bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Determination of Iron(II) after Separation by Collection of Its Ternary Complex of 1,10-Phenanthroline and Tetraphenylborate on Microcrystalline Naphthalene
Authors: Chang Lih-Fen , Satake Masatada , Puri B K , Bag Saswati P 
Published: July 2006

Abstract
A new procedure for the spectrophotometric determination of iron(II) after collection of its ternary complex with 1,10-phenanthroline and tetraphenylborate on microcrystalline naphthalene is described. In the presence of tetraphenylborate, the tris(1,10-phenanthroline)iron(II) ion is quantitatively collected on microcrystalline naphthalene as the ion-association complex. The system conforms to Beer’s law over the range 3–50 μg of iron in 10 ml of the solvent. The molar absorptivity was 1.2×104 l mol cm−1 at 514 nm. The effect of various factors, such as wavelength, pH, amounts of reagent and naphthalene, shaking time, and diverse ions, were also studied. The procedure method was satisfactorily applied to the determination of iron in standard aluminium alloy, aluminium, and magnesium metals.
The Synthesis of (+)-Pisiferol and (+)-Pisiferal
Authors: Matsumoto Takashi , Endo Yoshinori , Okimoto Masaru 
Published: July 2006

Abstract
Reduction of abieta-8,11,13,-trien-6-one with lithium aluminium hydride, followed by treatment with lead tetraacetate and iodine, affored 6β,20-epoxyabieta-8,11,13-triene. This was converted into a separable mixture of abieta-8,11,13-trien-20-ol (13) and 5βH-abieta-8,11,13-trien-20-ol (14) by a series of reactions; ether cleavage with acetic p-toluenesulfonic anhydride, catalytic hydrogenation, and reduction with lithium aluminium hydride. Acetylation of 13 and 14 gave the corresponding acetates, 20-acetoxyabieta-8,11,13-triene (11) and 20-acetoxy-5βH-abieta-8,11,13-triene (12). Friedel-Crafts acylation of 11 with acetyl chloride in the presence of anhydrous aluminium chloride afforded 20-acetoxy-12-acetylabieta-8,11,13-triene, which was converted into pisiferol by oxidation with m-chloroperbenzoic acid and subsequent treatment with lithium aluminium hydride. The synthetic pisiferol was oxidized with Jones reagent to give pisiferal. Similarly, 5βH-abieta-8,11,13-triene-12,20-diol was synthesized from 12. Conversion of the cis A/B ring junctions in 12 into the trans ones is also described.
Synthesis of 6- and 8-Phenyl-substituted Flavonoids
Authors: Matsumura Hisashi , Tsuchiya Toshio , Takeda Tsuneko , Imafuku Kimiaki 
Published: July 2006

Abstract
3-Acetylbiphenyl-4-ol and -2-ol were condensed with substituted benzaldehydes to give respectively 5′-and 3′-phenyl-substituted chalcones (1a–k), which were cyclized to afford 6- and 8-phenylflavanones. The chalcones (1a–k) also gave the corresponding 6- and 8-phenylflavones via dibromides. The effects of the phenyl group on the spectral data are also discussed.
Synthesis of 2-(1-Azulenyl)ethanamine Derivatives by Aminoethylation of Azulenes with Aziridines
Authors: Kurokawa Shinji , Anderson Arthur G 
Published: July 2006

Abstract
Azulene analogs of biological active amines were synthesized. Reaction of azulene or guaiazulene with 1-butanoylaziridine or with 1-butanoyl-2-methylaziridine in the presence of Lewis acid catalyst formed the corresponding N-butanoyl-1-(1-azulenyl)-, N-butanoyl-2-(1-azulenyl)-, and N-butanoyl-2-(1-guaiazulenyl) derivatives of ethanamine, or 1-propanamine, or of 2-propanamine, respectively (5–9). Reaction of guaiazulene with 2-methyl-, or 1,1-dimethylaziridinium, or with 1,1,2,2-tetramethylaziridinium ions gave the corresponding 1-(1-guaiazulenyl)- and 2-(1-guaiazulenyl) derivatives of ethanamine, or 1-propanamine, or of 2-propanamine. 2-(1-Azulenyl)- and 2-(4,6,8-trimethyl-1-azulenyl) derivatives of ethanamine were also obtained by the action of 1,1-diethylaziridinium ion on azulene or on 4,6,8-trimethylazulene. Compounds 5, 6, and 9 were active in vitro in the inhibition of prostaglandin 15-hydroxydehydrogenase and of cyclic AMP-phosphodiesterase.
Structure and Properties of Dichloro(l-proline)cadmium(II) Hydrate
Authors: Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio 
Published: July 2006

Abstract
An X-ray diffraction study of the title complex has been carried out. The crystal is orthorhombic, with the space group P212121; Z=4, a=10.021(3), b=13.562(4), c=7.298(3) Å. Block-diagonal least-squares refinements have led to the final R value of 0.035. The structure is very similar to that of dichloro(4-hydroxy-l-proline)cadmium(II), which has a one-dimensional polymer bridged by chlorine atoms and a carboxyl group like an infinite folding screen. The thermal behavior is, however, different from that of dichloro(4-hydroxy-l-proline)cadmium(II). The difference is likely to be due to a difference of the crystal structure, whether it contains intermolecular hydrogen bonds or not.
Reactions of Dialkylnickel(II) Complexes NiR2L2 with Alkyl (or Aryl) Halides, R′COY (Y=Cl, Br, OPh, OCOPh), and CS2
Authors: Yamamoto Takakazu , Kohara Teiji , Osakada Kohtaro , Yamamoto Akio 
Published: July 2006

Abstract
Reactions of Ni(CH3)2(bpy) (1), Ni(C2H5)2(bpy) (2) (bpy=2,2′-bipyridine), trans-Ni(CH3)2(triethylphosphine)2 (3), Ni(CH3)2(1,2-bis(diphenylphosphino)ethane) (4), and Ni(CH3)2(1,3-bis(diphenylphosphino)propane) (5) with alkyl or aryl halides, R′COY (Y=Cl, Br, OC6H5, OCOC6H5), and CS2 have been investigated. The reactions of NiR2L2 with alkyl or aryl halides are classified into three types of reactions by their reactirn products: Type A: NiR2L2+R′X→NiX(R′)L2+R–R, Type B: NiR2L2+R′X→alkane (RH)+ olefin (R′(–H)), and Type C: NiR2L2+R′X→NiR(X)L2+R–R′. Complexes 1 and 2 undergo mainly Type A reaction. Complex 3 gives Type A reaction product on treatment with C6H5Br, but it gives Type B reaction product on treatment with C2H5Br. On the other hand, 4 undergoes Type C reaction on interaction with C6H5Cl. The reactions with R′COY (Y=Cl, Br, OPh, OCOPh) are classified into two types of reactions by their reaction products: Type D: NiR2L2+R′COY→NiY(R′)L2+RCOR′ and Type E: NiR2L2+R′COY→NiY(R′)L2+RCOR. Complexes 1–3 undergo mainly Type D reaction, whereas complexes 4 and 5 mainly Type E reaction. The difference in the reaction route is discussed on the basis of presence or absence of vacant coordination site for attack by R′COY. The reaction of 4 with CS2 affords Ni(CS2)(1,2-bis(diphenylphosphino)ethane) with evolution of a reductive elimination product, ethane, whereas the reaction of 3 with CS2 gives a 1:1 adduct of 3 and CS2.
Nb2O5 Supported on TiO2. Catalytic Activity for Reduction of NO with NH3
Authors: Okazaki Susumu , Okuyama Tetsuhiro 
Published: July 2006

Abstract
Niobium(V) oxide supported on TiO2 showed a high catalytic activity for the reduction of NO with NH3 at temperatures higher than 450 °C. The presence of SO42− in Nb2O5 or in Nb2O5 supported on TiO2 brought about an increase in the catalytic activity.
Aromatic Nucleophilic Substitution. XVII. Formation and Decomposition of Anionic σ Complexes in Reactions of 2-Acetylaminoethyl 2,6-Dinitrophenyl Ether and N-Acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with Potassium t-Butoxide
Authors: Sekiguchi Shizen , Hoshino Ohtomo , Hirai Motohiko , Okada Keiji , Tomoto Noboru 
Published: July 2006

Abstract
Reactions of 2-acetylaminoethyl 2,6-dinitrophenyl ether and N-acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with t-butyl alcoholic KOC(CH3)3 in DMSO were followed by UV-VIS and NMR spectroscopies. In both reactions the same spiro anionic σ complex was formed.
Nucleophilic Substitution with Phosphide Anions Prepared by an Action of Sodium Dihydridobis(2-methoxyethanolato)aluminate on Phosphorus Compounds
Authors: Yamashita Mitsuji , Suzuki Nobuyoshi , Yamada Manabu , Soeda Yukio , Yamashita Hiroaki , Nakatani Kaname , Oshikawa Tatsuo , Inokawa Saburo 
Published: July 2006

Abstract
Phosphide anions, prepared by an action of sodium dihydridobis(2-methoxyethanolato)aluminate on derivatives of phosphine, phosphine oxide, or phosphorus esters, react with primary and secondary alkyl halides to produce phosphine derivatives having a newly formed phosphorus-carbon bond. The reactivity increases in the order of chloride&lt;bromide&lt;iodide and of secondary&lt;primary in alkyl halide. Reaction of phosphide anion is also feasible with p-toluenesulfonate. Reaction of an anion of diphenylphosphine oxide seems to proceed mainly as an SN2 type process.
The Corrosion Inhibition of SS 41 Steel by Shoyu Oil
Authors: Sekine Isao , Asazuma Masahiro 
Published: July 2006

Abstract
The addition of shoyu (soy sauce) oil to an NaCl solution for use as a corrosion inhibitor of SS 41 steel was investigated by measuring the corrosion weight loss, the polarization curve, the polarization resistance, and the impedance of the metal-solution interface. The value of the weight loss and the double-layer capacitance, Cdl, decreased as the shoyu oil was added to NaCl solutions of various concentrations. The value of the corrosion current density, Icorr, as calculated from the weight loss, the polarization curve, and the impedance measurement, decreased with an increase in the concentration of shoyu oil. An efficient inhibition of the corrosion of SS 41 steel was observed above an additive concentration of about 0.3%. Thus, the shoyu oil was found to be useful as a corrosion inhibitor of an economical and anti-pollution type. From the results of the IR analysis, the inhibition of the shoyu oil was considered to be caused by the adsorption of fatty acids, especially unsaturated fatty acids involved in the shoyu oil.
Circular Dichroism Spectra and Stereochemistry of Dicyanotetrakis-(diamine)-tetra-μ-hydroxo-tricobalt(III)(3+) Complexes
Authors: Kaki Satoshi , Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
the chiral tetra-μ-hydroxo-trinuclear complexes, cis-[Co(CN)2{(OH)2Co(NH3)4}2]3+ and cis-[Co(CN)2{(OH)2Co(diamine)2}2]3+ have been prepared and separated into their optical isomers and/or diastereomers by column chromatography (diamine: ethylenediamine, (R)-1,2-propanediamine, and (S,S)-1,2-cyclohexanediamine). The absolute configurations of isomers have been assigned on the basis of their CD and 13C NMR spectra and the characterization of mononuclear complex produced by decomposition of the trinuclear isomers of ethylenediamine ligands. It has been proved that the main CD contributions due to the two chiral Co(OH)4(CN)2 and Co(N)4(OH)2 centers are additive for the present systems.
Stereoselective Formation of Rotaxanes Composed of Polymethylenebridged Dinuclear Cobalt(III) Complexes and α- or β-Cyclodextrin
Authors: Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
[2]-[[(en)2Co{NH2(CH2)2S(CH2)nS(CH2)2NH2}Co(en)2]Cl6]-[α- or β-CDX]-rotaxanes were prepared with partial stereoselectivity and characterized from their absorption and 13C NMR spectra, molar conductance, and elemental analysis (CDX=cyclodextrin; n=8, 10, and 12). The rotaxanes always showed apparently ΔΔ-rich. CD spectra, the highest selectivity (16% ΔΔ-rich) being found in the case of n=10 and α-CDX. The results are related to the direct preparation of [2]-[ΔΔ-[(en)2Co{NH2(CH2)2S(CH2)nS(CH2)2NH2}Co(en)2]Cl6]-[α-CDX]-rotaxanes (n=8, 10, and 12) in relatively higher yields than the corresponding ΛΛ rotaxanes: 3.5% for n=8, 21% for n=10, and 28% for n=12. Inclusion complexes of a new type [Co(en)2{NH2(CH2)2S(CH2)nBr}]Cl3·2(α-CDX) were also isolated (n=10 and 12).
Enzymatic Oxygenation of Sulfides with Cytochrome P-450 from Rabbit Liver. Stereochemistry of Sulfoxide Formation
Authors: Takata Toshikazu , Yamazaki Mayumi , Fujimori Ken , Kim Yong Hae , Iyanagi Takashi , Oae Shigeru 
Published: July 2006

Abstract
Stereochemistry of enzymatic oxygenations of various diaryl, dialkyl and aryl alkyl sulfides to the corresponding sulfoxides with hepatic microsomes obtained from phenobarbital pretreated rabbit was investigated in comparison with those of nonenzymatic oxidations. Relative reactivity of the sulfides in the enzymatic oxygenation, based on the yields of the sulfoxides and the amount of oxygen absorption, depends upon the steric demand of the substituent in the oxygenation of 2-substituted thiochroman derivatives. However, such a trend was not observed in the enzymatic oxygenations of various acyclic sulfides. A substantial asymmetric induction on the sulfur atom was always observed (e.g., 54% e.e. for benzyl t-butyl sulfide). Formation of the sulfoxide with R-configuration predominated over that with S-configuration. The enzymatic oxygenation of all the unsymmetrical sulfides examined proceeded via the same steric course. Diastereomeric ratios of the sulfoxides formed in the enzymatic oxygenations of various racemic sulfides bearing alkyl substituents at α-position are markedly favoured more for the trans isomers than for the cis ones, while the ratio was nearly fifty-fifty in the nonenzymatic oxidations with both MCPBA and NaIO4. These results suggest that the enzymatic oxygenation takes place at the less hindered side of the sulfide. Both enzymatic and nonenzymatic oxidations of rigid six-membered cyclic sulfides, trans-thiadecalins and 4-(p-chlorophenyl)thiane, similarly occurred at the less hindered side to give mainly equatorial sulfoxides. The yields of the four stereoisomeric sulfoxides were nicely determined in the enzymatic oxygenation of racemic 2-methyl-2,3-dihydrobenzothiophene to elucidate the steric course of the oxygenation. Dependency of this microsomal oxygenation upon cytochrome P-450 enzyme was proved by several inhibition experiments and also by the identical stereochemical results of the oxygenation of a few selected sulfides to those with a reconstituted system with purified cytochrome P-450 and co-factors.
Reactions of NH Radicals. I. Photolysis of HN3 Vapor at 313 nm
Authors: Kodama Sukeya 
Published: July 2006

Abstract
Photolysis of HN3 vapor was studied at 313 nm as a function of HN3 and Xe pressures, light intensity, and temperature. The photolysis of hydrazoic acid labeled with 15N was also studied. The quantum yields of N2, H2, and NH4N3 as a product were 4.85, 0.494, and 0.842 at 30 °C and 6.7 kPa of HN3, respectively. The mechanism for the main reactions was postulated as follows: HN3+hν(313 nm)→N2+NH(a1Δ); NH(a1Δ)+HN3→2N2+2H (2); NH(a1Δ)+HN3→N3+NH2 (3); NH(a1Δ)+HN3→N2+N2H2* (4). The rate constant ratios of k3⁄k2=0.746 and k4⁄k2=1.23 were obtained at 30°C. (k3+k4)⁄k2 decrease drastically with rising temperature. Xe is effective for the collisional deactivation, NH(a1Δ)+Xe→NH(X3Σ−)+Xe (15), and k15⁄(k2+k3+k4)=0.187 was obtained at 30 °C.
Effects of Pressure on Dielectric Relaxation in Supercooled Triphenylchloromethane–o-Terphenyl Solution
Authors: Naoki Motosuke , Matsushita Manabu 
Published: July 2006

Abstract
Dielectric measurements have been made as a function of frequency, temperature, and pressure on a binary mixture of triphenylchloromethane and o-terphenyl in its supercooled liquid region. Since the distribution of relaxation time is independent of temperature and pressure in the present experimental range, the time-temperature-pressure superposition is accurately applied. The activation parameters such as the activation enthalpy at constant pressure, H*P, the activation enthalpy at constant volume, H*V, and the activation volume V* are obtained as a function of temperature and pressure. H*V is only half H*P unlike liquids and associated liquids such as alcohols. V* as well as the pressure coefficient of temperature at constant relaxation time τ, (∂T⁄∂T)τ, is similar in magnitude to that of polymer liquids and larger than that of associated liquids. These facts have revealed the contributions of inter- and intramolecular interactions to the molecular mobility in the supercooled liquid. (∂T⁄∂P)τ coincides with the pressure coefficient of the glass transition temperature, dTg/dP. This gives a statement that the glass transition temperature in simple normal liquids, as well as in polymer liquids, is an isorelaxation-time state.
Effect of Pressure on the Adsorption of 1-Octadecanol at Oil/Water Interfaces
Authors: Iyota Hidemi , Aratono Makoto , Yamanaka Michio , Motomura Kinsi , Matuura Ryohei 
Published: July 2006

Abstract
In order to investigate the effect of pressure on the adsorption at interfaces, the interfacial tension was measured as a function of pressure and composition for the systems of water and dilute solutions of 1-octadecanol in cyclohexane, benzene, and their equimolar mixture. The interfacial density of 1-octadecanol and the volume of interface formation were evaluated from the experimental data. Under atmospheric pressure, cyclohexane exhibits a significant adsorption of 1-octadecanol and a rapid decrease in the volume of interface formation, giving rise to the phase transition from the expanded to the condensed state in the adsorbed film, while benzene and equimolar mixture display only a small decrease in the thermodynamic quantities on the 1-octadecanol adsorption. Under high pressure, however, all the systems studied cause the phase transition. The effects of pressure and solvent on the phase transition of the adsorbed film were revealed on the basis of the thermodynamic quantities.
Crystal Structure of N-Benzyl-α-methoxycarbonylmethanimine N-Oxide
Authors: Inouye Yoshinobu 
Published: July 2006

Abstract
The geometry of N-benzyl-α-methoxycarbonylmethanimine N-oxide in the crystalline state was established to be Z by X-ray crystal analysis. The crystal was monoclinic, space group Pc, a=11.069(1), b=5.2335(7), c=8.620(1) Å, β=105.37(1)°, Z=2. The final R value was 0.037 for 1760 reflections.
The Substituent Effects in Thiophene Compounds. I. 1H NMR and IR Studies in Methyl (Substituted 2-Thiophenecarboxylate)s
Authors: Satonaka Hajime 
Published: July 2006

Abstract
The 1H NMR spectra and the IR carbonyl stretching frequencies of methyl (3-, 4-, and 5-substituted 2-thiophenecarboxylate)s have been reported. Good linear correlations between the chemical shifts of the ring protons in methyl (4- and 5-substituted 2-thiophenecarboxylate)s and those of the corresponding protons in substituted thiophenes were observed. The coupling constants in methyl (substituted 2-thiophenecarboxylate)s gave good correlations against the corresponding ones in substituted thiophenes. The IR carbonyl stretching frequencies in methyl (5-substituted 2-thiophenecarboxylate)s were correlated reasonably well with the chemical shifts of 5-protons in 2-substituted thiophenes. The coupling constants in methyl 2-thiophenecarboxylate series were found to vary linearly with the electronegativities of the substituents.
Decomposition of Hydrogen Bromide or Iodide by Gas Phase Electrolysis
Authors: Kondo Wakichi , Mizuta Susumu , Oosawa Yoshinao , Kumagai Toshiya , Fujii Kinjiro 
Published: July 2006

Abstract
Gas phase electrolysis of HBr or HI was studied by using a fuel-cell-type electrolyzer provided with graphite gas diffusion electrodes and liquid film electrolyte of H3PO4. Current efficiency 100% may be achieved at decomposition voltages of 0.73 V (at 100 mA cm−2 and 150 °C) for HBr and 0.28 V (at 100 mA cm−2 and 145 °C) for HI. Both bromine and iodine produced may smoothly be evolved out of the anode in the gas or liquid form without being dissolved into the electrolyte H3PO4, causing no trouble on the separation of products. This electrolytic method may be incorporated in the bromine or iodine cycles for thermochemical hydrogen production to constitute an effective hybrid system.
Laser Excitation Spectrum of the Ã2A′(004) ← \~{X}2A″(000) Band of HSO Radical
Authors: Satoh Masayoshi , Ohashi Nobukimi , Matsuoka Shin-ichi 
Published: July 2006

Abstract
The dye laser excitation spectrum of the Ã2A′(004)←\~{X}2A″(000) vibronic band of HSO was observed and analyzed in the frequency range from 17132 to 17182 cm−1. 414 spectral lines were assigned to an ordinary c-type transition and 21 lines to an axis-switching transition. The rotational constants of HSO in the Ã2A′(004) state were used to calculate the inertia defect of 0.518 u Å2 for this state. A relatively large dependence of the centrifugal distortion constant on the vibrational quantum number was also found.
The Location and Microenvironment of Dimerizing Cationic Dyes in Lipid Membranes as Studied by Means of Their Absorption Spectra
Authors: Handa Tetsurou , Ichihashi Chikako , Yamamoto Izumi , Nakagaki Masayuki 
Published: July 2006

Abstract
The absorption spectra of three cationic dyes, Methylene Blue (MB), 3,3′-dipropyl-2,2′-thiadicarbocyanine (diS-C3(5)), and 9-aminoacridine (9-AA), were measured in aqueous suspensions of a phospholipid membrane and a surfactant micelle. The dyes were intensely partitioned into the membrane phase and dimerized to exhibit a remarkably large reduction in absorbance. The increase in the amount of the membrane beyond the amount where all the dye molecules were dimerized in the membrane phase resulted in a gradual increase in the absorbance due to the increase in the available membrane volume and the dilution of dye in the membrane phase. The changes in the wave lengths of the absorption maxima of the dye monomers by the partitioning into membrane thus obtained were interpreted in terms of the effective polarities of the dye surroundings (microenvironments). It was found that the rather hydrophobic diS-C3(5) penetrates deeply into the membranes and the micelles and is located in considerably nonpolar microenvironments, while MB remains at the polar-surface regions of the membranes and the micelles. On the basis of these results, the structures of the micelles and membranes are discussed.
A Study of the Redistribution Reaction of Tetramethyltin with Dimethyltin Dichloride in Several Aprotic Solvents
Authors: Yamashita Yukihide , Saito Koji , Yoshino Akihiro , Takahashi Kensuke 
Published: July 2006

Abstract
The redistribution reaction of tetramethyltin with dimethyltin dichloride was studied in eight aprotic solvents by using the 1H NMR technique. The second-order rate constant of the reaction (In k2) is proportional to the dielectric constant of the solvent. There is a weak relation between the rate constants (In k2) and the values of 2J(Sn–H) of Me2SnCl2 in several solvents, which are considered to be related to the coordination ability of the solvents. The rate constants are also related to Kosower’s Z values of the solvents. The activation entropies of the reaction in four typical solvents have large negative values. This predicts that the reaction proceeds via a four-center transition state.
ESR Studies of Bunsen-type Methane-Air Flames. I. Effects of the Entrainment and Diffusion of Secondary Air on the Chemical Reactions in the Flame
Authors: Claesson Ola , Noda Shoji , Yoshida Hiroshi 
Published: July 2006

Abstract
H atoms in a Bunsen-type methane-air flame have been studied by observing their ESR signals at different flow rates of O2 and N2 in a synthetic secondary air. The optical emissions from excited CH, C2, and OH radicals in the same flame have been also studied. It has been found that an increased O2 flow rate produces changes in the intensity of the ESR and emission signals, and that it also increases the burning velocity in the inner-cone flame. An increased N2 flow rate, on the other hand, has almost no effect on the flame. The inner-cone of a Bunsen-type flame is, therefore, not a completely premixed flame; it is affected chemically by the secondary air.