bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bromination and Mercuration of Bis-dimethlglyoximato(1-octenyl)-pyridinecobalt(III), 1-Octenyl Cobaloxime
Authors: Tada Masaru , Kubota Minoru , Shinozaki Hiraku 
Published: July 2006

Abstract
cis-1-Octenyl(pyridine)cobaloxime (I) and trans-1-octenyl(pyridine)cobaloxime (II) were prepared by the reaction of cobaloxime anion with cis-and trans-1-halooctene, respectively. Bromination of I and II in polar solvents gave preferentially cis trans-1-bromooctene. Bromination of I in carbon disulfide also gave preferentially trans-1-bromooctene, but bromination of II gave more cis-1-bromooctene. Mercuration of I and II with mercuric acetate in DMF gave preferentially 1-octenylmercury(II) compound with retention of configuration, but the mercuration in acetic acid gave ca. 1 : 2 mixture of cis and trans-1-octenylmercury(II) compound. Two mechanisms are proposed for these electrophilic displacement reactions; one involves the addition of electrophile as a first step, followed by the elimination of cobaloxime moiety, and the other involves the addition of bromonium or mercury(II) ion, followed by the elimination of cobaloxime moiety.
A Convenient Synthesis of Indolotropones and 6-Substituted 5-Azabenz[b]azulenes
Authors: Yamane Kameji , Fujimori Kunihide 
Published: July 2006

Abstract
Several substituted indolo[2,3-b]tropones were prepared by the dehydrobromination of 7,7-dibromo-7,8,9,10-tetrahydrocyclohept[b]indole-6(5H)-ones (2a–h), which had been obtained by the bromination of 7,8,9,10-tetrahydrocyclohept[b]indol-6(5H)-ones (1a–h) with phenvltrimethylammonium tribromide (PTAB). 6,7,8,9-Tetrahydrocyclohept[b]indole-10(5H)-one (5a) and 6,7,8,9-tetrahydro-5-methylcyclohept[b]indol-10(5H)-one (5b) were obtained by the oxidation of hexahydrocyclohept[b]indole (4a) and the 5-methyl derivative (4b) with dichlorodicyanobenzoquinone (DDQ). Indolo[3,2-b]tropones (6a and 6b) were derived from 5a and 5b respectively. The reactions of 6-chloro-5-azabenz[b]azulene (8) with nucleophilic reagents gave the corresponding substituted products (9a–j).
The Reaction of Anhydrochloralurethanes with Ketene Acetals
Authors: Akiyama Tetsuo , Urasato Nobuaki , Imagawa Takeshi , Kawanisi Mituyosi 
Published: July 2006

Abstract
The reaction of anhydrochloralurethanes (I) with ketene acetals (II) has been found to give novel carbamate derivatives (III) in quantitative yield. The intermediacy of a cyclic intermediate, an oxazine derivative (IV), was confirmed by spectroscopic methods, although several attempts to isolate IV have been unsuccessful. The mechanism for formation of IV is discussed.
The Electrochemical Fluorination of Trifluoromethyl-substituted Benzenes
Authors: Yonekura Michimasa , Nagase Shunji , Baba Hajime , Kodaira Kazuo , Abe Takashi 
Published: July 2006

Abstract
The electrochemical fluorination of benzenes containing one or two trifluoromethyl groups has been carried out. They afforded perfluorocyclohexane derivatives with the trifluoromethyl group in good yields. Chlorobenzenes containing a trifluoromethyl group yielded chlorinecontaining perfluorocyclohexane derivatives carrying the trifluoromethyl group. Trifluoromethylbenzonitriles gave perfluoro(dimethylcyclohexane)s, whereupon the nitrile group was converted into a trifluoromethyl group, thus releasing nitrogen trifluoride. The electrochemical fluorination of a trifluoromethylnaphthalene gave perfluoro(methyldecahydronaphthalene) only in a small yield.
Catalytic Reduction of Sulfoxide by Bromine-Hydrogen Bromide System
Authors: Aida Tetsuo , Akasaka Takeshi , Furukawa Naomichi , Oae Shigeru 
Published: July 2006

Abstract
A small amount of hydrogen halides or halogens was found to catalyze the decomposition of dimethyl sulfoxide (DMSO), affording dimethyl sulfide (DMS) and other oxidized products. Of the halides or halogens, either bromine or hydrogen bromide is the most effective. DMSO decomposes until it is completely consumed. This catalytic decomposition takes place with other sulfoxides such as diethyl or tetramethylene sulfoxide but sluggishly with alkyl aryl or diaryl sulfoxides. The reaction with bromine apparently proceeds via the initial α-bromination of DMSO to afford α-bromomethyl methyl sulfoxide which is oxidized by (Kornblum Reaction) to afford such products as formaldehyde, methanesulfonic acid, and hydrogen bromide. These consecutive reactions form a process of “Oxidation-Reduction Cycle” between bromine-hydrogen bromide and DMSO-DMS. The effects of salts and DMS on the rate of decomposition are discussed.
Backbone Rearrangements of 3α,4α-Epoxyshionane into Bacchar-12-en-3α-ol and D: B-Friedo-bacchar-5(10)-en-3α-ol
Authors: Yamada Shûzô , Yamada Sachiko , Tachibana Kazuo , Moriyama Yoshihiko , Tanahashi Yoshiaki , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Upon treatment with boron trifluoride etherate, 3α,4α-epoxyshionane (7) rearranged into bacchar-12-en-3α-ol (9) and D : B-friedo-bacchar-5(10)-en-3α-ol (10), and their structures have been determined. Revision of the structure for the latter product from previously reported D : C-friedo-bacchar-8-en-3α-ol (20) to 10 was described.
Oxidation of 4-Alkyl-1-hydroxyimino-2,4,6-tri-t-butyl-2,5-cyclohexadienes : Formation of 4-Alkyl-2,6-di-t-butylnitrobenzenes via Iminoxyl Radical
Authors: Inagaki Yoshio , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of 4-alkyl-1-hydroxyimino-2,4,6-tri-t-butyl-2,5-cyclohexadienes (1) with silver(I) oxide afforded 4-alkyl-2,6-di-t-butylnitrobenzenes (2) mainly, which were found to be formed via an iminoxyl radical on the base of the ESR spectra and by-products, 4-alkyl-1-t-butoxyimino-2,4,6-tri-t-butyl-2,5-cyclohexadienes (3). This reaction is a novel oxidative decomposition of iminoxyl radical and provides a practical preparative method for the nitrobenzenes (2). Oxidation of 1 with other reagents (nickel peroxide and m-chloroperbenzoic acid) and oxidation of 6-alkyl-1-hydroxyimino-2,4,6-tri-t-butyl-2,4-cyclohexadienes (5) have also been described.
Vapor-Phase Photolysis of cis-Cyclononene
Authors: Inoue Yoshihisa , Takamuku Setsuo , Sakurai Hiroshi 
Published: July 2006

Abstract
Direct and sensitized photolyses of cis-cyclononene (1c) vapor were investigated. The direct irradiation of 1c gave 1,8-nonadiene(2) and vinylcycloheptane via the thermally-activated ground state produced by rapid internal conversion from the excited singlet state initially generated. On the other hand, the sensitized photolysis of 1c gave 2 and five bicyclononanes, which are interpreted in terms of intramolecular hydrogen transfer reactions.
Syntheses of 3,4-Dimethylpyrrole
Authors: Ichimura Kunihiro , Ichikawa Susumu , Imamura Kazuo 
Published: July 2006

Abstract
Treatment of N-sulfinyl compound with 2,3-dimethylbutadiene gives a cycloadduct which affords 3,4-dimethylpyrrole in satisfactory yields by heating in a strongly alkaline methanolic solution.
A Synthesis of Methyl 2-Dimethylphosphoenolpyruvate by Dephosphorylation
Authors: Watanabe Kugako , (Kato) Ishimatsu Michiko , Tasaka Koa 
Published: July 2006

Abstract
Methyl 2-dimethylphosphoenolpyruvate was obtained by base-catalyzed dephosphorylation of methyl 2,3-bis(dimethylphospho)glycerate.
NMR Spectroscopic Studies on the Tautomerism in Schiff Bases of Tenuazonic Acid Analogs
Authors: Yamaguchi Tatsuaki , Saito Kimitoshi , Tsujimoto Toshio , Yuki Hidetaka 
Published: July 2006

Abstract
A NMR spectroscopic study of 15N-enriched Schiff bases of such tenuazonic acid analogs as 3-acetyltetramic acid, 3-acetyltetronic acid, and 3-acetylthiotetronic acid showed the predominance of ketamine forms in their tautomeric equilibria in CDCl3. The ratios of “external tautomers” between two different ketamine forms, as calculated from the 15N–H signal intensities, were compared favorably with the ratios obtained from the ring methylene signals.
Electronic Structure of Porphyrins. I. SCF-MO-CI Calculation Based on π-Electron Approximation
Authors: Tomono Kotaro , Nishimoto Kichisuke 
Published: July 2006

Abstract
The electronic structure and electronic spectra of metal free and metal porphyrins have been investigated by the MO method. In order to elucidate the effect of electron correlation on the electronic transitions, a new approximation for electron repulsion integral has been examined. For metal free porphyrin, the effect of hydrogen bondings on the electronic transitions has also been investigated. In metal porphyrin, the present calculation showed that almost two units of charges are transferred from the ligand porphyrin to the central metal ion through σ-type co-ordination bond. A satisfactory agreement between the calculated results and the experimental data was obtained when a new expression for electron repulsion integral, in which the effect of electron correlation is considered, was used. It was found that the Soret band of metal free porphyrin consists of almost degenerated Bx and By species.
X-Ray Photoelectron Spectra of Aryl-nickel Complexes
Authors: Sen\={o} Manabu , Tsuchiya Shinji , Hidai Masanobu , Uchida Yasuzo 
Published: July 2006

Abstract
The nature of bondings in aryl-nickel complexes has been clarified by means of X-ray photoelectron spectroscopy (XPS). Pi bonding between nickel and aryl ligand seem to be of little importance. Ni–Cl bondings are of partially ionic character. A correlation between stereochemical structure and satellites has been discussed. It is suggested that the aryl-nickel complexes examined have diamagnetic square-planar structures. Measurements of solid-state susceptibilities support this view.
An X-Ray Study of Non-stoichiometric Pr0.6Gd0.4O1.5+δ
Authors: Endo Kazuhiro , Yamauchi Shigeru , Fueki Kazuo , Mukaibo Takashi 
Published: July 2006

Abstract
Non-stoichiometric Pr0.6Gd0.4O1.5+δ (δ=0.000, 0.075, 0.120, and 0.157), with a bixbyite structure, was investigated by X-ray diffraction. The intensities of the superlattice lines were found to decrease with an increase in δ. The structure analysis has revealed that metal ions gradually move to the ideal positions of the fluorite structure with an increase in δ and that excess oxygen ions preferentially occupy the Z-sites.
ENDOR Studies of the Hindered Internal Rotation of Alkyl Groups in the 1,4-Dialkyl Naphthalene Radical Anions
Authors: Nemoto Fujito 
Published: July 2006

Abstract
The ENDOR spectra were measured for the anion radicals of 1,4-dimethylnaphthalene, 1,4-diethylnaphthalene, and 1,4-dipropylnaphthalene. The β-proton splittings of the alkyl groups were 3.30, 2.85, and 2.44 G at −80 °C for 1,4-dimethyl-, 1,4-diethyl-, and 1,4-dipropylnaphthalene respectively, and the positive temperature dependence of the β-proton splitting was demonstrated. Based on the Heller-McConnell relationship, a1,4β=(B0+B2cos2θ)ρ1.4π the β-proton splittings and their temperature dependence were interpreted in terms of a modified model of the restricted internal rotation of ethyl and propyl groups over two kinds of potential barriers. The rotational potential barriers thus estimated were 3.0 and 0.7 kcal/mol for the 1,4-diethylnaphthalene anion and 6.0 and 1.2 kcal/mol for the 1,4-dipropylnaphthalene anion. In the ENDOR spectra of potassium 1,4-diethylnaphthalene observed in THF solutions, two ENDOR lines attributed to the non-equivalent alkyl β-protons were observed at −110 °C, these lines collapsed to a single line when the temperature was raised to −70 °C. This phenomenon can be understood on the assumption that the steric effect of the solvated cation alters the rotational potential curve from a symmetric to an asymmetric one.
The Tribosorption of Hydrogen to Silicon Carbide
Authors: Ichioka Koji , Ito Tomoyasu , Shirakawa Toshiaki , Toi Keio , Tokuda Taneki 
Published: July 2006

Abstract
The tribosorption of hydrogen into granular silicon carbide was studied under shaking in the pressure range of 0.04–1 Torr at room temperature. The sorption was observed when the frequencies of the vibration were 10.0 and 13.3 Hz, but was not observed when they were 0 and 6.7 Hz. The rate of tribosorption evaluated from the change in the pressure of gas had its maximum value when the sample was shaken for 20–40 h. It was found that this tribosorption could be attributed to an absorption to the solid and could be treated as a diffusion process. The time dependence of the diffusion coefficient showed a behavior similar to that of the lattice defect. It is suggested that the chemical properties of hydrogen and the activation of the solid play important roles in the tribosorption process.
Magnetic Properties of [(H2O)2M{(OH)2Coen2}2](X)2·nH2O (M=Ni or Co, X=SO4 or S2O6 and n=5 or 7)
Authors: Kobayashi Hanako , Ohki Kazuo , Tsujikawa Ikuji , Osaki Keiji , Uryû Norikiyo 
Published: July 2006

Abstract
The magnetic properties of [(H2O)2Ni{(OH)2Coen2}2](SO4)2·7H2O, [(H2O)2Co{(OH)2Coen2}2](SO4)2·5H2O, [(H2O)2Co{(OH)2Coen2}2](SO4)2·7H2O, and [(H2O)2Co{(OH)2Coen2}2](S2O6)2·5H2O were investigated on powder samples. The paramagnetism of these compounds was considered to be that of the central Ni2+ or Co2+ion. From the fits of the experimental data with the calculated magnetic susceptibilities and the simulations of the ESR derivative curves, the ligand field parameters and g-values were determined. The ligand field around the Co2+ ion in [(H2O)2Co{(OH)2Coen2}2](SO4)2·5H2O was concluded to be tetragonal and in the other samples the ligand fields at the central divalent ions were found to be rhombic.
Degradation Spectra and the G-values for Ionization and Excitation of the Mixtures of Noble Gases
Authors: Okazaki Kiyoshi , Oku Eizo , Sato Shin 
Published: July 2006

Abstract
Degradation spectra of electrons and the W-values in the mixtures of He–Ne, He–Ar, Ne–Ar, and Ne–Kr irradiated by 100 keV electrons have been calculated by using the binary-encounter theory and the theory of the degradation spectrum. On the basis of these calculations, the Jesse effect, the negative Jesse effect, and the non-metastable Penning effect have been reconsidered. It was shown that at least a part of the negative Jesse effect and the non-metastable Penning effect are explicable as due to the degradation spectra of electrons.
Pulse Radiolysis of HgBr2 in Aqueous Solutions
Authors: Fujita Shin-ichi , Horii Hideo , Mori Toshiaki , Taniguchi Setsuo 
Published: July 2006

Abstract
Pulse radiolysis of aqueous HgBr2 solutions was investigated in the range from visible to 260 nm. HgBr2 is reduced by eaq−, H, CO2−, and some alcohol radicals except t-butyl alcohol radical to yield a transient species, HgBr, having an absorption spectrum with a maximum at 350 nm (ε350=(4.3±0.2)×103 M−1 cm−1) . k(eaq−+HgBr2) was determined by the pseud-first order decay of eaq− observed at 500 nm as (4.0±0.3)×1010 M−1 s−1. The reactivities of the other reducing species toward HgBr2 were estimated to be in the order eaq−&gt;CO2−&gt;\dotEtOH≈i-\dotPr-OH&gt;MeOH by comparing the absorption yields of HgBr in equimolar HgBr2 solutions containing the parent substances of the respective species. HgBr was found to decay following a second order rate law (2k=(1.0±0.1)×1010 M−1 s−1), producing Hg2Br2. HgBr2 reacts also with the OH radical to give a transient species which shows a similar spectrum to that of Br2−. It is considered that the transient may be HgBr3 instead of Br2−.
The Crystal Structure and the Absolute Configuration of (−)-Argemonine Methiodide
Authors: Kaneda Tsuguhiro , Sakabe Noriyoshi , Tanaka Jiro 
Published: July 2006

Abstract
The crystal structure of (−)-argemonine methiodide has been investigated by the X-ray method. The crystal system is orthorhombic, and the space group is P212121. The cell dimensions are a=13.443, b=20.838, and c=8.485Å. The structure parameters were refined by the block-diagonal least-squares method, and the final R-value was 0.055. The absolute configuration was determined by the MoKα anomalous scattering to be 1S5S, which is consistent with the CD result.
Indium(III) Complexes of Dl-Penicillamine in Aqueous Solution. Evidence for the Formation of Protonated and Hydrolyzed Complexes
Authors: Kojima Nakao , Sugiura Yukio , Tanaka Hisashi 
Published: July 2006

Abstract
The penicillamine–In(III) system has been investigated with potentiometric titration over a wide range of metal concentration at 21°C and I=0.1 (KNO3). In dilute concentration of metal (0.00025–0.0005 M) and ligand (free base), single species (InL and InL2) are predominantly formed. In higher concentration of metal (0.0025–0.005 M) and ligand (with an equimolar HCl), the protonated and hydrolyzed complexes (InLH, InL(LH), and InL(OH)) are also formed together with the simple species. The formation constants calculated with non-linear least-squares program were found to be: logβ110=15.330, logβ120=29.789, logβ11−1=18.858, logβ12−1=33.391, and logβ111=11.25 for InL, InL2, InLH, InL(LH), and InL(OH) species, respectively. The formation constants and ultraviolet spectra indicate that the proton in the protonated complex is attached to the amino-group of penicillamine.
The Structure of Ion-pairs of Λ- and Δ-[Co(en)3]3+ Ions with l-Tartrate and Related Anions as Deduced from Circular Dichroism Spectra
Authors: Fujita Miho , Yamatera Hideo 
Published: July 2006

Abstract
The circular dichroism (CD) spectra of optical antipodes of [Co(en)3]3+ and [Co(pn)3]3+ were measured in the presence of l-tartrate, l-tartranilate or related dicarboxylate ions. l-Tartrate(2−) ions gave a large and stereoselective effect on the CD spectra; the CD change was greater for the Λ-complex than for the Δ-complex. Hydrogen-l-tartrate(1−) and l-tartranilate(1−) ions also caused stereoselective CD changes. On the other hand, succinates-(2−) and l-malate(2−) ions gave small and non-stereoselective CD changes, and undissociated tartaric acid gave no CD change. From a comparison of the results, it was concluded that two hydroxyl and one carboxylate groups of the L-tartrate ion form hydrogen bonds with three N–H groups of the tris(diamine)cobalt(III) ion of the lel form.
Complexation between Copper(II) Ion and Large Excess Histidine in Aqueous Solution
Authors: Aiba Hiroji , Kuroda Yoshihiro , Tanaka Hisashi 
Published: July 2006

Abstract
The complexation between copper(II) ion and large excess histidine has been studied by visible absorption, proton and C-13 NMR spectral methods, in comparison with histamine–copper(II) system. The predominant species were considered to be ML2H+ and ML2H22+ at a=0 and ML2 at a=1 and 2, respectively from the spectral data in visible region, where a represents moles of base added per mole of diprotonated ligand. In ML2H+, one histidine is bound histamine-like with a carboxylate coordinated in apical position and the other glycine-like with a protonated imidazolium group, and in ML2H22+, both histidine molecules are bound glycine-like. Two histidine molecules are both tridentate with apical carboxylates in ML2. In histamine–copper(II) system, the coordination of the third histamine molecule in the apical position was suggested at a=1 and 2. The proton and the G-13 NMR spectra were reasonably interpreted in view of the above situation. A difference in the line-broadening of PMR signals was observed between histidine–copper(II) and histamine–copper(II) systems. This is mainly due to the difference in the exchange rates of the coordinated ligands of two systems.
Identification of Stereoisomers of Methyl Hexopyranosides by Mass Spectrometry of Their Trifluoroacetates
Authors: Ando Susumu , Ariga Toshio , Yamakawa Tamio 
Published: July 2006

Abstract
The mass spectra of the trifluoroacetates of methyl hexopyranosides and their partially deuterated derivatives were measured. The trifluoroacetyl derivatives were found to be very useful for identification of some stereoisomeric hexoses. The mass spectra were characterized by abundant peaks in the high mass range, the presence of a recognizable molecular ion, and sensitive spectral differences due to different stereoisomers. Glucose, galactose and mannose were distinguished from each other by comparing the intensities of the fragment ions due to the loss of trifluoroacetyl groups or cleavage of the pyranose ring. Alfa and β-anomers were distinguished by differences in the abundance of fragment ions produced by the loss of glycosidic methoxyl groups.
13C NMR Spectra of Some Methyl Cyclohexanecarboxylates
Authors: Senda Yasuhisa , Ishiyama Jun-ichi , Imaizumi Shin 
Published: July 2006

Abstract
13C NMR spectra of a series of stereoisomeric-substituted methyl cyclohexanecarboxylates have been obtained. The resonances for ring carbons of the isomers, in which both the methoxycarbonyl and the other groups have equatorial orientations, usually appear at a field lower than those of the isomers in which one of the two substituents has an axial orientation. No appreciable difference in shift due to the configurational change is observed in the resonances for the substituents. Observed chemical shifts are compared with predicted values.
Thermal Cis-to-Trans Isomerization of Substituted Azobenzenes II. Substituent and Solvent Effects
Authors: Nishimura Norio , Sueyoshi Toshinobu , Yamanaka Hideyuki , Imai Etsuko , Yamamoto Shunzo , Hasegawa Shigeo 
Published: July 2006

Abstract
The thermal cis-to-trans isomerization rate of various azobenzenes was followed by means of spectrophotometric and flash photolysis techniques. For para-donor/para′-acceptor-substituted azobenzenes such as 4-nitro-4′-dimethylaminoazobenzene, the rate was distinctly accelerated, the activation energy decreasing with the increase in the polarity of solvents. Introduction of substituents in para positions with respect to azo group increased the rate irrespective of substituent. The effect is additive and a Hammett-type equation holds. For 4-dimethylamino-and 4-nitroazobenzenes, while the 2-methyl group accelerated the rate, the 2′-methyl group did not. The results suggest that the isomerization proceeds via inversion mechanism and the rate is controlled mainly by the resonance stabilization in the coplanar transition state. The inversion center for asymmetric azobenzenes is discussed.
The Oxygen Gas Permselectivity of Dried Cellulose Acetate Membranes
Authors: Taniguchi Yoshio , Horigome Shinkichi 
Published: July 2006

Abstract
The oxygen gas permselectivity of annealed cellulose di- and triacetate membranes were investigated. We have suggested that the permeation ratios of oxygen to nitrogen gases of these membranes attain 7–8 by annealing in air at 180 °C.
The Synthesis of Single Crystals of HgX2·2HgS (X=Halogen)
Authors: Takei Kunio , Hagiwara Hitoshi 
Published: July 2006

Abstract
Single crystals of HgI2·2HgS (3×1.2×0.2 mm3), HgBr2·2HgS and HgCl2·2HgS were prepared by means of a high-temperature vapor-phase reaction. X-Ray experiments showed that the crystal of HgI2·2HgS, the unit cell of which has dimensions of a=9.36 Å, b=9.69 Å, and c=18.5 Å, belongs to the rhombic system.
Aromaticity of Monocyclic Ions
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
The infinitely-large annulenes with additional formal charges were employed as reference structures to evaluate the reference energies of monocyclic ions. On this basis, the Hiickel (4r+2) rule of aromaticity was verified within the framework of the HMO theory. The results obtained agree well with the available experimental evidence.
The Photoreduction of o-Methoxycarbonylbenzophenone
Authors: Tsujimoto Yuji , Shigemitsu Yasuo , Miyamoto Takuji , Odaira Yoshinobu 
Published: July 2006

Abstract
The photoreduction of o-methoxycarbonylbenzophenone (I) in a hydrogen-donating solvent, such as isopropyl alcohol and toluene, was shown to give diphthalidyl (II) or/and a coupling product (IV).