bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dielectric Relaxation and Molecular Structure. XI. Dielectric Behavior of Various Polar Molecules in the Supercooled o-Terphenyl Solution
Authors: Nakamura Masahiko , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
The dielectric constants and losses of dilute solutions of anthrone, xanthone, phenothiazine, 9-fluorenone, benzophenone, diphenylnitrosamine, 1,8-dinitronaphthalene, p-nitrotoluene and m-nitrophenol in o-terphenyl have been measured in the supercooled state in the frequency range 1–100 MHz and temperature range 15–30 °C. The results have been analyzed by Davidson-Cole’s skewed-arc method to calculate the relaxation times, the distribution parameters, the activation enthalpies and entropies for the dielectric relaxation processes.
Spectroscopic and Theoretical Studies on the Protonation to Xanthone Derivatives
Authors: Mizutani Kimiko , Miyazaki Kimiko , Ishigaki Kimiko , Hosoya Haruo 
Published: July 2006

Abstract
Ultraviolet absorption, fluorescence, and excitation spectra of xanthone and its hydroxyl and methoxyl derivatives were measured in sulfuric acid solutions of various acidities. The basicities (pKa’s) of these compounds were obtained from the spectral change. Variable-β type molecular orbital calculations of the π-systems were performed, assignment of the absorption spectra being made. It was confirmed that protonation occurs at the carbonyl oxygen atom. A method for obtaining the equilibrium constant without knowing the absolute intensity is proposed.
High-resolution Photoelectron Spectroscopy of Naphthacene Polycrystal by Means of Helium 21.22 eV Resonance Line
Authors: Seki Kazuhiko , Harada Yoshiya , Ohno Koichi , Inokuchi Hiroo 
Published: July 2006

Abstract
The photoelectron spectrum of naphthacene polycrystal was obtained with a high-resolution photoelectron spectrometer using a helium 21.22 eV light source, and the vibrational fine structures were examined. The resolution, 21 meV FWHM for the argon P3⁄2 peak, became much better than that obtained by means of a retardingpotential-type electron analyzer. Broad peaks with no distinct intramolecular vibrational structure were observed, and the origin of the peak width was discussed.
An MO Calculation of 1,3-Dipolar Cycloaddition between Ethylene and Diazomethane
Authors: Minato Tsutomu , Yamabe Shinichi , Inagaki Satoshi , Fujimoto Hiroshi , Fukui Kenichi 
Published: July 2006

Abstract
A semiempirical SCF MO calculation of the reaction between ethylene and diazomethane was carried out as an example of 1,3-dipolar cycloaddition. A calculation of the interaction energy and electron population by the use of the configuration interaction wave function showed that the formation of the two new bonds in this reaction is concerted but non-synchronous. This result is attributable to the extension of the highest occupied molecular orbital of diazomethane.
Magnetic Susceptibility of Magnesium 2,2′-Dipyridylide in its THF Adducts
Authors: Horiba Tatsuo , Hara Ken-ichi , Inoue Motomichi , Kubo Masaji 
Published: July 2006

Abstract
The magnetic susceptibility of magnesium 2,2′-dipyridylide has been determined in its THF (tetrahydrofuran) adducts in a temperature range of 1.6–20 K. The susceptibility of Mg(dipy)2.THF exhibits two maxima at about 3.9 and 9.5 K due to short range and long-range interactions, respectively. The observed susceptibility conforms to the alternating linear Heisenberg model above about 6 K. Mg(dipy)2·3THF shows no definite maximum of magnetic susceptibility. The magnetic behavior of these complexes different from that of Be(dipy)2 is attributable to the difference in the ionic character between Mg–N and Be–N bonds.
The Reduction of [Ru(Hedta)(H2O)] at the Mercury Electrode and Subsequent Reactions
Authors: Shimizu Kunio , Matsubara Tadashi , Satô Gen P 
Published: July 2006

Abstract
The reduction of [Ru(Hedta)(H2O)] at the mercury electrode and the subsequent chemical reactions in buffer solutions were investigated by AC and DC polarography and by large-scale electrolysis. Two polarographic steps were observed; the more positive step is discussed in this paper. The step was a diffusion-controlled, one-electron reduction of ruthenium(III) to ruthenium(II). For [H+]=(10−3–10−5) mol dm−3 the reduction was reversible, and it became less reversible if [H+]&lt;10−5 mol dm−3. Large-scale electrolysis in formate buffer solutions at the potential of the polarographic diffusion current plateau confirmed that the reduction is a one-electron process. In formate buffer, the reduced form of the complex is deactivated. Furthermore, in the presence of perchlorate ions the reduced form is reoxidized to the original form. The rate constant for the reoxidation reaction at 25.0 °C was k2=(1.38±0.26)×10−3 mol−1 dm3 s−1. The activation parameters for the reoxidation reaction were ΔH\eweq=(94.1±17.6)×103J mol−1 and ΔS\eweq=(19.0±6.3) J K−1 mol−1.
Diels-AIder Reactions of 5,5,5-Trichloro-3-penten-2-one and Related Compounds
Authors: Tsuboi Sadao , Ishiguro Yasuhiro , Takeda Akira 
Published: July 2006

Abstract
The Diels-AIder reaction of 5,5,5-trichloro-3-penten-2-one (1a) with cyclopentadiene afforded exo-2-acetyl-endo-3-trichloromethylbicyclo[2.2.1]hept-5-ene (2a) stereoselectively. The stereochemistry of the reactions of cyclopentadiene with several γ-chlorinated α,β-unsaturated ketones was examined. The endo-directive abilities decreased in the following order: CCl3&gt;CCl2CH3, CHCl2, CCl(CH3)2&gt;CH(CH3)2&gt;CH3. Compound 1a reacted with butadiene and furan to give 4-acetyl-5-trichloromethylcyclohexene (3) and 4-(2-furyl)-5,5,5-tri-chloropentan-2-one (7) respectively.
The Synthesis of 1,3-Thiazines by the Reaction of Non-isolable β-Imino(dithiocarboxylic) Acids with Aldehydes
Authors: Miyauchi Tetsuko , Kadokura Yutaka , Fukada Naoaki , Takeshima Tatsuo 
Published: July 2006

Abstract
1,3-Thiazines, (1)–(6), were synthesized, in yields ranging from 2.9 to 43%, by the reaction of aldehyde with the intermediate β-iminodithiocarboxylic acids which are formed by the reaction of ketones with carbon disulfide in the presence of ammonia.
The Oxyphenylation of Cyclic Olefins Conjugated to the Benzene Ring by Means of Palladium Chloride
Authors: Horino Hiroshi , Arai Mannosuke , Inoue Naoto 
Published: July 2006

Abstract
The reaction of 1,2-dihydronaphthalene, indene, and acenaphthylene with phenylpalladium chloride prepared in situ from phenylmercuric chloride and lithium chloropalladate in aqueous acetone afforded 2-phenyltetrarol, 2-phenylindanol, and 2-phenylacenaphthenol respectively, accompanying by the corresponding phenylated olefins. Acetoxyphenylation products were also obtained in the reactions in acetic acid. The configurations of these oxyphenylated compounds were determined to be trans.
Pyridoxal Model Compounds. I. The Regioselective Formylation of Methoxy-substituted Aromatic Compounds
Authors: Iwata Masaaki , Emoto Sakae 
Published: July 2006

Abstract
9-Substituted 2-methoxyanthracenes (IVa–d) and -triptycenes (Va, b), and 3-substituted anisoles (VIa, b) were formylated by the use of the Vilsmeier-Haack method (Method A) and the metallation method using n-butyllithium (Method B). By the Method A, IVa–c, Vs’, and VIs’ were regioselectively formylated at C-1, C-3, and C-6 respectively, without exception, while by the Method B IVa–c, Va, VIa, and VIb were regioselectively formylated at C-3, C-3, C-2, and C-6 respectively, and Vb gave C-1 and C-3 formylated derivatives in the ratio of 10 to 1 respectively. Possible transition states concerning the occurrence of the regioselectivity were proposed and discussed.
The One-electron Reduction of Carbonium Ions. VI. The Trapping of the Cycloheptatrienyl Radical with 2-Methyl-2-nitrosopropane in the Course of the Zinc Reduction of the Tropylium Ion
Authors: Okamoto Kunio , Komatsu Koichi 
Published: July 2006

Abstract
The zinc reduction of the tropylium ion was carried out in the presence of 2-methyl-2-nitrosopropane (a radical scavenger) in H2O–THF (7:3 by volume) at room temperature. In the reaction mixture with a short reaction time (5 min), t-butyl tropyl nitroxide (II) (a radical-trapping product) was identified by the ESR analysis. α-Phenyl-N-t-butylnitrone (I), which was isolated from the reaction mixture during a prolonged reaction time (30 min), was proved to be derived from the nitroxide II through the hydrogen abstraction by t-butyl nitroxide, which was itself formed from 2-methyl-2-nitrosopropane in situ in the acidic reaction mixture in the presence of zinc powder. The hydrogenation (on Pd/C) of the product mixture for a short reaction time (1 min) gave N-t-butyl-N-cycloheptylhydroxylamine and bicycloheptyl. On the basis of these observations, it is concluded that the primary product of the zinc reduction of the tropylium ion must be the tropyl radical.
Photoinduced Reactions. LXXVII. On the Applicability of Excited Acetone to Induce Photoaromatization of Dihydroheteroaromatics
Authors: Matsuura Teruo , Ito Yoshikatsu 
Published: July 2006

Abstract
Photoaromatization of various dihydroheteroaromatics and some carbocyclic dihydroaromatics with excited acetone was examined. Among the tested compounds, indoline, 2,3-dihydro-2-methylbenzofuran, and 9,10-dihydroanthracene were found to be photoaromatized. 2-Thiazolines, 2-oxazolines, 2-isoxazolines, 9,10-dihydrophenanthrene, 2,3-dihydro-5,6-dimethylpyrazine, 3,4-dihydro-1-methylisoquinoline, and 6-methyl-3(2H)-pyridazinone did not undergo photoaromatization, but recovered unchanged or underwent their own photochemical reactions.
Inositol Derivatives. 7. Azidolysis of Disulfonates of myo-Inositol and 1,2-O-CyclohexyIidene Derivative
Authors: Suami Tetsuo , Ogawa Seiichiro , Oki Shuichi , Sato Haruo 
Published: July 2006

Abstract
Reactions of azide ion with three disulfonates (1,4-, 1,5-, and 1,6-) of myo-inositol and its 1,2-O-cyclohexylidene derivative were studied. The structures of the new azido compounds thus obtained were established by PMR spectroscopy and reaction sequences. The reaction mechanisms of the neighboring-group participation reactions were discussed. Hydrogenation of the azido compounds followed by acetylation afforded the corresponding six inosadiamines as their hexaacetates: three known (allo-1,5, muco-1,3, and myo-4,5) and three hitherto unknown inosadiamines (allo-1,4, muco-1,2, and chiro-2,4).
A Base-induced Elimination Reaction of Phenylsulfonylacetates. I. General Aspect and Stereochemistry
Authors: Sera Akira , Mano Hiroshi , Maruyama Kazuhiro 
Published: July 2006

Abstract
Esters of phenylsulfonylacetic acid were found to undergo a base-induced β-elimination reaction with t-butoxide in t-butyl alcohol. The intervention of a carbanion as an intermediate of the elimination was proposed. The stereochemistry of the elimination was examined by the use of erythro and threo-2-deuterio-1,2-diphenylethyl phenylsulfonylacetates. From the deuterium content in a product, i.e., trans-stilhene, the elimination was found to occur predominantly in a syn fashion.
Spectral Intensities of Some Er3+ β-Diketonate Complexes
Authors: Isobe Toshiyuki , Misumi Seizo 
Published: July 2006

Abstract
The oscillator strengths of the absorption bands of Er3+ acetylacetonate, thenoyltrifluoroacetate, and dibenzoylmethide in methanol and dimethylformamide were determined and discussed in terms of the Judd-Ofelt’s theory. It was possible to use the Judd-Ofelt parameters for the evaluation of the spectral intensities. The oscillator strength of the hypersensitive transition 2H11⁄2←4I15⁄2 of Er3+ complexes, P(2H11⁄2), was indicated by the P(2H11⁄2)≈τcompνcomp U(2)/2J+1 and it is demonstrated that “hypersensitivity” may be explained only by the τ2 parameter of each complex, originating from the forced electric dipole transition.
Fluctuation of the Myoglobin Structure
Authors: Nakanishi Mamoru , Tsuboi Masamichi , Ikegami Akira 
Published: July 2006

Abstract
The kinetics of hydrogen-deuterium exchange in sperm whale metmyoglobin has been followed in aqueous solutions of various pD values (5.6–7.7) and at various temperatures (0–55 °C) by an infrared absorption measurement. At pD=5.6 and at 0 °C, 117 out of the total 148 peptide hydrogen atoms exchange relatively slowly with a rate of an apparent first-order reaction for one hour of the reaction time. This number (117) is almost equal to the sum of the number of peptide NH-groups (108∼111) which are found to be involved in hydrogen bonds with the carbonyls of other peptide groups and those (8) which are in hydrogen bonds with oxygen atoms of some sidechains in the myoglobin molecule in the crystalline state. At higher temperatures and/or at higher pD’s, however, only 109 peptide NH groups (assignable to those involved in the peptidepeptide hydrogen bonds) are found to exchange relatively slowly. The kinetics of the exchange reactions of these 109 peptide NH groups are explained by assuming that the fluctuation amplitude (i.e., the probability of finding the peptidepeptide hydrogen bonds broken) becomes lower on going from the terminus towards the inner portion in each of the eight α-helices involved in the myoglobin structure.
Molecular Structures of Hydrogen Cyanide and Acetonitrile as Studied by Gas Electron Diffraction
Authors: Karakida Ken-ichi , Fukuyama Tsutomu , Kuchitsu Kozo 
Published: July 2006

Abstract
The structures of HCN and CH3CN have been determined by gas electron diffraction for a critical comparison between diffraction and spectroscopic data. For HCN, the rg(C≡N), determined by gas electron diffraction, 1.158±0.003 Å, is consistent within the estimated limit of experimental error with that calculated from the spectroscopic re structure and the harmonic and anharmonic force constants by a perturbation procedure, 1.1588 Å. For CH3CN, electron diffraction intensities have been analyzed jointly with the rotational constants for the normal and three deuterated species determined by microwave spectroscopy by Kessler et al. and Thomas et al. The isotopic difference in the average C–H distance, δr=rav(C–H)–rav(C–D), has also been treated as one of the independent parameters. The analysis has led to the following structure: rg(C≡N)=1.159±0.002 Å, rg(C–C)=1.468±0.002Å, rg(C–H)=1.107±0.004 Å, ∠C–C–H (rav)=109.7±0.2° and δr=0.001±0.002 Å.
Total Synthesis of Natural Acetylenic Analogues of Isorenieratene and Renieratene
Authors: Ike Tetsuji , Inanaga Junji , Nakano Akio , Okukado Nobuhisa , Yamaguchi Masaru 
Published: July 2006

Abstract
The total synthesis of two natural acetylenic aromatic carotenoids, 7,8-didehydroisorenieratene (1) and 7,8-didehydrorenieratene (2), was carried out. Although the condensations involving C15-acetylenic ylids (derived from the phosphonium salts 7, and 8) as the intermediates gave only 9-cis isomers of 1 and 2, low-temperature condensations of C25-hexaene yield (derived from 19 and 28) with C15-acetylenic aldehyde (12a) led to all-trans 1 and 2, which were identical with natural specimens.
Viscosity B Coefficients for Some Homologous Series of Organic Electrolytes in Aqueons Solutions. The Effect of Ionic Groups
Authors: Tamaki Kunio , Ohara Y\={o}ko , Kurachi Hisashi , Akiyama Mitsuru , Odaki Hirokazu 
Published: July 2006

Abstract
The viscosity B coefficients for the three homologous series of sodium alkane carboxylates (acetate to butyrate), sodium n-alkyl sulfonates (methyl to hexyl), and n-alkylammonium chlorides (methyl to hexyl) in aqueous solutions at 25 °C have been determined. The B values increase linearly with the number of carbon atoms in the alkyl chains for each homologous series studied in this work, as well as for a homologous series of n-alkyl sulfate ions previously studied. In the case of the three kinds of organic anions with the same alkyl groups, the B values increase in the order: –COO−&gt;&gt;–SO3−&gt;–OSO3−. The ion-solvent interaction effect, as estimated by the combination of the B values with the molal volume at an infinite dilution for ions, is positive for each carboxylate ion; however, it is negative for the lower alkyl sulfonate, alkyl sulfate and alkylammonium ions. From these facts, –COO− may be classified as an “electrostrictive structure-maker,” whereas, –SO3−, –OSO3−, and –NH3+ are “electrostrictive structure-breakers.” In this connection, the reported specific interactions of these ionic parts with simple counter-ions on the activity coefficients of organic electrolytes, the counter-ion binding of polyelectrolytes, and the effect of counter-ions on the critical micelle concentrations of long-chain electrolytes are briefly discussed on the basis of the change in water structure induced by both cations and anions in water.
Synthetic Studies by the Use of Carbonates. I. The Nucleophilic Substitution Reaction of Ethylene Carbonate with Amine Hydrohalides
Authors: Yoshino Teruo , Inaba Shigeru , Komura Hajime , Ishido Yoshiharu 
Published: July 2006

Abstract
The reaction of ethylene carbonate with various amine hydrohalides gave the corresponding quaternary ammonium salts of β-hydroxyethylamines in good yields.
Codimerization of Ethylene and Styrene Catalyzed by Bis(triphenylphosphine)σ-Arylnickel(II) Halide–Trifluoroboron Etherate
Authors: Kawata Noboru , Maruya Ken-ichi , Mizoroki Tsutomu , Ozaki Atsumu 
Published: July 2006

Abstract
The codimerization of styrene with ethylene was studied using the catalyst system composed of bis(triphenylphosphine)σ-aryl(bromo)nickel(II) and trifluoroboron etherate in methylene dichloride. The codimerization takes place readily at 0 °C under atmospheric pressure to give 3-phenyl-1-butene selectively. The reaction scheme was discussed on the basis of the product distribution during the course of reaction and its kinetics.
Dehydration of Secondary Alcohols Catalyzed by Solid Acids
Authors: Yamaguchi Tsutomu , Tanabe Kozo 
Published: July 2006

Abstract
In order to examine the correlation between the acidic properties of catalysts and their activity or selectivity and to elucidate the reaction mechanism, dehydration reactions of 4-methyl-2-pentanol and 2-butanol over Al2O3, SiO2, SiO2–Al2O3, ZnS, NiSO4, Al2(SO4)3 or Al2O3 poisoned with basic compounds were carried out at 80–250°C by means of the conventional flow method or a thermal desorption method. The following results were obtained. 1) Both Brönsted and Lewis acids are active, the latter being so to a greater extent. 2) Even relatively weak acid catalysts of acid strength Ho=4.8–6.8 are active, the catalytic activity being correlated with the number of effective acid sites. 3) The selectivity of 4-methyl-1-pentene/4-methyl-2-pentene and 4-methyl-cis-2-pentene/4-methy-trans-2-pentene is lower for Brönsted acids than for Lewis acids and higher for weaker Lewis acid strengths. 4) The composition of butene isomers varies greatly with changes in desorption temperature and the amount of adsorbed 2-butanol in the case of Al2O3, but not much for SiO2–Al2O3. 5) The ratios of cis-2-butene/trans-2-butene and 1-butene/2-butene over Al2O3 are remarkably increased by poisoning with pyridine. A reaction mechanism including a new reaction path has been proposed.
Pressure Effect on the Absorption Spectra of Iron Compounds
Authors: Hara Yoji , Shirotani Ichimin , Sakai Nobuko , Nagakura Saburo , Minomura Shigeru 
Published: July 2006

Abstract
The effect of pressures up to 50 kbar has been measured on the absorption spectra in five ferric compounds, two ferrous compounds, and one mixed valence compound. In six compounds, but not in basic ferric acetate and soluble prussian blue, we observed pressure-induced bands which were assigned to the d-d transition of the converted Fe(II) for the ferric compounds and to the spin-forbidden d-d transition for the ferrous compounds. The absorption spectra for single crystals of potassium ferri- and ferrocyanide were studied at hydrostatic pressures up to 5 kbar. The band-peak intensity decreased with an increase in the pressure in both cases. The charge-transfer band from Fe(II) to Fe(III) of soluble prussian blue showed a blue shift (69 cm−1/kb) at hydrostatic pressures up to 7.2 kbar.
Polarized Absorption Spectra of the Hydroquinone and 1,4-Dimethoxybenzene Crystals in the Near and Vacuum Ultraviolet Regions
Authors: Kaya Koji , Fuke Kiyokazu , Nagakura Saburo 
Published: July 2006

Abstract
We measured the polarized absorption spectra of the γ-hydroquinone and 1,4-dimethoxybenzene crystals in the wave number region between 30000 cm−1 and 65000 cm−1. The dichroic ratios determined for the spectra of both crystals show that the bands at ∼290 nm and at ∼220 nm are polarized parallel with the short and long molecular axes, respectively; these support the assignment that they correspond to the Lb and La bands of benzene, respectively. The dichroic ratios and intensities determined for the bands in the vacuum ultraviolet region show that they do not simply correspond to the Ba,b bands of benzene and that mixing among appropriate excited states occurs in both crystals.
Organic Charge Transfer Salts. III. Photoconductive and Magnetic Properties of Organic Charge Transfer Salts
Authors: Tamamura Toshiaki , Yasuba Hiroshi , Okamoto Kenichi , Imai Tatsuro , Kusabayashi Shigekazu , Mikawa Hiroshi 
Published: July 2006

Abstract
The photoconductive and semiconductive properties of some organic charge-transfer (CT) salts consisting of a pyrylium or thiopyrylium cation and a polycyanoacid anion were investigated in single crystals. The salts are poor semiconductors with a resistivity of 1010–1012 ohm·cm at room temperature, but show relatively large photoconduction when irradiated with monochromatized light in the interionic CT absorption band. There is a strong possibility that the photocarrier is intrinsic in nature, being generated spontaneously from the excited CT state. A weak ESR signal observed originally in these salts increased on the CT band or near IR excitation. From the relationship between the darkcarriers, photocarriers, paramagnetic species and the excited CT state, a mechanism of electrical conduction is proposed in which the carrier generation by the CT interaction and the carrier migration by trapping conduction are involved.
Heterocyclic Azomethine Compounds and Their Reduction Products as Analytical Reagents. II. The Reaction of 1-Picolylideneamino-2-naphthol with Zinc(II)
Authors: Otomo Makoto , Fukui Kiyoshi , Kodama Kazunobu 
Published: July 2006

Abstract
The acid dissociation constants of 1-picolylideneamino-2-naphthol in aqueous dioxane media of various concentrations and the stability constant of the zinc(II) chelate in a 50 v/v% aqueous dioxane medium were determined potentiometrically at 25 °C and μ=0.1. The acid dissociation constants, pKa1, pKa2, and pKa3, at the zero dioxane mole fraction, evaluated by means of a least-squares treatment of the experimental data, are 3.16, 4.31, and 10.31 respectively. The overall stability constant of the zinc chelate was calculated be to logβ2=12.79. 1-Picolylideneamino-2-naphthol can be used as a sensitive reagent for the extractive spectrophotometric determination of zinc. The zinc chelate extracted into chloroform has an absorption maximum at 520 nm. The bathochromic shift is as large as 120 nm. The color system obeys Beer’s law over a concentration range up to 2×10−5M. The molar absorptivity is 4.5×104l/mol·cm at 520 nm.