Cycloalkanones in the Cultured Cells of Nicotiana tabacum. Simulation of the Time Courses in the Oxidoreduction
Authors: Izumi Shunsuke , Suga Takayuki
Published: July 2006

A method for the simulation of the time courses in the oxidation of cycloalkanols and the reduction of cycloalkanones in the cultured cells of Nicotiana tabacum was developed on the basis of the permeability of these compounds into the cultured cells and the 13C NMR chemical shift of the carbonyl carbon of the cycloalkanones. Further, the method has been applied to the simulation of the time courses in the oxidation of (+)-borneol and (+)-isopinocampheol and the reduction of (−)-carvomenthone in the cultured cells of N. tabacum.
The Effect of the Heat Treatment of Pd Thin Film Alloy on the Hydrogenation of Olefins
Authors: Tamaki Jun , Yamamura Masashi , Imanaka Toshinobu
Published: July 2006

Pd–(B, P) thin film alloys have been prepared by an RF sputtering method. Before heat treatment, the selectivity for the partial hydrogenation of olefins increased with the increase in the B or P concentration in the Pd–(B, P) films. After the heat treatment, on the other hand, the selectivity for the partial hydrogenation was reduced over the Pd films with a low B or P concentration. However, in the case of the Pd films with a high B or P concentration, the selectivity was enhanced by the heat treatment. The high selectivity after the heat treatment was explainable in terms of the small ensemble size, the low electron density of Pd, and the appearance of a Pd3B, Pd4.8P, or Pd5P2 phase in the Pd films with a high B or P concentration. A sputtered film is known to have a columnar structure. This columnar structure was deduced to be controlled both by the alloying of Pd with B or P and by the heat treatment, so as to exhibit the high selectivity for the partial hydrogenation of olefins.
Second Virial Coefficients of Axially Symmetric Molecules
Authors: Boushehri Ali , Attaran A Mohammad
Published: July 2006

The paper presents a contribution to the second virial coefficient due to the asphericity of the molecular charge distribution. This contribution is conveniently divided into terms representing the classical electrostatic interaction between the two charge distributions, the anisotropy of dispersion forces, and the shape of the molecular core. These are considered quantitatively. Results from recalculating the nonspherical contributions to the second virial coefficients with a good spherical core are obtained from statistical mechanics and applied to the CO2 gas. Explilcit formulas are given for the simple cases of axially symmetric molecules.
Kinetic Study of the Oxidation of Substituted Benzyl Alcohols by Ethyl Chlorocarbamate
Authors: Jain (nee Mittal) Suman , Banerji Kalyan K
Published: July 2006

The kinetics of the oxidation of twenty-four monosubstituted benzyl alcohols by ethyl chlorocarbamate (ECC) have been studied in aqueous acetic acid solution, in the presence of perchloric acid. The main product of the oxidation is the corresponding benzaldehyde. The reaction is first order with respect to the alcohol, ECC, and hydrogen ion. The oxidation of [α,α-D2]benzyl alcohol indicated a primary kinetic isotope effect, kH⁄kD=5.40 at 298 K. The value of solvent isotope effect, k(H2O)/k(D2O), is 1.85 at 298 K. Addition of ethyl carbamate does not affect the reaction rate. [EtOC(OH)NHCl]+ has been postulated as the reactive oxidizing species. The rates of oxidation of para- and meta-substituted benzyl alcohols show excellent correlation in Taft’s dual substituent parameter equation, with negative reaction constants. The rates of the ortho-substituted compounds correlate well in Charton’s equation of inductive, resonance and steric substituent parameters. A mechanism involving simultaneous transfer of a hydride ion from the C–H bond and of a proton from the O–H bond to the oxidant is proposed.
Liquid Crystalline Catalysis. Kinetics of the Rearrangement of Allyl p-(Dimethylamino)benzenesulfonate in a Smectic B–Solvent
Authors: De Maria Paolo , Samorì Bruno , Tampieri Anna , Zani Paolo
Published: July 2006

Allyl p-(dimethylamino)benzenesulfonate (ASE) was found to promptly rearrange to the corresponding quaternary zwitterion (AZWI) in a smectic, liquid crystalline solvent (OS 35) 4-pentylcyclohexyl 4-propylcyclohexanecarboxylate. On the contrary, this reaction does not occur in isotropic solvents. In the present study we investigate the effect of temperature and of reactant concentration on the reaction rate. A plot of logk vs. 1⁄T shows a strog upward curvature. In addition, the rate constant, k, strongly depends on ASE concentration: relevant rate depression occurs beyond a threshold value of solute concentration, which in turns depends on temperature. These results are interpreted in terms of reaction mechanism and solute–solvent interaction. From these results we can conclude that smectic B phase has a strong catalytic effect on this particular kind of nucleophilic displacement. Furthermore, catalysis does not depend on solute expulsion from the bulk of the phase; finaly, the detailed mechanism of the catalytic effect may depend on the different location of the solute in distinct solubilization sites existing within the smectic mesophase.
Molecular Rearrangements. XXIX. Thermolysis of Aromatic Ketoximes
Authors: Badr M Z A , Aly M M , Mahgoub S A , Fahmy A M , Atallah A A
Published: July 2006

Thermolysis of benzophenone O-benzoyloxime leads to the formation of NH3, CO2, benzene, biphenyl, benzophenone, benzanilide, benzonitrile, benzoic acid, 2-phenylbenzoxazole, salicylaldehyde and its p-isomer. Analogous results were also obtained on thermolysis of acetophenone O-benzoyloxime. Similarly, benzophenone and/or acetophenone O-benzyloximes give pyrolysis products of the same nature in addition to others corresponding to the benzyl moiety. Thermolysis of deoxybenzoin oxime gives NH3, toluene, benzonitrile, bibenzyl, benzil, benzyl alcohol, and 2-phenylindole. Moreover, its O-benzoyl ether affords in addition to these products, benzoic acid and benzyl benzoate. The main feature of these pyrolyses is the homolysis of the N–O bond together with either O-benzyl or O-benzoyl bonds providing free radicals that undergo different reactions involving H-abstraction, dimerization, fragmentation, rearrangement and cyclization to form the identified products.
The Crystal and Molecular Structure of μ-Oxo-bis[bromotriphenylantimony(V)], [SbBr(C6H5)3]2O
Authors: Ouchi Akira , Sato Shoichi
Published: July 2006

The crystal and molecular structure of the title complex was determined by the single-crystal X-ray diffraction method. The crystallographic data are: monoclinic, space group P21⁄c, a=19.164(6), b=19.020(9), c=18.649(7) Å, β=95.06(3)°, and Z=8 (16 metal atoms are in a unit cell). There are two crystallographically independent dimeric [SbBr(C6H5)3]2O molecules, which are almost in the same form. Each antimony atom is bonded with three phenyl carbon atoms equatorially and one bromine as well as one bridging oxygen atoms axially, being in a trigonal-bipyramidal geometry. The Sb–O–Sb′ angles are 170.2(7) and 176.6(8)°, while the Sb–O lengths are in the range of 1.931(13)—1.958(13) Å, which are shorter than the sum of their covalent radii of the atoms: 2.15 Å.
Thermal Cis–Trans Isomerization of Dihalogenobis[trialkyl(or aryl)phosphine]platinum(II) in the Solid State
Authors: Fushimi Masaki , Suzuki Masatatsu , Uehara Akira
Published: July 2006

Solid-state thermal cis–trans isomerization of the platinum(II) complexes of the type [PtX2(PR3)2] were investigated by means of DSC methods, where X is Cl, Br, or I; R is CH3, C2H5, n-C3H7, n-C4H9, or C6H5. High isomerization ratios (93–100%) were observed for the cis complexes of P(C2H5)3 (X: Br; I), P(n-C3H7)3 (X: Br; I), and P(n-C4H9)3 (X: Cl; Br).
The Magnetic Properties of the Copper(II) Alkanoate Adducts with Cyclic Ethers and Tertiary Amines
Authors: Emori Shuji , Nonaka Hiroki , Ikeda Noriyasu , Muto Yoneichiro
Published: July 2006

Various copper(II) alkanoate adducts with cyclic ethers and tertiary amines have been prepared and characterized by means of magnetic susceptibility and IR spectroscopy measurements. The effect on the magnetic moments of the dinuclear copper(II) alkanoates of varying the base strength of the axial ligands is also discussed.
A Convenient Synthesis of 2-t-Alkyldioxy-2-methyl-1-propanols
Authors: Higuchi Yoshiki , Matsuyama Kazuo , Komai Takeshi
Published: July 2006

Several 2-t-alkyldioxy-2-methyl-1-propanols have been synthesized conveniently by a ring-opening reaction of 1,2-epoxy-2-methylpropane with t-alkyl hydroperoxides in the presence of halogenated acetic acid catalysts.
Crystal Structures and Electronic Properties of Organic Conductors Based on AzaTCNQ
Authors: Urayama Hatsumi , Inabe Tamotsu , Mori Takehiko , Maruyama Yusei , Saito Gunzi
Published: July 2006

AzaTCNQ ((4-dicyanomethyl-1-pyridinio)dicyanomethanide) is employed as an organic acceptor to form new organic conductors with a TTF family such as TTF, TMTTF, TMTSF, HMTTF, and DBTTF. Among them, TMTTF and TMTSF give 2:1 single crystals and the latter affords the most conductive complex, showing a metallic characteristic down to 150 K. This can be observed by measuring the thermoelectric power and the ESR spectra. A crystal structure analysis indicates that only TMTSF molecules stack to form one-dimensional conduction pathways, while AzaTCNQ molecules are arranged side-by-side and oriented almost perpendicular to the donor molecules. There exists an orientational disorder of the nitrogen atom in the pyridine skeletone of an AzaTCNQ molecule, which may be associated with the weak temperature dependence of the electrical conductivity.
Basis Set Dependency of Energy Components in Hartree-Fock MO Theories. II. Conservability of Virial Ratio between Different Conformations
Authors: Ichikawa Hiroshi , Shigihara Atsushi
Published: July 2006

The authors examined 22 different basis sets in order to determine exactly how they reproduce the relative kinetic and potential energies. In an attempt to find the calculation error of such energy components, the virial relationship has been used between two conformations in which all bond lengths are optimized with respect to the total energy: i.e., the relationship, ΔV=−2ΔT, where ΔV and ΔT are the differences in the potential and kinetic energies. The degree of error was compared in terms of the relative virial error ((ΔE+ΔT)⁄ΔE) to the difference in the total energies (ΔE). STO-NG was found to give a large amount of casual error, up to 500% to ΔE. Such an error could be dramatically improved by using a split-valence method. It should be noted that 4-31G and 6-31G methods resulted in a small amount of error and that the inclusion of polarization functions does not always improve the amount of error.
The Entropy of Solution of Alkanes Measured by Gas-Liquid Chromatography and Interpreted by Means of Scaled Particle Theory
Authors: Fujiwara Hideaki , Ohtaku Ikuji , Takagi Tatsuya , Murata Saburo , Sasaki Yoshio
Published: July 2006

The entropy of solution was measured by gas-liquid chromatography for the alkanes from pentane to decane in dibutyl phthalate solution. The results are discussed in relation to the Wertz-type equation, which correlates the entropy of solution with the thermodynamic third-law entropy of the solute, and to the scaled particle theory. A scaled particle treatment assuming non-spheres(spherocylinders) is shown to give improved results and to be promising in reproducing the experimental values of the entropy of solution, whereas the same treatment of spheres failed to explain the trend in the experimental values.
Calorimetric and Dielectric Studies of Phase Transitions in Rubidium Nitrite
Authors: Moriya Keiichi , Matsuo Takasuke , Suga Hiroshi
Published: July 2006

The heat capacities of RbNO2 crystal have been measured between 15 and 330 K. Two phase transitions were found at (264.04±0.06) K and (83.8±0.2) K. The enthalpy and entropy of transition are (9310±450) J mol−1 and (35.9±1.8) JK−1 mol−1 for the former and (48±5) J mol−1 and (0.58±0.05) JK−1 mol−1 for the latter. The entropy of the high temperature transition was interpreted in terms of the orientational disorder of the NO2− ion. The dielectric constant increased from 6 to 10 as the transition temperature 264.04 K was traversed from below, indicating the increased motional freedom of the polar anion in the high temperature phase.
Role of Ti–O–Zr Bonding in TiO2–ZrO2 Catalyst for Dehydrogenation of Ethylbenzene
Authors: Hirashima Yutaka , Nishiwaki Katsuhiko , Miyakoshi Akihiko , Tsuiki Hideyasu , Ueno Akifumi , Nakabayashi Hirotoshi
Published: July 2006

A relationship between acid amounts over TiO2–ZrO2 catalysts and their activities for nonoxidative dehydrogenation of ethyl benzene to styrene was examined. The catalysts were prepared by two different methods; one is simultaneous hydrolysis of Ti and Zr mixed alkoxides solution and the other is physical mixing of pure TiO2 and ZrO2. The former consists of fine TiO2 and ZrO2 particles and is expected a lot of Ti–O–Zr bonding between the fine particles, while the latter is composed of large particles and less amounts of Ti–O–Zr bonding might be expected. Although the Ti–O–Zr bonding has been considered to generate a new acid site and to enhance the rate of dehydrogenation of ethylbenzene, the acid amounts and the rates observed on unit surface areas of both catalysts were not significantly different. On the basis of these results, the role of Ti–O–Zr bondig in TiO2–ZrO2 catalyst for dehydrogenation of ethylbenzene is discussed.