bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear Magnetic Resonance Study of Exchanging Systems. XI. 13C NMR Spectra of 9-Ethyltriptycene Derivatives and the Restricted Rotation of the Ethyl Group
Authors: Nakanishi Hiroshi , Yamamoto Osamu 
Published: July 2006

Abstract
9-Ethyl-1,4-dimethoxytriptycene, 1,5-dichloro-9-ethyltriptycene, and 9-ethyl-1,4-dimethyltriptycene were prepared. The 13C NMR spectra of these compounds were measured at low temperatures in order to obtain information about the restricted rotation of the ethyl group. It was found that the former two compounds have the meso isomer as well as the dl isomer. Different chemical shifts of the methylene carbons in the ethyl group, C(2) and C(3) of the benzene A ring, and some quaternary carbons in the two isomers of 9-ethyl-1,4-dimethoxytriptycene indicate that the 120°C rotation around Csp3–Csp3 single bond in the ethyl group deforms the benzene or bicyclo[2.2.2]octatriene skeleton. The complete line-shape analyses of the temperature-dependent 13C NMR spectra of this compound were performed, and the thermodynamic static parameters and activation parameters of the ethyl rotation were determined. The correlation between the rotational barriers of the alkyl groups and their bulkiness was briefly discussed.
The Synthesis of New Flavones with a 4H,10H-Benzo[1,2-b: 3,4-b′]dipyran-4,10-dione Skeleton and the Light Resistannce of These Compounds
Authors: Kaneta Makoto , Hikichi Hiroshi , Endo Seiichi , Sugiyama Noboru 
Published: July 2006

Abstract
Six analogous new flavones with a skeleton similar to arthraxin, which is a light-stable, natural, new flavone, have been synthesized by the use of a modification of Allan-Robinson’s flavone synthesis. The structures of these compounds were elucidated by means of the Gibbs reaction, NMR, and mass spectrometry. The light resistance of these flavones was then examined by means of UV spectrometry. The results indicate that these flavones, with a 4H, 10H-benzo[1,2-b : 3,4-b′] dipyran-4,10-dione skeleton, in contrast with natural common flavonol and arthraxin, show a high resistance to light.
The Effects of Solvents on the IR and PMR Spectra of Intramolecular OH…π and OH…O Hydrogen Bonded Systems
Authors: Ueji Shinichi 
Published: July 2006

Abstract
The effects of solvents on the intramolecular OH…π and OH…O hydrogen bonding in 2-arylphenols and 2,6-diarylphenols have been studied by examining the OH stretching IR absorption spectra in a range of solvents. The solvent shifts of the hydrogen bonded bands, νOH…π and νOH…O, followed the G correlation and the BHW plot. The success of both correlations suggests that the solvent shifts are primarily due to a specific solvent-solute association, even in relatively non-polar solvents. The solvent sensitivity of the OH…π and OH…O hydrogen bonded bands depended on the stereo-chemical environment around the hydrogen bonded system rather than on such electronic factors as the strength of the hydrogen bonding. On the basis of the relationship between the solvent sensitivity and the structural changes over a group of phenols, a simplified model for the solvent-solute association is put forward. Furthermore, this simplified model is also discussed in terms of the aromatic solvent-induced shifts in the PMR spectra.
The Reactions of 2-Arylacetylene-1-sulfonamides with Heterocumulenes
Authors: Hasegawa Kiyoshi , Hirooka Syuzi , Kawahara Hiroshi , Nakayama Akihiko , Ishikawa Keiichi , Takeda Nobuyuki , Mukai Hisakatsu 
Published: July 2006

Abstract
The syntheses of new heterocyclic compounds by the reaction of 2-arylacetylene-1-sulfonamides 1, (Z)-β-bromo- 12 or (Z)-α-chloro-β-styrenesulfonamides 13 with heterocumulenes are described. Weak base treatment of ureas R1C6H4C≡CSO2NHC(=O)NHR2 prepared from 1 and isocyanates gave 2-amino-6-aryl-1,4,3-oxathiazine 4,4-dioxides, whereas strong base treatment of the ureas afforded 3-oxo-4,5-diphenyl-2,3-dihydro-1,2,4-thiadiazine 1,1-dioxides where R2 is a phenyl group. The thiadiazines were also prepared by the strong base treatment of N-((Z)-α-bromo- or (Z)-β-chlorostyrylsulfonyl)-N′-phenylureas. The reaction of 1,12, or 13 with isothiocyanates in the presence of weak base gave 3-amino-5-aryl-1,4,2-dithiazine 1,1-dioxides, but the major products produced were 3-amino-5-benzylidene-1,4,2-dithiazole 1,1-dioxides when 12a was treated with isothiocyanates in the presence of strong base. The reaction of 1 with carbon disulfide and dimethyl sulfate in the presence of 5 M NaOH afforded 3-methylthio-5-benzylidene-1,4,2-dithiazole 1,1-dioxide with a small amount of 3-methylthio-5-aryl-1,4,2-dithiazine 1,1-dioxide. A mixture of both isomers was also prepared from 12a. Possible mechanisms for the formation of the heterocycles from 1, 12, or 13 are suggested.
The Hydrolysis of Carbohydrates in the Presence of a Reversed Micelle. II. The Hydrolysis of Sucrose in Benzene
Authors: Arai Kenichiro , Ogiwara Yoshitaka 
Published: July 2006

Abstract
The formation of a reversed micelle by dodecylbenzenesulfonic acid in benzene containing a certain amount of water was examined by means of the absorption spectra of the Methylene Blue added to the system. The hydrolysis of the sucrose secondary-solubilized in the system was then investigated. The maximum rate enhancement of 400-fold was obtained in the presence of the micelle on the basis of the reaction in an aqueous solution in the presence of hydrochloric acid, whereas the addition of ethanesulfonic acid to the system showed only a little effect on the reaction rate. The reaction rates were found to show behavior similar to that of the stability of the micelle with respect to changes in the substrate concentration and in the amount of solubilized water. From these results, the greater part of the rate enhancement obtained in the present system might be concluded to result from some effects due to the formation of the reversed micelle.
The Reactions of Olefins with Chloromethoxymethane or Dimethoxymethane in Nitriles
Authors: Wada Yasuo , Yamazaki Takeshi , Nishiura Kazuo , Tanimoto Shigeo , Okano Masaya 
Published: July 2006

Abstract
The Lewis acid-catalyzed reactions of olefins with chloromethoxymethane (CM) or dimethoxymethane (DM) and aliphatic or aromatic nitriles afforded the 1 : 1 : 1 adducts and/or their hydrolysis products in various yields, together with the 1 : 1 olefin–CM (or DM) adducts. AlCl3, FeCl3, ZnCl2, and SnCl4 were effective catalysts for the reaction with CM, whereas BF3 and SnCl4 were effective for that with DM. In the case of cyclohexene, the addition proceeded in the trans-manner; i.e., the methoxymethyl group and the nitrile molecule were added to the olefin from opposite sides.
Sensitized Photooxygenation of 9-Vinylphenanthrenes
Authors: Matsumoto Masakatsu , Dobashi Satoshi , Kondo Kiyosi 
Published: July 2006

Abstract
The sensitized photooxygenation of several 9-vinylphenanthrenes in carbon tetrachloride was investigated. In the cases of 9-vinyl- and 9-(β-substituted vinyl) phenanthrenes, the 1,4-cycloaddition of singlet oxygen to a conjugated system composed of the side chain and 9,10-double bond of the ring surpassed other oxidation modes, i.e., the “ene” reaction and 1,2-cycloaddition of singlet oxygen, to give the 1,2-dioxatriphenylene-type peroxides. On the other hand, the sensitized photooxygenation of 9-isopropenylphenanthrene gave a hydroperoxide due to the “ene” reaction.
New β-Carbonylvinylpalladium(II) Complexes Derived from 2-Chlorovinyl Ketones and Tetrakis(triphenylphosphine)palladium(0)
Authors: Onishi Masayoshi , Yamamoto Hideharu , Hiraki Katsuma 
Published: July 2006

Abstract
Chloro(trans-3-oxo-3-phenyl-1-propenyl)bis(triphenylphosphine)palladium(II), chloro (trans-3-oxo-3-p-tolyl-1-propenyl)bis(triphenylphosphine)palladium(II), chloro(3-oxo-1-cyclohexenyl)bis(triphenylphosphine)palladium(II), and chloro(5,5-dimethyl-3-oxo-1-cyclohexenyl)bis(triphenylphosphine)palladium(II) were prepared by reactions between Pd(PPh3)4 and linear or cyclic 2-chlorovinyl ketones. The halogen metathesis reactions with LiBr yielded the corresponding bromo complexes. Each of the β-carbonylvinyl groups in these eight complexes was found to be situated at the trans position to a palladium-halogen bond, on the basis of IR and 1H-NMR studies. The complexes with the cyclic β-carbonylvinyl groups were rather stable. The oxidative addition of linear 2-chlorovinyl ketones proceeded with retention of configuration about the double bond.
The Reactions of 2-Fluoro-1,3,5-trinitrobenzene (FTNB) as a New Condensing Reagent
Authors: Inomata Katsuhiko , Kinoshita Hideki , Fukuda Hirohiko , Tanabe Kumiko , Kotake Hiroshi 
Published: July 2006

Abstract
2-Fluoro-1,3,5-trinitrobenzene (FTNB) was found to be a useful new condensing reagent. Various amides, esters and thiocarboxylic S-esters were prepared in good yields from carboxylic acids with the reagent.
Asymmetric Reduction of Prochiral Ketones with Chiral Hydride Reagents Prepared from Lithium Aluminium Hydride and (S)-2-(N-Substituted aminomethyl)pyrrolidines
Authors: Asami Masatoshi , Ohno Hiroyasu , Kobayashi Susumu , Mukaiyama Teruaki 
Published: July 2006

Abstract
Asymmetric reduction of prochiral ketones with various hydride reagents prepared from lithium aluminium hydride and (S)-2-(N-substituted aminomethyl) pyrrolidines, derived easily by four steps from commercially available (S)-proline, yields optically active alcohols with 13–92% optical purity having the S-configuration.
Gas-chromatographic Studies of the Thermal Decompositions of Carbonato-pentaammine-, Carbonatotetraammine-, and Dicarbonato- diamminecobalt(III) Complexes in the Solid State
Authors: Onodera Sukeo 
Published: July 2006

Abstract
This paper will describe gas-chromatographic studies of the thermal decompositions of [CoOCO2(NH3)5]X·H2O (I), (CoCO3(NH3)4]X·nH2O (II), and K[Co(CO3)2(NH3)2(NH3)2]·H2O (III) (where, X=Cl, NO3, SO4, and n=0, 0.5, 3). The GEA curves for these compounds show that the complexes lose water between 80 and 160 °C, and that the decomposition of the anhydrous compounds begins with an evolution of ammonia at about 140 °C (for I) and 180 °C (for II and III).
Electrochemical Fluorination of Thiols
Authors: Baba Hajime , Kodaira Kazuo , Nagase Shunji , Abe Takashi 
Published: July 2006

Abstract
Electrochemical fluorination of C3 and C4 thiols has been investigated. Perfluoroalkylsulfur pentafluoride derivatives including new compounds, together with fragmented fluorocarbons and sulfur hexafluoride, have been formed.
Magnetic Circular Dichroism Spectra of Amino Acid Complexes of the [CoIII(N)5(O)]n+ Type
Authors: Ueda Etsuyo , Matsuoka Nobuko , Shimura Yoichi 
Published: July 2006

Abstract
MCD spectra of amino acid complexes of [Co(NH3)5(OCOCHRNH3)]3+, [Co(NH2CHRCO2)(NH3)4]2+, and [Co(NH2CHRCO2)(en)2]2+ types have been measured. The complexes belonging to a given type show nearly identical MCD curves irrespective of variation in their natural CD patterns. The complexes of d-, l-, and Dl-alanine show identical MCD spectra.
A Proton Magnetic Resonance Study of the Amide Configurations of 2-Acetoacetamido Derivatives of 4-Methylpyridine and Pyrimidine
Authors: Kondo Michio 
Published: July 2006

Abstract
It has been found by 1H NMR spectroscopy that 2-acetoacetamido-4-methylpyridine (1) and 2-acetoacetamidopyrimidine (2) exist predominantly in keto forms in CDCl3 and DMSO. The amide group of 1 seems to be in a s-trans configuration in both solvents, whereas that of 2 is in a s-cis form in CDCl3, but predominantly in a s-trans isomer in DMSO at room temperature. Configurations of the enol forms are discussed.
Application of Structure Construction Logic in CHEMICS for Determination of Amino Acid Sequence of Polypeptide by CI Mass Spectrometry
Authors: Yotsui Yasuhiko , Nomura Hisashi , Sano Mitsuji , Kudo Yoshihiro , Sasaki Shin-ichi 
Published: July 2006

Abstract
The amino acid composition for each ligopeptide fragment in the hydrolysis mixture of polypeptides was determined using mass spectrometer with a CI source. The amino acid sequence was elucidated by structure construction logic in CHEMICS.
Solvent Incorporation in Bromination of Acetylenes in Alcohols
Authors: Uemura Sakae , Okazaki Hajime , Okano Masaya , Sawada Seiji , Okada Atsuko , Kuwabara Kimiko 
Published: July 2006

Abstract
The reactions of acetylenes with bromine in alcohols at 20–25 °C afford dibromodialkoxyalkanes in good yields together with variable amounts of dibromoalkenes. Similar treatment of phenylacetylene with copper(II) bromide gives only bromophenylacetylene and 2-phenyl-1,1,2-tribromoethylene, the latter being formed by dibromination of the former with copper(II) bromide.
Conversion of Disilanes to Functional Monosilanes. IV. Synthesis of Methyldichlorosilane and Dimethylchlorosilane by the Reaction of Methylchlorodisilanes with Hydrogen Chloride in the Presence of Tetrakis(triphenylphosphine)palladium(0)
Authors: Matsumoto Hideyuki , Motegi Tsuneo , Hasegawa Minoru , Nagai Yoichiro 
Published: July 2006

Abstract
Methylchlorodisilanes such as 1,2-dimethyl-1,1,2,2-tetrachlorodisilane, 1,1,2-trimethyl-1,2,2-trichlorodisilane and 1,1,2,2-tetramethyl-1,2-dichlorodisilane were effectively cleaved by hydrogen chloride in the presence of tetrakis(triphenylphosphine)palladium(0) to give methylchlorohydrosilanes in good yields.
A Simple Synthetic Method for 2,15-Hexadecanedione from a Butadiene Telomer
Authors: Tsuji Jiro , Kaito Mitsumasa , Yamada Toshiro , Mandai Tadakatsu 
Published: July 2006

Abstract
The terminal double bond of 3,8-nonadienoate was oxidized to methyl ketone with a catalyst system of PdCl2/CuCl/O2 and the internal double bond was reduced to give 8-oxononanoate, which was hydrolyzed to 8-oxononanoic acid. The Kolbe electrolysis of the acid produced 2,15-hexadecanedione in a high yield.
A Molecular Orbital Study of the Electrophilicity of Hydroxyl Radical in Hydrogen Abstraction Reaction
Authors: Shinohara Hiroyuki , Imamura Akira , Masuda Takahiro , Kondo Masaharu 
Published: July 2006

Abstract
The electrophilicity of the hydroxyl radical in hydrogen abstraction from methane was studied by the CNDO/2 method. The stabilization energy due to the delocalization of the electrons (SEDE) between methane and the radical at a close distance was calculated. The electrophilicity defined by the SEDE from methane to the hydroxyl radical was larger than the nucleophilicity defined by that from the hydroxyl radical to methane. This result is consistent with the electrophilicity observed in hydrogen abstraction by the hydroxyl radical from a series of substituted methanes. For sulfhydryl radical, the electrophilicity was also suggested by the calculation for hydrogen abstraction from methane. The calculations were also carried out for various radicals which have low electron affinity (hydrogen atom and methyl radical), and the SEDE from methane to the radical was found to be large compared with that from the converse case.
The Mechanism of Oxygen Reduction at a LaNiO3 Electrode
Authors: Matsumoto Yasumichi , Yoneyama Hiroshi , Tamura Hideo 
Published: July 2006

Abstract
The reaction mechanism of the O2 reduction at LaNiO3 was studied by using a rotating ring-disc electrode, which consists of a LaNiO3 disc and Pt ring electrodes. It was found that the O2 was completely reduced to OH− on the Hoare path. Oxygen vacancies seem to be required in the oxide surface for reduction of adsorbed O2H− to OH−.
The Structure of Water in the Vicinity of Complex Ions of Transition Elements in Their Aqueous Solutions as Revealed by the Shift of the Temperature of Maximum Density of Water
Authors: Wada Goro , Nagao Emiko , Kawamura Nagako , Kinumoto Kyoko 
Published: July 2006

Abstract
The temperature of the maximum density (TMD) of aqueous solutions was measured for twenty complex ions of transition metals. From the degrees of depression of TMD, Despretz’s constant kionD and the constant of excess depression of mixing Δkion were determined. These constants along with Bion coefficient of viscosity give us information on the structure of water in the vicinity of ions. [Co(H2O)6]2+, [Ni(H2O)6]2+, [Cu(H2O)6]2+, and [Zn(H2O)6]2+ are electrostrictive structure-breakers in the natural order of Irving-Williams, Co(II)&lt;Ni(II)&lt;Cu(II)&gt;Zn(II). Of the complexes [Co(NH3)6]3+, [Co(en)3]3+, and [Co(pn)3]3+, the pn-complex is the strongest hydrophobic structure-maker due to the hydrophobic nature of its aliphatic constituent. Both [Fe(CN)6]3− and [Co(CN)6]3− are fairly strong electrostrictive structure-breakers, while [Fe(phen)3]2+, [Co(phen)3]2+, and [Co (phen)3]3+ are clathrate-like structure-makers. The EDTA and CyDTA complex ions of Co(II), Ni(II), Cu(II), and Zn(II) show no significant difference in kionD, the situation being complicated by the hydrophobicity of the ligands and the radius effect of the complex ion. The actions of ions as structure-makers should be classified into three categories; electrostrictive, hydrophobic (iceberg formation), and hydrophobic (clathrate-like structure formation). The characteristic influence of the structure-making nature on kionD, Δkion, and Bion is discussed.
Phase-shift Studies of Cadmium-photosensitized Luminescence of Ammonia and Some Aliphatic Amines
Authors: Umemoto Hironobu , Tsunashima Shigeru , Sato Shin 
Published: July 2006

Abstract
A phase-shift method was used to study the cadmium-photosensitized luminescence of ammonia and some aliphatic amines. The phase angles between the resonance fluorescence at 326.1 nm and the luminescence from the excited complexes have been measured at various modulation frequencies (10–99 kHz). The results could not be explained by means of the reaction mechanism proposed by analogy with the mercury-photosensitized luminescence of ammonia. In order to obtain a consistency, the equilibrium between the unstabilized and stabilized complexes: CdNH3†+NH3\ightleftarrowsCdNH3*+NH3, had to be taken into account. The reverse reaction was not necessary to explain the results of the mercury-photosensitized luminescence of ammonia. This discrepancy may be ascribed to the difference in the energy gap between the 3P1 and 3P0 states of mercury and cadmium.
Direct Measurement of the Interaction Energy between Solids and Gases. III. Comparison of the Calorimetric Titration Method with the Amine Titration Method for the Determination of Acid Strength Distribution of Silica-Alumina Surface
Authors: Taniguchi Hitofumi , Masuda Tatsuo , Tsutsumi Kazuo , Takahashi Hiroshi 
Published: July 2006

Abstract
The acid strength distribution of silica–alumina catalyst (alumina content 13 wt%) evacuated at 400 °C for 5 h was determined by the measurement of heat of adsorption of ammonia, and compared with that determined by amine titration by use of a series of Hammett indicators. The heats of adsorption of ammonia on silica–alumina poisoned with Hammett indicators were also measured in order to obtain the relation between the dissociation constant of the acid (pKa) and the heat of adsorption. When the dissociation constants of acid were equal to −5.6 and +3.3, the differential heats of adsorption of ammonia were observed to be 76.1 and 55.1 kJ/mol, respectively. The number of acid sites calculated from the heat vs. adsorbed amount curve was found to be about twice as large as that determined by amine titration. The discrepancy is discussed.
The Crystal Structure of l-Asparaginato-d-aspartatocobalt(III) Monohydrate
Authors: Sekizaki Masao 
Published: July 2006

Abstract
The crystal structure of l-asparaginato-d-aspartatocobalt(III) monohydrate, [Co(H2NCOCH2CHNH2COO)(OCOCH2CHNH2COO)]·H2O, has been determined by an X-ray diffraction method and refined by a block-diagonal least-squares method to give R=0.033 for 1517 non-zero reflections. The crystals are orthorhombic with the space group P212121, a=11.790(2), b=17.059(2), c=5.830(2) Å, and Z=4. The complex molecule has a slightly distorted octahedral coordination with fac(N) geometry. The amide group of l-asparaginate ion is coordinated through the nitrogen atom, and an enolic system of Co←NH=C(OH)–CH2– is formed. The complex molecules are held together through hydrogen bonds which form two-dimensional networks parallel to the (010) plane. The networks are piled up through hydrogen bonds by water molecules to complete three-dimensional networks.
Chemical Shifts of Sulfur KLL Auger Electron Energies in Its Compounds
Authors: Nishikida Shunichi , Ikeda Shigero 
Published: July 2006

Abstract
The sulfur 1s and 2p photoelectron spectra and KL23L23 Auger electron spectra in various sulfur compounds involving solid sulfur were measured by means of irradiation by Al Kα and Cr Kα X-rays. The chemical shifts of the S1s and S2p photoelectron spectra for compounds referred to the data for solid sulfur differ from each other in magnitude, but all are larger than that for the Auger electron spectra in the corresponding compound. The shift of the Auger electron spectra is different in fashion from those of the photoelectron spectra; the difference is largely attributable to the differences in relaxation energies. The extra-atomic relaxation energies due to core-electron emission were estimated by combining the atomic spectral data and the XPS and AES data of compounds; they were found not necessarily to depend upon the atomic charges. From the calculated sulfur Kα X-ray spectra corresponding to the difference in the binding energy between 1s and 2p, the number of electrons on each sulfur atom was obtained by using the method derived from Coulson et al., while the isolation was attempted on the basis of the contribution of polarization energies due to surrounding atoms to the extra-atomic relaxation energies.
Optical Activation of 2-Phenylpropionaldehyde via Some 2-Substituted Pyrrolidine Enamines
Authors: Matsushita Hajime , Tsujino Yasuko , Noguchi Masao , Saburi Masahiko , Yoshikawa Sadao 
Published: July 2006

Abstract
Optical activation of 2-phenylpropionaldehyde (PPA) via enamines using l-proline derivatives as amine components was studied. S(+)-PPA was obtained when R(−)-2-methylpyrrolidine and S(−)-2-ethoxycarbonylpyrrolidine were used, while R(−)-PPA was obtained when S(−)-prolinamide, N-(l-prolyl)pyrrolidine, N-(l-prolyl)piperidine, S(+)-2-(1-pyrrolidinylmethyl)pyrrolidine, and S(+)-2-(piperidinomethyl)pyrrolidine were used. This suggests that there are two mechanisms for optical activation.
Preparation and Reactivities of Phenylethynyl[1,1,1-tris(diphenylphosphinomethyl)ethane]copper(I) Complex
Authors: Hiraki Katsuma , Fuchita Yoshio , Morita Yasushi 
Published: July 2006

Abstract
Phenylethynyl[1,1,1-tris(diphenylphosphinomethyl)ethane]copper(I), [Cu(C≡CPh)(tdpme)]tdpme=1,1,1-tris(diphenylphosphinomethyl)ethane, has been prepared in good yield by a reaction between phenylethynyl-copper(I), [{Cu(C≡CPh)}n], and tdpme. From physicochemical and spectroscopic studies the complex is considered to have a monomeric tetrahedral structure. It reacts with p-cresol to give [Cu(O–C6H4–CH3-P)(tdpme)] and also with highly active hydrogen compounds, methyl cyanoacetate and methyl nitroacetate, to give [Cu{CH(CN)CO2CH3}(tdpme)] and [Cu{CH(NO2)CO2CH3}(tdpme)], respectively. However, moderately active hydrogen compounds, such as acetonitrile, dimethyl malonate, and nitromethane, do not react with [Cu(C≡CPh)(tdpme)]. The reactivities of the complex with active hydrogen compounds are discussed in correlation with the pKa values of the latter compounds.