bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyridoxal Catalysis in the α,β-Elimination of S-(p-Substituted phenyl)cysteines
Authors: Murakami Yukito , Kondo Hiroki 
Published: July 2006

Abstract
The pyridoxal-catalyzed α,β-elimination of S-(p-substituted phenyl)cysteines was studied at 50°C and μ=0.10 (KNO3) in 79% (v/v) aqueous acetonitrile in the presence of organic bases of different strength. The rate increased with an increase in basicity. The kinetic solvent isotope effect (kH2O⁄kD2O) of 1.15 is consistent with the reaction mechanism in which the α-proton abstraction occurs by the direct attack of a base on the proton. The elimination rate was insensitive to a change in the electronic nature of a leaving thiophenol, indicating that the α-proton abstraction can be referred to the rate-determining step. The rate showed a considerable dependence on the water content, as reflected on the activation parameters for reactions in 79% (v/v) aqueous acetonitrile as well as in water. The larger destabilization due to water-solvation at the transition state in the aqueous reaction system seems to cause a lower reactivity relative to the organic solvent system. The catalysis of benzene analogs demonstrated that the hydroxyl group adjacent to the aldehyde in pyridoxal plays a major role in the nonenzymatic α,β-elimination reactions.
The Preparation of Aryl Heptafluoroisopropyl Ketones from Aroyl Chlorides and Hexafluoropropene in the Presence of Fluoride Ions
Authors: Ishikawa Nobuo , Shin-ya Seiji 
Published: July 2006

Abstract
Aroyl chlorides and hexafluoropropene in the KF/DMF system gave aryl heptafluoroisopropyl ketones. The substituent effect on the yield was discussed.
The Chemistry of Americium. III. The Coprecipitation of Am(III), Am(V), and Am(VI) by Some Fluorides and Phosphates
Authors: Hara Mitsuo , Suzuki Shin 
Published: July 2006

Abstract
The radiochemical behavior of americium in the coprecipitation process involving a precipitate such as lanthanum, thorium, and ceric fluorides, zirconium, and bismuth phosphates was investigated at the tracer concentrations of americium. All the precipitates except zirconium phosphate completely carried the Am(III), leaving the Am(VI) in the supernatant. The lanthanum and thorium fluorides carried portions of the Am(V) in proportion to the amounts of the metal ion of the carrier added under any given conditions. Then, the analytical conditions were established for determining the distributions of the oxidation states of americium.
The Complexing of the Lithium Ion in Acetonitrile with Other Solvents. Investigation by the Use of a Cation-sensitive Glass Electrode
Authors: Nakamura Toshio 
Published: July 2006

Abstract
The complexing of the lithium ion with other popular solvents has been studied in acetonitrile (AN) using a monovalent cation-sensitive glass electrode. A method similar to that developed to study the complexing of the sodium ion was employed. Mono- and di-solvated species were formed for methanol, pyridine, formamide, methylfomamide, and HMPA. Tri-solvated species were also formed for DMF, DMA, and DMSO. In general, the complexing of the lithium ion with these solvents was more pronounced than that of the sodium ion. The formation constants for the mono-solvated lithium ion were 4.5 for methanol, 5.2 for pyridine, 16 for DMF, 20 for formamide, 25 for methylformamide, 49 for DMSO, 62 for DMA, and 2.1×103 for HMPA. When water was the complexing solvent, the equilibrium potential could not be obtained, probably because of the hydrolysis of the hydrated lithium ion. Prior to these experiments, the cation-sensitive glass electrode was confirmed to respond to the lithium-ion activity in different solvents by comparing its behavior with that of a lithium-amalgam electrode.
Viscosity Behavior of Coacervates of Magnesium and Calcium Highpolyphosphates
Authors: Umegaki Takao , Kanazawa Takafumi 
Published: July 2006

Abstract
The viscosities of magnesium and calcium highpolyphosphate coacervates were measured in the temperature range of 20 to 90 °C. The Andrade’s Equation was an approximate representation for the temperature dependence of viscosities of the coacervates. The activation energies of flow for the highpolyphosphate coacervates of magnesium and calcium were calculated to be about 7 kcal/mol and about 15 kcal/mol, respectively. The extension of the phosphate chains in coacervates was considered to be restricted, and the spinnability of the coacervates was probably originated, not by an elastic network structure, but by high viscosity of the coacervates. The viscosities of the magnesium coacervates decreased with an increase in water content and no remarkable effect of ethyl alcohol on the preparation of the coacervates was found.
Photo-addition Reaction of 1,4-Naphthoquinone with Olefins. Formation of 2:1 Addition Compounds
Authors: Maruyama Kazuhiro , Naruta Yoshinori , Otsuki Tetsuo 
Published: July 2006

Abstract
A novel type of the photo-addition compound, 5,8,13,14-tetraoxo-5,5a,6, 7,7a,8,13,13a,13b,14-decahydropentaphene derivatives (3), consisting of two molecules of 1,4-naphthoquinone and one molecule of an olefin was obtained in the photochemical reaction of 1,4-naphthoquinone with olefins. Its structure was determined from spectral data as well as results obtained from the chemical reactions. Olefins which give this type of photo-addition compound are characterized by their bicyclo-ring systems containing considerable ring strains. The reaction mechanism for formation of the compound was discussed in terms of the ring strains of olefins and the nature of the photo-excited 1,4-naphthoquinone.
Studies of the Crystallization Processes of N-Methylquinolinium TCNQ Ion-radical Salts
Authors: Murakami Mutsuaki , Yoshimura Susumu 
Published: July 2006

Abstract
We studied the crystallization processes of the complex ion-radical salt of 7,7,8,8-tetracyanoquinodimethan (TCNQJ and the N-methylquinolinium cation. A variety of solvents, rates of crystallization, and concentrations of the solution gave three groups of crystals. The crystals in the first group, which were crystallized as black rods, occluded the solvent molecules in the crystals, and their resistivities were in the range of 2.8–26 Ωcm. Those in the second group were crystallized into the form of fine needles or fine powders. Although the TCNQ-to-cation ratios in the salts varied from 1.6 to 2.2, their electrical resistivities were almost all the same (about 1.00 Ωcm), and these crystals were thought to have a metastable crystal structure. The crystals in the third group were crystallized in the form of triclinic prisms, which belonged to a stable crystal of a high resistivity (1100 Ωcm). The appearance of multiple forms is interpreted on the basis of Ostwald’s “Law of Stages” of crystallization and also on the basis of information on the structures of the one-dimensional TCNQ, columns of the other complex ion-radical salts of TCNQ.
Transfer Hydrogenation and Transfer Hydrogenolysis VII. The Mechanism of Hydrogen Transfer from 2-Propanol to Olefins Catalyzed by Dihydridotetrakis(triphenylphosphine)ruthenium(II)
Authors: Imai Hideaki , Nishiguchi Takeshi , Kobayashi Masaki , Fukuzumi Kazuo 
Published: July 2006

Abstract
The dihydride complex, RuH2(PPh3)4, has been found to be an excellent catalyst for the hydrogen transfer from 2-propanol to olefins. For cyclohexene in toluene solution, the rate law at 80°C was:
Rate=\frac0.04[C]_o[D]1+24[P]
where [C]0, [D] and [P] are the concentration of the catalyst, 2-propanol and triphenylphosphine, respectively. It is pressumed that active intermediates of the reaction are not Ru(IV)-species but Ru(0)-species. The rate determining step of the reaction is inferred to be the dehydrogenation of 2-propanol, that is, the hydrogen transfer from the alcohol to Ru(0)-complex to form a hydride complex by oxidative addition.
Sum Rule Consideration of Molecular Photoelectron Spectra. Substituted Ethylenes
Authors: Yamazaki Tomoko , Kimura Katsumi 
Published: July 2006

Abstract
The ionization-energy sum rule previously proposed has been applied to photoelectron spectra of three series of chloro-, bromo-, and methyl-substituted ethylenes C2H4−mXm (m=1 and 2; X=Cl, Br, and CH3) in the He(I) region. The total sums of ionization energies were obtained in the p-type region and the partial sums of ionization energies were interpreted in terms of in-plane and out-of-plane molecular orbitals. The following conclusions have been deduced: (1) The experimental total and partial sums are almost constant in the cis-, trans-, and iso-di-substituted ethylenes. (2) The experimental total and partial sums linearly increase with increasing number of the substituents, the slopes leading to useful informations about orbital energies. (3) Such linear relationships are supported by CNDO/2 and MINDO/2 calculations. (4) The experimental total and partial sums are approximately reproduced in terms of several appropriate Iocalized-molecular-orbital energies based on the photoelectron data of simplest molecules.
Effect of Inorganic Electrolytes on the Cloud Point of Polyoxyethylene Dodecyl Ether
Authors: Tokiwa Fumikatsu , Matsumoto Tadao 
Published: July 2006

Abstract
The cloud points of polyoxyethylene dodecyl ether in the presence of different types of inorganic electrolytes have been determined. The cloud points can be expressed by the empirical equation: (C.P.)s⁄(C.P.)0=1+A\sqrtCs+BCs where (C.P.)0 and are the cloud Points with and without an electrolyte, respectively, Cs is the electrolyte concentration, and A and B are constants.
Photochemistry of N-(4-Dimethylaminobenzylidene)aniline
Authors: Ohta Hiroyuki , Tokumaru Katsumi 
Published: July 2006

Abstract
Irradiation of N-(4-dimethylaminobenzylidene) aniline, contrary to an earlier report, does not give cis-4,4′-bis(dimethylamino)stilbene and azobenzene, however, its triplet state has, exceptionally as an acyclic imine, enogh lifetime at 77 K to exhibit phosphorescence.
Electrical Behavior of Alkali Metal Cation–TCNQ Anion Radical Simple Salts under Very High Pressures.
Authors: Shirotani Ichimin , Onodera Akifumi , Sakai Nobuko 
Published: July 2006

Abstract
The electrical resistance of alkali metal cation–TCNQ anion radical simple salts was measured over the wide pressure range from 0 to 500 kbar at room temperature. The least resistivities for Group A (Li–, Na–, K–, and Rb(I)–TCNQ) are about 0.2–3 Ωcm, while those for Group B (Rb(II)– and Cs–TCNQ) are about 0.06–0.1 Ωcm. The possibility of insulator-metal transition at high pressures is discussed. Above 140–175 kbar the electrical resistance of simple TCNQ salts increases with an increase in the pressure and drifts upward with the time. The solid-phase reaction is observed under very high pressures.
General Anharmonic Force Constants of Carbon Disulfide
Authors: Suzuki Isao 
Published: July 2006

Abstract
Twelve force constants in the general quartic force field of carbon disulfide have been determined by a least-squares method from the available spectroscopic data on four isotopic species of carbon disulfide: 12C32S2, 13C32S2, 12C32S34S, and 13C32S34S. A reasonable set of force constants is obtained together with a set of the third-order parameters λ1, λ2, λ3, and δ which appear in Fermi coupling off-diagonal matrix elements. From the converged set of force constants, l-type doubling constants for a few π-vibrational states are calculated through a direct numerical diagonalization method of vibrational Hamiltonian matrix. They agree well with the observed l-type doubling constants.
Molecular Structure of Trimethylene Sulfide as Studied by Gas Electron Diffraction with Joint Use of Rotational Constants
Authors: Karakida Ken-ichi , Kuchitsu Kozo 
Published: July 2006

Abstract
The molecular structure of trimethylene sulfide (thietane) has been determined by an analysis of electron diffraction intensities combined with the rotational constants determined by microwave spectroscopy by Harris et al.: rg(C–S)=1.847±0.002 Å, rg(C–C)=1.549±0.003 Å, rg(Cα–H)=1.09±0.02 Å, rg(Cβ–H)=1.12±0.04 Å, ∠C–S–C(rav)=76.8±0.3°, ∠H–Cα–H(rav)=112±4°, ∠H–Cβ–H(rav)=114±5° and the dihedral angle, ∠C2SC4–C2C3C4(rav)=26±2°. The uncertainties represent estimated limits of error. The definitions of the geometrical parameters have the usual physical significance except that the normal coordinate representing the large-amplitude ring-puckering motion is extrapolated to its equilibrium position. The conventional formula used in the joint analysis has been modified to account for the large-amplitude vibration.
The Crystal and Molecular Structure of trans-Bis(trimethylphosphine)propynyl-1-(4′-dicyanomethylene-cyclohexa-2′-5′-dien-1-ylidenl-3,3-dicyano-2-methyl-prop-2-en-1-ylplatinum, a Reaction Product of trans-Bis(trimethylphosphine)bis(propynyl)platinum and 7,7,8,8-Tetracyanoquinodimethane
Authors: Onuma Ken-ichi , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami 
Published: July 2006

Abstract
The molecular structure of the title complex has been determined from three-dimensional X-ray diffraction data. The crystal belongs to the monoclinic system, space group P21/c, a=14.934(2), b=8.997(1), c=20.221(3)Å, β=97.44(2)°, Z=4. The molecular structure showed that the tetracyanoquinodimethane (TCNQ) molecule has reacted with one of the propynyl groups of trans-{(PMe3)2Pt(C≡CMe)2} : part of the TCNQ is bonded to the α-carbon atom and the other part to the β-carbon of the propynyl ligand. The platinum atom has a squareplanar geometry; Pt–P=2.302(5) and 2.290(5), Pt–C(C≡CMe3)=2.009(15) and Pt–C(reacted)=2.057(15) Å.
Thermochemical Properties of Lanthanoid-Iron-Perovskite at High Temperatures
Authors: Katsura Takashi , Kitayama Kenzo , Sugihara Tadashi , Kimizuka Noboru 
Published: July 2006

Abstract
The standard Gibbs energy of formation of \barCFeO3(\barC=La, Nd, Sm, Eu, Gd, Tb, and Dy) from metallic iron, \barC2O3, and oxygen has been determined at temperatures from 1473 to 1673 K. Based on the free-energy data, the heat of reaction and the entropy change resulting from the reaction have been calculated. The values of the heat of reaction of LaFeO3, NdFeO3, SmFeO3, EuFeO3, and GdFeO3 (the first group) were identical, −107 kcal/mol, at the present temperature interval. However, the values of the heat of reaction of TbFeO3 and DyFeO3 (the second group) decreased with an increase in the temperature. The entropy change of each reaction in the first group was constant, independent of the temperature, and each value decreased in the sequence from LaFeO3 to GdFeO3. The entropy change of the second group decreased with an increase in the temperature. The change of the standard Gibbs energy was intimately related to the ionic radii of \barC-ions, and the relationship between the Gibbs energy and the tolerance factor has been clarified.
Cobalt(III) Complexes Containing Large Chelate Rings. I. Syntheses and Properties of Bis(ethylenediamine)-1,ω-diaminoalkanecobalt(III) Complexes
Authors: Ogino Hiroshi , Fujita Junnosuke 
Published: July 2006

Abstract
New cobalt (III) complexes, [Co(en)2(H2N(CH2)nNH2)]X3 (n=4, 10, 12 and 14), [Co2(en)4(H2N(CH2)nNH2)2]X6 (n=4, 5, 6, 8, 10 and 12), [Co(en)2(H2N(CH2)4NH3)2]X5 and [CoCl(en)2(H2N(CH2)12NH3)]X3 were isolated from the products of reactions between [CoCl2(en)2]Cl and 1,ω-diaminoalkane in dimethylsulfoxide, with the aid of SP-Sephadex column chromatography. For n=5, 6 and 8, no monomeric [Co(en)2(H2N(CH2)nNH2)]3+ was observed. This result is compatible with instability of the medium size rings in organic compounds. The elution behaviors on Sephadex column and the visible and ultraviolet absorption spectra of the new complexes were also described.
Dry Grinding on a Pigment Mixture. I. The Effect of α-Copper Phthalocyanine as a Lubricant on the Mechanochemical Transformation of Calcium Carbonate
Authors: Kawashima Norimichi , Meguro Kenjiro 
Published: July 2006

Abstract
α-Copper phthalocyanine and calcium carbonate were mixed and ground with a grinder, and then the surface properties of the mixtures were investigated in comparison with the grinding time by means of X-ray diffraction analysis, electron-micrograph observation, and the specific surface area as obtained by the B.E.T. method. In the grinding process, the crystal decays of both α-copper phthalocyanine and calcium carbonate were observed. Particularly, the calcite-aragonite transformation occurred in the case of calcium carbonate. However, the addition of some α-copper phthalocyanine to calcium carbonate interfered with the transformation of calcium carbonate. As a conclusion, it was evident that the surface of calcium carbonate was covered with α-copper phthalocyanine and that the grinding of calcium carbonate was interfered with by the lubricating action of α-copper phthalocyanine.
The Reaction of N-Substituted Carbonimidic Dihalides with Grignard Reagents. The Generation of Alkyl or Aryl Halides from Grignard Reagents
Authors: Tanaka Sakuya , Okano Masaya , Tanimoto Shigeo 
Published: July 2006

Abstract
The reaction of N-alkyl- or N-aryl-carbonimidic dihalides with Grignard reagents afforded α-elimination products, isocyanides, rather than substitution ones. Two kinds of alkyl or aryl halides were produced concomitantly in this reaction: one kind consisted of halides generated from the Grignard reagents used, and the other, of halides the halogens of which had been derived from the dihalides. The ease of formation of these halides was found to decrease in the order: iodide&gt;bromide&gt;chloride, regardless of which substrate served as the source of a halogen atom. A probable reaction mechanism is proposed.
Studies on the Catalytic Properties of Synthetic Zeolite A. V. Site Selectivity of Silver Ion in (Agex, Caex)-A
Authors: Nitta Masahiro , Ogawa Kiyoshi , Aomura Kazuo 
Published: July 2006

Abstract
The X-ray diffraction pattern and the propane-adsorption capacity of (Agex, Caex)-A zeolites were determined as a function of the degree of ion exchange. From the change in diffraction intensity and the molecular sieving effect, it was deduced that Ag+ ion prefers site I to site II.
The C–O Bond Cleavage of Allyl Ethers by Rhodium Compounds
Authors: Wayaku Masami , Kaneda Kiyotomi , Imanaka Toshinobu , Teranishi Shiichiro 
Published: July 2006

Abstract
Allyl ethers were cleaved by rhodium compounds under mild conditions to give aldehydes and hydrocarbons. This reaction can be extended to allyl esters.
Ligand-Ligand Interaction in Tris(2,2′-bipyridyl) and Tris (1,10-phenanthroline) Complexes of Nickel(II)
Authors: Ohno Takeshi , Kato Shunji 
Published: July 2006

Abstract
UV spectra of [Ni(2,2′-bipyridyl)3]Cl2 and [Ni(2,2′-bipyridyl)(H2O)4]Cl2 in the mixed solvent of methanol and water (4:1) were measured at 4.2 K. No difference between the spectra indicates a small splitting (&lt;90 cm−1) between the exciton states extending through the three 2,2′-bipyridyls. Since the UV spectrum of [Ni(1,10-phenanthroline)3]Cl2 has a band with the progression as that of [Ni(1,10-phenanthroline)(H2O)4]SO4, a molecular exciton interaction between the three 1,10-phenanthrolines is not strong.
Photosensitized Oxygenation of Unconjugated Cyclic Dienes
Authors: Horinaka Akio , Nakashima Ruka , Yoshikawa Masaharu , Matsuura Teruo 
Published: July 2006

Abstract
The present investigation was undertaken in order to see whether singlet oxygen-oxidation of unconjugated cyclic dienes having spatially close double bonds causes a particular transannular reaction as previously observed with 1,5-cyclooctadiene which gave 4-hydroxy-5-cyclooctenone. Most cyclic dienes tested underwent normal “ene” reaction to give allylic hydroperoxides. Thus, on dye-sensitized photooxygenation followed by reduction with sulfite, dicyclopentadiene, cis,trans-1,5-cyclodecadiene, trans,trans,trans1,5,9-cyclooctadiene, 1,4-cyclooctadiene, 1,3-cyclooctadiene and germacrone yielded a stereoisomeric mixture of tricyclo[5.2.1.02,6]decan-4,8-diene-3-ols, cis,cis-2,7-cyclodecadienol, a stereoisomeric mixture of two 2,5,9-cyclododecatrienols, 2,4-cyclooctadienol, endo-3,8-peroxide of cyclooctene, and germacra-3,7(11),10(14)-trien-9-ol-6-one(E), respectively. Under similar conditions, norbornadiene, and cis,cis-1,6-cyclodecadiene remained virtually unchanged.
Potentiometric Analysis and Fundamental Technique
Authors: Shigemasa Yoshihiro , Shimao Masayuki , Sakazawa Chikahiro , Matsuura Teruo 
Published: July 2006

Abstract
The formose reaction, the calcium hydroxide-catalyzed condensation of formaldehyde to monosaccharides, was potentiometrically analyzed. The oxidation-reduction potential varied in a characteristic way and gave information of considerable importance. Some appreciable transition points in the oxidation-reduction potential curve showed satisfactorily the occurrence of a phase change such as an induction period and saccharide-forming and saccharide-decomposing stages. With regard to the fundamental operating conditions, vigorous stirring and an increase in the dissolved oxygen elongated the induction period. Furthermore, the latter diminished the yield of saccharide under the lower limit of the critical range of the calcium hydroxide concentration.
Restricted Rotation Involving the Tetrahedral Carbon. XV. Restricted Rotation about a Csp8–Csp2 Bond in 9-Aryltriptycene Derivatives
Authors: Nakamura Mikio , Oki Michinori 
Published: July 2006

Abstract
A series of 9-aryltriptycene derivatives have been prepared and their internal rotation about the CAr–C9 bond has been examined by DNMR technique. The PMR behavior of these compounds is best interpreted by assuming a back and forth rotation rather than a full rotation. The barriers to rotation of compounds with one substituted benzo group have been found to be in the range 13–15 kcal/mol, whereas those with two substituted benzo bridges are lower than 9 kcal/mol. The low barrier of these compounds relative to 9-alkyltriptycenes is attributed to the rise in energy of the ground state. The stable conformation of the 9-aryltriptycenes is also discussed.
The Effect of the pH on the Adsorption of an Ampholytic Surfactant, N-Dodecyl-β-alanine, at the Aqueous Surface
Authors: Nakamura Akio , Tajima Kazuo , Sasaki Tsunetaka 
Published: July 2006

Abstract
The effect of the pH on the adsorption of an ampholytic surfactant, N-dodecyl-β-alanine (NDA), at the nitrogen/solution interface was studied by the radiotracer method, using a tritiated compound. The saturated amount of NDA adsorption was found to depend on the pH of the bulk solution; it shows a flat maximum in the isoelectric region from pH 4 to 10, and decreases distinctly on the both acid and alkaline sides. The Gibbs adsorption isotherm for an aqueous solution of the ampholytic surfactant was derived. Using this relation, the amount of adsorption in the pH range from 2 to 6 was calculated from the surface tension vs. concentration and the surface tension vs. pH relations observed for the NDA solution. The calculated values were in good agreement with those obtained by the radiotracer method. The degree of dissociation of the adsorbed monolayer was estimated from the pH dependence of NDA and the chloride ion adsorption.
A Convenient Synthesis of α-Bromophenylacetic Acid from Benzaldehyde Using Methyl (Methylthio) methyl Sulfoxide
Authors: Ogura Katsuyuki , Furukawa Shigeko , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
1-Methylsulfmyl-1-(methylthio)-2-phenylethylene (2a) and 1-methylsulfinyl-1-(methylthio)-2-(p-chlorophenyl)ethylene (2b) reacted with bromine in various solvents to give α-bromophenylacetic acid derivatives. It should be noted that α-bromophenylacetic acid and α-bromo(p-chlorophenyl) acetic acid were mainly obtained by the reaction of bromine with 2a and 2b, respectively, in acetic acid.