bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal Structure of Binuclear Copper(II) Complex with 3-Ethyl-2-pyridone and Magnetism of Its Homologues
Authors: Nishida Yuzo , Kida Sigeo 
Published: July 2006

Abstract
The crystal structure of bis(N,N-dimethylformamide)tetrakis(3-ethyl-2-pyridonato)dicopper(II) was determined by X-ray diffraction method. Crystal data: Space group P21/n(monoclinic), a=9.906(1), b=13.494(3), c=14.029(2) Å, β=103.81(1)°. The crystal consists of centrosymmetric binuclear units in which two copper(II) ions are linked by four pyridonate anions similarly to copper(II) acetate monohydrate. The Cu–Cu distance is 2.55 Å. The cryomagnetic data revealed that −2J values are in the range 360–405 cm−1 for the series of complexes.
Sulfur-Extrusive Rearrangement of α-Acylthio Ester by Lithium Amide
Authors: Tsuzuki Kazuo , Akeyoshi Masaharu , Omura Satoshi 
Published: July 2006

Abstract
α-Acylthio esters readily undergo facile rearrangement to give β-keto esters on treatment with lithium amide at −78°C. Thiolactone 3, a key intermediate for thiolactonic antibiotics, was synthesized by utilizing the rearrangement.
Intramolecular [3++2] Cycloaddition of 2-Alkenyloxy-1-naphthaldehyde Oximes
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Teramura Kazuhiro 
Published: July 2006

Abstract
The thermal treatment of the mixture of 2-alkenyloxy-1-naphthaldehydes and hydroxylamine hydrochloride in ethanol gave intramolecular [3++2] cycload-ducts, 1,3a,4,11c-tetrahydro-3H-naphtho[1′,2′: 5,6]pyrano[4,3-c]isoxazole hydrochlorides.
Alteration of Reaction Course in Thermolysis of cis-Diethylbis(tertiary phosphine)palladium(II) from Reductive Elimination to β-Elimination Process Induced by Addition of Tertiary Phosphine Ligand
Authors: Ozawa Fumiyuki , Kurihara Kunihiko , Yamamoto Takakazu , Yamamoto Akio 
Published: July 2006

Abstract
Addition of tertiary phosphine to a solution containing cis-diethylbis(tertiary phosphine)palladium(II) alters thermolysis course of the complex from reductive elimination process liberating butane to β-hydrogen elimination process in which ethane and ethylene are released. Study with a deuterium-labeled ethyl complex indicates involvement of an internal metalation process.
Optical and Magnetic Properties of Alkali-(18-Crown-6)-TCNQ Salts
Authors: Nakayama Hideyuki , Ishii Kikujiro 
Published: July 2006

Abstract
Absorption spectra, ESR and static susceptibility were measured on TCNQ salts which incorporate Na+- or K+-(18-crown-6) as the cation unit. Results indicate that charge-transfer interaction between TCNQ anions is weak in the Na+ salt, whereas it is very strong in the K+ salt.
Delayed Fluorescence in Mixed Crystals Due to the Direct Resonance Interaction, as Revealed by Excitation Duration and Intensity Effects on the Decay Behavior
Authors: Taen Shoji , Gondo Yasuhiko 
Published: July 2006

Abstract
The decay of the temperature-independent delayed fluorescence observed in the mixed crystals of phenanthrene in the biphenyl host has been studied at 77 K. That triplet molecules are involved in the mechanism for the emission of temperature-independent delayed fluorescence has been shown by observing the intensities at the instances of the short-pulse excitations effected with different dark periods after the steady-state excitation. It has been found that both the excitation duration and the excitation light intensity affect the decay behavior of the temperature-independent delayed fluorescence. The decay after short-pulse excitation has been observed to be more rapid than the decay after prolonged excitation with the same intensity. When the excitation light intensity is increased with a fixed duration, the delayed fluorescence is observed to decay more rapidly. It is concluded that the decay behavior of the temperature-independent delayed fluorescence can be accounted for in terms of the direct-resonance-interaction mechanism.
Complete Magnetic Anisotropy Films for Perpendicular Recording Prepared by an Electroless Plating Method
Authors: Osaka Tetsuya , Koiwa Ichiro , Okabe Yutaka , Matsubara Hiroshi , Wada Akihide , Goto Fumio , Shiota Norio 
Published: July 2006

Abstract
A complete magnetic anisotropy film was formed by an electroless plating method for a high-density perpendicular recording medium. The Co alloy plating bath, using ammoniacal malonate–tartrate–succinate mixed complexing agents was studied mainly by varying three main metal ion factors in the bath: i.e., the concentrations of NiSO4, NH4ReO4, and MnSO4. The fine columnar structure of magnetic film in a cross section was confirmed by SEM observation. Three different kinds of eight-inch disks A, B, and C, were prepared under selected conditions with magnetic film thickness of 0.50, 0.25, and 0.20 μm respectively. The recording performance was evaluated with a Winchester ring head with a 0.33 μm gap length under various head-medium spacings. A perpendicular recording mode was confirmed, and the following recording densities were obtained: D50=54 and 58 kFRPI for disk A, and 57 and 63 kFRPI for disk B when using 0.20 and 0.15 μm practical usable spacing respectively, and D50=68 kFRPI for disk C when using the more advanced 0.12 μm spacing. It was suggested that the electroless cobalt alloy plating has a high potential as a process for producing perpendicular recording media.
Spectroscopic Behavior of the Alkali Salts of Noncyclic Polyethers: Evidence for Interaction between the End Groups
Authors: Hiratani Kazuhisa 
Published: July 2006

Abstract
The electronic and fluorescence spectra of the alkali salts of noncyclic polyethers exhibiting selective transport for the lithium ion were investigated. In the electronic spectra hypochromicity in CH2Cl2 dependent on the kind of alkali metal ions was observed, and the magnitude of the hypochromic effect decreased in the following order: Li+&gt;Na+&gt;K+&gt;Rb+&gt;Cs+. Using the polar solvents, EtOH and MeCN, instead of nonpolar CH2Cl2, the hypochromicity is small. Also, in the fluorescence spectra, the quenching phenomenon dependent on the kind of alkali metal ions appeared in the same sequence as the hypochromicity in the electronic spectra. It is suggested that these results, together with our previous results, support a stacking structure between the terminal aromatic rings of the lithium salt in a nonpolar solvent, which has been proposed from the inspection of the CPK model building.
Crystal and Molecular Structures of Fenethazine Hydrochloride and Its Cation Radical-Copper(II) Complex Salt
Authors: Obata Atsuo , Yoshimori Masahiro , Yamada Koh-ichi , Kawazura Hiroshi 
Published: July 2006

Abstract
The crystal structures of fenethazine hydrochloride hydrate (FTZ·HCl) and [FTZ H]2+·[CuCl4]2−(FTZ–Cu) were determined. FTZ·HCl crystallized in the monoclinic space group P21/a with a=8.686(1), b=31.660(2), c=6.140(1) Å, β=100.44(1)°, V=1660.5(3) Å3, and Z=4. FTZ–Cu crystallized in the triclinic space group P\bar1 with a=20.433(5), b=12.721(4), c=7.526(2) Å, α=91.31(3), β=94.56(3), γ=99.69(2)°, V=1920.9(1) Å3, and Z=4. The structures were solved using the heavy-atom method and were refined by the block-diagonal least-squares method. The final R values were determined to be 0.052 for FTZ·HCl and 0.050 for FTZ–Cu. The formation of a cation radical causes the phenothiazine ring of the FTZ molecule to be flattened; the dihedral angle between benzene rings is increased from 140.3° for FTZ·HCl to 174.7 or 167.5° for FTZ–Cu. The 2-aminoethyl chain holds a trans conformation in FTZ–Cu and a near gauche form in FTZ·HCl. In FTZ·HCl crystals, the FTZ molecules form a layer along a in which the molecules array the phenothiazine ring as faced with the ring in the neighboring layer. In FTZ–Cu, two FTZ molecules form a pair with a close overlap of the phenothiazine rings, directed approximately perpendicular to a. The CuCl42− is located so as to counterbalance both the positive charge of the ring and the protonated amino group of the side chain.
Calorimetric Determination of Thermodynamic Parameters for the Dissociations of Acids in Dipolar Aprotic Solvents
Authors: Izutsu Kosuke , Nakamura Toshio , Takizawa Katsumi , Takeda Akihiko 
Published: July 2006

Abstract
A calorimetric method has been investigated for the determination of the thermodynamic parameters of acid dissociations in dipolar aprotic solvents. For the dissociations of monoprotonated bases BH+ (B: aniline, pyridine, triethylamine, tributylamine, triethanolamine, 1,3-diphenylguanidine and 1,1,3,3-tetramethylguanidine) in N,N-dimethylformamide, dimethyl sulfoxide (DMSO), acetonitrile and propylene carbonate, the solutions of the bases were titrated with small volumes of a “strong acid,” trifluoromethanesulfonic acid. In each solvent, there was an approximately linear relation of unit slope between ΔH298° and ΔG298° showing that the difference in pKa between different BH+’s can mainly be attributed to the difference in the enthalpy term. As for the solvent effect on pKa, however, the entropy term seems to play an important role. A preliminary study has shown that the calorimetric method is also applicable to the dissociations of HX-type weak acids (benzoic and salicylic acids in DMSO, for example), if the dissociation equilibria are not complicated by such reactions as homoconj ugation.
Synthesis of DMSO–SbCl5(1 : 1) Complex and Its Oxidizing Action toward Alcohols
Authors: Yamamoto Jiro , Ito Satoshi , Tsuboi Takashi , Tsuboi Toshiaki , Tsukihara Kumiko 
Published: July 2006

Abstract
From an equimolar mixture of DMSO and SbCl5 in carbon tetrachloride, a DMSO–SbCl5(1 : 1) complex (1) was formed as a white precipitate in a quantitative yield. The structure of 1 was determined by X-ray crystallographic analysis. Butyraldehydes, para-substituted benzaldehydes and benzils were obtained by the oxidation of butylalcohols, para-substituted benzylalcohols and benzoins using 1 as an oxidizing agent.
Liquid Crystal Materials with Sulfur Atoms Incorporated in the Principal Structure III. Trans and Cis Isomers of New Liquid Crystal Material: 2-(p-Substituted phenyl)-5-alky 1-1,3-dithianes
Authors: Haramoto Yuichiro , Kamogawa Hiroyoshi 
Published: July 2006

Abstract
Trans and cis isomers of 2,5-disubstituted 1,3-dithianes were synthesized by the acid-catalyzed thioacetalization of p-substituted benzaldehydes and dithiols. The results of identifications of trans and cis isomers made by means of 13C-NMR chemical shifts indicate that the isomerism occurred at the 5 position in the 1,3-dithiane ring. Benzaldehydes with electrondonating p-substituents produced less cis isomers than that with the cyano group, which seems to indicate the establishment of an equilibrium in the formation reaction between trans and cis isomers. Several electro-optic properties of trans- and cis-2-(p-cyanophenyl)-5-alkyl-1,3-dithianes were determined by using them as a dopant of mixture of liquid crystals. Mixture added with trans isomers was superior to that added with cis isomers in several points.
Disproportionation of Cyclohexadienes Catalyzed by Metallic Nickel
Authors: Sakai Mutsuji , Kimura Toshiya , Nakaoka Toshiaki , Sakakibara Yasumasa , Uchino Norito 
Published: July 2006

Abstract
Cyclohexadienes, 1,3-cyclohexadiene (1) and 1,4-cyclohexadiene (2), disproportionated to benzene (3) and cyclohexene (4) in the presence of catalytic amounts of metallic nickel prepared from nickel halides and zinc powder in N,N-dimethyformamide (DMF) under nitrogen.
Syntheses of Four Stereoisomers of β-Methyllanthionine
Authors: Wakamiya Tateaki , Oda Yoshiaki , Fukase Koichi , Shiba Tetsuo 
Published: July 2006

Abstract
Four stereoisomers of β-methyllanthionine were synthesized by coupling of N-enzyloxycarbonyl-3-methyl-d-cysteine with β-chloroalanine. 1H NMR analysis and retention time in amino acid analysis were studied on these compounds.
Fluorescence of RbH and RbD Formed by Irradiating the Mixed Gases Rb+Eb and Rb+D2 with Laser Light
Authors: Katô Hajime , Toyosaka Yukiko , Suzuki Tomonari 
Published: July 2006

Abstract
When a mixture of 85Rb, 85Rb2, and D2 was irradiated by laser light at 5145 or 4880 Å, small visible particles appeared and the fluorescence spectra were observed. By analyzing these spectra, we determined the rotational constants Bv and the centrifugal distortion constants Dv and Hv for the X 1Σ+ and A 1Σ+ states of 85RbD. By considering the isotopic dependence of the Dunham coefficients, we determined various molecular constants of 85RbH whose values were in good agreement with the observed fluorescence spectra of 85RbH excited by laser lines at 4762, 4765, and 4880 Å. The process of RbH formation is discussed.
Reaction in the System N(CH3)4–ZrO2–P2O5–H2O. Preparation and Characterization of Framework Zirconium Phosphates (NH4)xH1−xZr2(PO4)3 and HZr2(PO4)3
Authors: Kijima Tsuyoshi , Yajima Yoshiyuki 
Published: July 2006

Abstract
The hydrothermal reaction in the system ZrO2–P2O5–H2O in the presence of tetramethylammonium ions was examined within the temperature range 160–350 °C. This reaction resulted in the formation of framework zirconium phosphates (NH4)xH1−xZr2(PO4)3·yH2O (0.6≤x≤1,y≤0.3) as well as some other phases, including two tetramethylammonium intercalates. The framework phases were rhombohedral with lattice constants of, e.g., a=8.669 and c=24.23 Å for x=1.0. These phases were deammonated at 400–640 °C and converted to the proton-exchanged form HZr2(PO4)3. The protons of this phase are easily exchanged by unhydrated Li+ and Na+ ions, but not by K+ and Cs+, owing to the sieving effect of the bottleneck in the (Zr2P3O12)−1 framework. The acid strength of the proton form is a little weaker than that of α-zirconium phosphate.
Catalysis by Transition Metal Carbides. VI. Hydrogenation of Carbon Monoxide over WC, W2C, and W Powder Catalysts
Authors: Kojima Isao , Miyazaki Eizo , Inoue Yasunobu , Yasumori Iwao 
Published: July 2006

Abstract
WC, W2C, and W were comparatively studied for CO hydrogenation to reveal the catalytic role of carbon alloyed with metals. The main products of the reaction were CH4, CO2, and H2O on these catalysts, but the kinetic data obtained for WC catalyst were different from those for W2C and W catalysts: i.e., the apparent activation energies for CO consumption and for CH4 formation on WC were found to be about three times larger than those on W2C or W. Furthermore, the catalytic activity of WC was about 20 times larger than that of W2C and W. It was suggested that the hydrogenation of CO on WC proceeds via direct hydrogenation of adsorbed CO forming a CHO adsorbed species as an intermediate, whereas on W2C and W catalysts, dissociation of CO occurs in the initial step, followed by further hydrogenation of adsorbed carbon to form CH4. X-ray photoelectron spectroscopic (XPS) studies on WC and W2C showed that the WC surface catalytically activated was almost free from graphite carbon and oxygen as poison, but W2C surface was largely covered with graphite carbon. These distinctive catalytic behavior differences between the carbide catalysts are discussed on the basis of the structure of the active surfaces.
Solvent Effects on Chemical Reactivities II. Aromatic Substitution Reactions
Authors: Ohmae Takayuki 
Published: July 2006

Abstract
The propagator method is applied to the study of solvent effects on reactivities of aromatic substitution reactions. We obtain the following set of results: (1) The influence of nonpolar solvent on electrophilic reactions is opposite to that on nucleophilic reactions; (2) the solvent which has the large dielectric constant weakens the directive power of a substituent group; (3) frontier orbitals control solvent effects on the chemical reactivities of aromatic substitution reactions.
In-Plane Vibrational Modes of Guanine from an ab Initio MO Calculation
Authors: Nishimura Yoshifumi , Tsuboi Masamichi , Kato Shigeki , Morokuma Keiji 
Published: July 2006

Abstract
Harmonic force constants, in-plane vibrational frequencies, and in-plane vibrational modes of guanine have been calculated by an ab initio MO method. The force constants were calculated by the use of an energy gradient method with STO-3G basis set, and then they were corrected into “4-31G force constants” by the scaling factors given by us previously for the case of uracil. The corrected set of force constants could reproduce the observed frequencies of guanine, guanine-7, 9-15N2, guanine-1,3,amino-15N3 (at positions 1, 3 and amino), guanine-8-d (at position 8), guanine-1,9, amino-d4 (at amino and iminos), and guanine-d5. The calculated vibrational modes could also account for the results of earlier experiments on infrared and Raman spectra of guanine residues in 5′-GMP and other nucleotides.
Catalytic Function of Cobalt(III) Complexes with N,N′-Disalicylideneethylenediamine on Oxygenation of t-Butylphenols
Authors: Aimoto Y\={u}ko , Kanda Wakako , Meguro Sadatoshi , Miyahara Y\={u}ji , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Catalytic oxygenation of t-butylphenols has been examined with the cobalt(III) complexes with N,N′-disalicylideneethylenediamine (H2salen), K[Co(salen)CO3], Na[Co(salen)(N3)2], K[Co(salen)(CN)2], [Co(salen)(py)2]PF6, and [Co(salen)(NH3)2]PF6. The CO3-complex showed a high catalytic activity while the other complexes a low or no catalytic activity. Based on electronic and ESR spectral investigations, it has been shown that the reaction is initiated by the direct oxidation of t-butylphenols by the CO3-complex through a phenolatocobalt(III) intermediate.
The Crystal Structure of [4R,7S]-7-Isopropyl-4-methyl-2-azepanone [(−)-Menthone Lactam]
Authors: Takayanagi Hiroaki , Hirose Etsuko , Furuhata Kimio , Ogura Haruo 
Published: July 2006

Abstract
The conformation of the title compound was determined by X-ray crystal analysis. The seven-membered lactam ring is in a quasi-chair conformation with the amide chromophore being approximately coplanar.
NMR Spectra of Benzenes Containing Trifluoromethyl Groups
Authors: Takahashi Kensuke , Yoshino Akihiro , Hosokawa Kenzo , Muramatsu Hiroshige 
Published: July 2006

Abstract
The 1H, 13C, and 19F NMR spectra of the nine title compounds were measured. The substituent effect of a trifluoromethyl group were generally additive for the 1H, 13C, and 19F chemical shifts. The assignment of the 13C signals was assisted by the observed coupling constants between the carbon and the fluorine, which were about 275, 35, and 6 Hz for the 1J, 2J, and 3J values of these compounds.
Synthesis of 1-Phenylsulfonylcyclopropanecarboxylic Acid Derivatives
Authors: Takahashi Masahiko , Suzuki Hideo , Kata Yoshimi 
Published: July 2006

Abstract
Ethyl phenylsulfonylacetate was treated with 1,2-dibromoethane in the presence of benzyltriethylammonium chloride and alkali to give 1-phenylsulfonylcyclopropanecarboxylic acid, from which the carbonyl chloride, ester, carboxamide, 1,2-diacylhydrazine, carbonyl azide, carbamate, isocyanate, and γ-butyrolactone derivatives were prepared.
A Practical Synthesis of N-Bromo Imides by Use of Sodium Bromite
Authors: Kajigaeshi Shoji , Nakagawa Takashi , Fujisaki Shizuo , Nishida Akiko 
Published: July 2006

Abstract
N-Bromo imides can be readily prepared under mild conditions by a reaction of imides with sodium bromite in the presence of hydrobromic acid in fairly good yields. The scope and limitation are also presented.
Valence Isomerization between Water-soluble Norbornadiene and Quadricyclane Derivative
Authors: Maruyama Kazuhiro , Tamiaki Hitoshi , Yanai Tetsuya 
Published: July 2006

Abstract
Photoisomerization of 3-(aryicarbamoyl)norbornadiene-2-carboxylic acid 1 to the corresponding quadricyclane derivative 2 in an aqueous alkaline solution was clean and dependent upon the p-substituent of the aryl group. The exothermically reversal reaction of 2 to 1 was also clean but independent upon the substituent.
Hydrogenation of Carbon Monoxide on CO Reducing Catalyst and Solid Acid (III). The Effect of the Pore Size and Acid Properties of Zeolite on the Product Distribution
Authors: Saima Hitoshi , Fujimoto Kaoru , Tominaga Hiro-o 
Published: July 2006

Abstract
Synthesis gas reactions over hybrid catalysts composed of Pd/SiO2 and zeolites and methanol conversion on the same zeolites were studied. The selectivities to aromatic hydrocarbons were about 30% for the methanol conversions over ZSM-5, de-aluminated mordenite, and de-aluminated Y type zeolite (DAY), which possess strong acid sites. When ZSM-5 or mordenites were combined with Pd/SiO2 and subjected to synthesis gas conversion, the selectivities to aromatic hydrocarbons were between 10% and 30%. However, the synthesis gas reaction over the hybrid catalyst composed of Pd/SiO2 and DAY, gave few aromatic hydrocarbons, but aliphatic paraffins with 2 to 6 carbon atoms. Over large pore zeolites like DAY, the diffusion of olefins is so quick that most of the olefins come out of pores to be hydrogenated to paraffins on the Pd/SiO2 catalyst. In contrast, because of the slow diffusion of olefins in the medium size pores of ZSM-5 or mordenite, olefins stay in the pores for long enough to form aromatic hydrocarbons on the strong acid sites before being hydrogenated.
The Conformations of (Z)-2,3,4,7,8,9-Hexahydrooxonin and (Z)-Cyclononene. X-Ray Structure Determinations of Isolaurallene and Neolaurallene, and Force–Field Calculations
Authors: Furusaki Akio , Katsuragi Shin-ichiro , Suehiro Katsunao , Matsumoto Takeshi 
Published: July 2006

Abstract
The molecular structures of isolaurallene and neolaurallene, diastereomeric nonterpenoids (C15H20O2Br2) from the red algae Laurencia, have been determined by X-ray crystallographic analysis. The crystal data are as follows: isolaurallene, orthorhombic, space group P212121, a=10.393(2), b=27.824(4), c=5.397(1) Å, Z=4, Dc=1.669 g cm−3; neolaurallene, monoclinic, space group P21, a=13.338(7), b=4.929(1), c=12.435(5) Å, β=98.22(4)°, Z=2, Dc=1.609 g cm−3. The structures were solved by the heavy-atom method, and refined by the block-diagonal least-squares method; the final R-values were 0.076 and 0.069 respectively. The (Z)-2,3,4,7,8,9-hexahydrooxonin rings in the two substances possess essentially the same conformation. The MM2 force–field calculations have shown that this conformation is almost identical to the most stable one of the 11 minimum-energy conformations found for (Z)-2,3,4,7,8,9-hexahydrooxonin. For comparison, the conformations of (Z)-cyclononene have also been examined by the force–field calculations. Of its 10 minimum-energy conformations obtained, the asymmetric one which Favini et al. already studied has the lowest energy.
The Spectrophotometric Determination of Phosphorus with o-Hydroxyhydroquinonephthalein and Iron(III)
Authors: Fujita Yoshikazu , Mori Itsuo , Kitano Shoko , Kawabe Hiroshi , Koshiyama Yozo 
Published: July 2006

Abstract
On this basis of the coloration formed with o-hydroxyhydroquinonephthalein, an anionic dye, and iron(III) in aqueous media, trace amounts of phosphorus(as orthophosphate ion) was determined. A sample solution containing posphorus and the reagent blank in an amber-colored test tube with a stopper were heated at 40 °C for 20 min in the presence of poly(oxyethylene)sorbitan monolaurate, a nonionic surfactant, as a dispersion agent. Beer’s law was obeyed over the range of ≈1 μg/10 cm3 of phosphorus, and the apparent molar absorptivity of the complex was 2.5×105 dm3 mol−1 cm−1 at 610 nm. The present method was applied to the determination of total phosphorus in water — a sample solution containing small amounts of metal ions —, and the recovery percentage was satisfactory, about 95%. Other compounds containing phosphorus such as 5′-adenosine triphosphate could also be determined without a preliminary treatment.