bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemistry of α-Haloaldehydes. II. Base-catalyzed Condensation of α-Haloaldehydes with Methyl Chloroacetate
Authors: Takeda Akira , Tsuboi Sadao , Hongo Toru 
Published: July 2006

Abstract
The Darzens-type condensation of α-haloaldehyde (2) with methyl chloroacetate has been studied. The reaction of aliphatic α-chloroaldehydes afforded 4-chloro-2,3-epoxyalkanoates (4). The reaction of 2-bromo-2-methylpropanal (2d) with methyl chloroacetate gave α-chloro-γ,γ-dimethyl-Δα,β-butenolide (7) as a major product. α-Bromo-n-alkanal gave a mixture of many minor products.
Sterically Controlled Syntheses of Optically Active Organic Compounds. XX. Synthesis of Optically Active Alanine from α-Bromopropionamides
Authors: Okawara Tadashi , Harada Kaoru 
Published: July 2006

Abstract
The treatment of N-benzylchloroacetamide with sodium hydride resulted in the formation of N,N′-dibenzyldiketopiperazine which was converted to glycine after hydrolysis and hydrogenolysis. In a similar way, N-alkyl-α-bromopropionamides, in which the alkyl groups were chiral, were treated with sodium hydride and optically active alanine was obtained after hydrolysis and hydrogenolysis. When an optically active (S)-(−)- or (R)-(+)-α-methylbenzyl group was used as a chiral center, the optical activity of alanine was very low. When (S)-(−)-α-ethylbenzylamine was used, optically active (S)-alanine (optical purity 6–25%) was obtained. The use of (S)-(−)-α-(1-naphthyl)ethylamine resulted in the formation of (R)-alanine (opposite configuration, optical purity 23–27%). The overall yield of optically active alanine is in the range 11–36%.
An Interstitial-Electron Model for the Structure of Metals and Alloys. III. Interpretation and Correlation of Properties of Group I–V Metals
Authors: Johnson Oliver 
Published: July 2006

Abstract
The interstitial-electron model for metals supplements the concepts of band theory to give a detailed interpretation of the properties of metals. The instantaneous picture of vacant and electron-occupied interstices given by the model clarifies the complex gradations in electrical conductivity which are not explained by an electron per unit volume term. The consideration of polarization of the itinerant electron cloud by ion cores with high positive fields and of interpenetration of the more deformable ion cores by itinerant electrons is another new feature of the model. The interstitial-electron model leads to the expectation of parallel gradations for electronic heat capacity and magnetic susceptibility and an inverse relation of both of these properties with electrical conductivity. The presence of (\bare2) in the metal structure is associated with a positive Hall Coefficient for a metal, and a new correlation between positive Hall Coefficient and superconductivity for a metal is pointed out.
On the Interaction of Sodium Alkyl Sulfate with Alkylpyridinium Chloride and with Alkyltrimethylammonium Bromide in a Solution
Authors: Mitsuishi Masaru , Hashizume Mieko 
Published: July 2006

Abstract
The interaction between sodium alkyl sulfate and alkylpyridinium chloride or alkyltrimethylammonium bromide has been studied quantitatively by means of the conductometric method. The equilibrium constants of the reactions between them have been found to increase with an increase in the length of the alkyl chain. When the sum of the carbon atoms in an alkyl sulfate and of those of an alkylpyridinium chloride or of alkyltrimethylammonium bromide is less than twenty, no reaction has been found to take place. When it is larger than twentysix, precipitates of the complex have been found. The interaction has been found to depend greately on the length of the alkyl chain. The interaction decreases the heat content and increases the entropy.
Lone Pair Ionization Potentials of Carboxylic Acids Determined by He(I) Photoelectron Spectroscopy
Authors: Watanabe Iwao , Yokoyama Yu , Ikeda Shigero 
Published: July 2006

Abstract
Photoelectron spectra of some simple carboxylic acids and halogen substituted acetic acids were observed. Each spectrum contains a band which is associated with the ionization from an oxygen lone pair (n0) orbital of carboxyl group. The band associated with the n0 orbital is clearly separated from other bands, and its shape and width are quite similar among the various carboxylic acids. In the spectra of halogen substituted acetic acids, n0 band appears around the region of the lone pair bands of halogen atoms. The ionization potentials for oxygen lone pair orbital of carboxylic acids are measured and compared with the results of some semi-empirical SCF MO calculations. The agreements are quite satisfactory when ionization potentials are obtained from the difference of total energies of neutral molecule and its corresponding cation calculated using CNDO/2 or INDO method. MINDO/2 method also gives excellent values when Koopmans’ theorem is applied.
Water Content on Metal Oxides. I. Water Content on Silica Gel, Magnesium Oxide, Zinc Oxide, and Titanium Dioxide
Authors: Morimoto Tetsuo , Naono Hiromitu 
Published: July 2006

Abstract
The surface water content has been determined on silica gel, magnesium oxide, zinc oxide, and titanium dioxide by means of active hydrogen analysis and by the successive-ignition-loss method. Except for magnesium oxide pretreated at 100 °C, it has been found that the water contents obtained from the two methods on every oxide tested are in good agreement with each other. The successive-ignition-loss method gives an extraordinarily high value of water content on magnesium oxide pretreated at 100 °C, probably because of the retention of inner hydroxyl groups. The present results indicate that the two methods are equally reliable for the quantitative determination of the water content on metal oxides. Moreover, the simultaneous application of both methods make it possible to estimate each amount of surface hydroxyl groups and physisorbed water molecules.
Analysis of Metals by Solid-Liquid Separation. Spectrophotometric Determination of Cadmium by Extraction of Cadmium Salt of Oxine with Melted Naphthalene
Authors: Fujinaga Taitiro , Satake Masatada , Yonekubo Tatsuo 
Published: July 2006

Abstract
A method is described for the spectrophotometric determination of a minute quantity of cadmium. A cadmium complex stable at 90°C is easily extracted with melted naphthalene. The resulting mixture of cadmium complex and naphthalene is dissolved in dimethylformamide and absorbance of the solution is measured at 400 nm. Effects of pH, amounts of oxine, naphthalene and diverse salts are given.
The Mass Spectra of 3-Aryl-5-chloromethyl-1,2,3-oxathiazolidine-2-oxides
Authors: Nishiyama Tomihiro , Yamada Fukiko 
Published: July 2006

Abstract
The mass spectra of 3-phenyl- (I), 3-tolyl- (II), 3-chlorophenyl- (III), and 3-trichlorophenyl- (IV), -5-chloromethyl-1,2,3-oxathiazolidine-2-oxides have been obtained. The major path in the electron impact-induced cleavage of all the compounds involves the loss of SO2 and Cl from each molecular ion (M). The M–SO2–Cl ions show the loss of CH=CH2, followed by the loss of the hydrogen radical and HCN. On the other hand, in compounds II, III, and IV, the M–SO2–Cl ions show the loss of the ring-substituted methyl or chloro radical. The above fragmentation pathways associated with metastable transitions or the chlorine isotopic clusters for each ion of III or IV have been outlined and discussed for each group of compounds.
Synthesis and Biological Activity of Peptides Related to Eledoisin. III. C-Terminal Hexapeptide Amides Modified in Methionine and Isoleucine Residues
Authors: Sugano Hiroshi 
Published: July 2006

Abstract
New analogs of hexapeptide related to eledoisin containing N-methylmethionine and α-hydroxy-γ-methylthiobutyric acid in place of the methionine, and α-hydroxyisovaleric acid in place of the isoleucine, were synthesized in order to obtain some information about the role of the amide bond in the peptide backbone. The former two were practically inactive in the rabbit pressure assay. These results indicated that the amide bond between the leucine and the methionine residues was important for the depressor activity of eledoisin. The last one showed very little activity. The results supported the suggestion made previously that the amide bond between the phenylalanine and the isoleucine residues is important in eliciting the biological response. The role of the amide bonds in the peptide backbone of eledoisin was also discussed.
The Formation of Tin-Nitrogen Bonds. V. The Selective 1-Substitution Reaction of Tetrazoles by the Reaction of 5-Substituted 2-(Tri-n-butylstannyl)tetrazoles with Methyl Iodide, Methyl p-Toluenesulfonate, Dimethyl Sulfate, and Ethyl Bromoacetate
Authors: Isida Tyûzô , Akiyama Tetsuo , Nabika Kiyoshi , Sisido Keiiti , Kozima Sinpei 
Published: July 2006

Abstract
The selective 1-substitution reaction of tetrazole was developed by the treatment of 5-substituted 2-(tri-n-butylstannyl)tetrazoles with methyl iodide, methyl p-toluenesulfonate, dimethyl sulfate, or ethyl bromoacetate at room temperature. This selectivity was introduced by blocking the 2-nitrogen with the tri-n-butyltin group against the 2-substitution. In the case of 5-substituted 2-(trimethylstannyl)tetrazoles, a low selectivity was observed. The possible reaction pathways have been discussed.
A Study on the Photochemistry of α,β-Unsaturated γ-Lactones. II. Photoisomerization of 3-Ethylidene-4,5-dihydro-2(3H)-furanone
Authors: Ohga Kazuya , Matsuo Taku 
Published: July 2006

Abstract
On irradiation of cis-3-ethylidene-4,5-dihydro-2(3H)-furanone with 2537 Å light, both the cis-trans isomerization of the exocyclic double bond and transformation into the β,γ-unsaturated isomer, 3-vinyl-4,5-dihydro-2(3H)-furanone, were observed. By the use of sensitizers such as acetone, acetophenone, p-methoxyacetophenone and benzophenone, it was possible to induce cis-trans isomerization exclusively. On the basis of the solvent effect and the wavelength dependence of the reactions, transformation into the β, γ-unsaturated isomer and cis-trans isomerization were suggested to proceed via T2(n,π*) and T1(n,π) states, respectively.
Chemical Studies on the Mistletoe. II. The Structure of Viscumamide, a New Cyclic Peptide Isolated from Viscum album Linn. var. coloratum Ohwi
Authors: Okumura Yasuaki , Sakurai Atsushi 
Published: July 2006

Abstract
A new cyclic peptide, viscumamide (C30H55N5O5) was isolated from Viscum album Linn. var. coloratum Ohwi, and the structure Ia (Remark: Graphics omitted.) was assigned to this substance from gas-chromatographic studies on the products of partial hydrolysis.
The Electrochemical Fluorination of Benzenes and Pyridines
Authors: Inoue Yoshio , Nagase Shunji , Kodaira Kazuo , Baba Hajime , Abe Takashi 
Published: July 2006

Abstract
The electrochemical fluorination of several aromatic compounds (benzene, fluorobenzene, chlorobenzene, m-dichlorobenzene, anisole, o-chloroanisole, thiophenol, p-chlorothiophenol, m-thiocresol, 2-chloropyridine, and 3-chloropyridine) has been carried out. Perfluorocyclohexane was the principal product from benzene and fluorobenzene. In addition, chloro-derivatives of perfluorocyclohexane were produced from chlorobenzenes. Anisoles gave fully-saturated perfluoroethers, together with cleaved products. Extensive cleavage was observed in the fluorination of thiophenols and chloropyridines, and fluorocarbons and sulfur hexafluoride or nitrogen trifluoride were characteristic products. New compounds were also formed, trifluoromethyl 2-chlorodecafluorocyclohexyl ether from o-chloroanisole, and 3-chlorodecafluoropiperidine and 2-chloroundecafluoropentane from 3-chloropyridine.
Application of the RRKM Theory to Energized Ethylene Formed in the Vacuum-ultraviolet Photolysis of n-Paraffins
Authors: Akimoto Hajime , Obi Kinichi , Tanaka Ikuzo 
Published: July 2006

Abstract
The Rice-Ramsperger-Kassel-Marcus treatment has been applied to the energized ethylene produced in the vacuum-ultraviolet photolysis of C2H6, C2D6, C3H8, C3D8, n-C4H10 and n-C4D10. The energy spread in the energized ethylene has been evaluated assuming modified statistical distribution of liberated energy among fragment species. The calculated nonequilibrium unimolecular decomposition rate constant for the process C2H4(C2D4)→C2H2(C2D2)+H2(D2) could satisfactorily reproduce the experimental pressure dependence of ethylene to acetylene ratio. Non-statistical kinetic energy Ek seems to appear for the primary decomposition of the n-paraffins. Its value ranges from zero for the elimination of methane and ethane from propane and n-butane, respectively, at 147.0 nm to about 25 kcal mol−1 for the elimination of hydrogen from ethane at 123.6 nm.
ESR Studies on Radical Anions of Calicene Derivatives
Authors: Konishi Shiro , Niizuma Shigeya , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
Two calicene derivatives, 1,2,3,4-tetrachloro-5,6-diphenylcalicene and 1,2,3,4-tetrachloro-5,6-di-n-propylcalicene, were reduced with an alkali metal in degassed tetrahydrofuran and the ESR spectra of the resluting monoanion radicals were investigated. It was found that in both anion radicals the unpaired spin does not exist on the five-membered ring, and is localized only on the other part. In the latter anion radical, the five-membered and three-membered rings were found to be twisted toward each other at about 45°, a line width alternation caused by hindered internal rotation of two adjacent n-propyl groups being observed. The potential barrier for the hindered rotation was determined to be about 1.5 kcal/mol.
The Crystal Structure of Dinicotinic Acid
Authors: Takusagawa Fusao , Hirotsu Ken , Shimada Akira 
Published: July 2006

Abstract
The crystal structure of dinicotinic acid has been determined by X-ray diffraction method. Two kinds of twinning crystals were obtained by changing the pH of the aqueous solution by recrystallization. The crystals are monoclinic with the space group of P21/c and with cell dimensions of a=9.702, b=11.153, c=6.587 Å, and β=107.8°. The crystal structure was solved by an inspection of the sharpened Patterson map. The final R value is 5.93% for 1181 observed reflections. The dinicotinic acid molecule takes an intermediate structure between the neutral molecule and the zwitter ion with an approximate C2v symmetry. The bond lengths and angles related by the C2v symmetry are equal within the limits of experimental error for those of the two carboxyl groups. The C(2)–N(1)–C(6) bond angle is 119.8°, which lies between those of protonated and unprotonated species of the pyridine ring. The molecules lie approximately on planes parallel to the (001) plane at z=1⁄4 and 3/4. Each molecules on the same plane is joined through two kinds of hydrogen bonds (O–H···O; 2.594 Å, O···H···N; 2.515 Å), related by two-fold screw axes, with four neighboring molecules. In the O···N hydrogen bond, the hydrogen bonding distance and angle are 2.515 Å and 174° and the O–H and N–H distances are 1.23 and 1.29 Å, which are equal within the limits of experimental error. Therefore, it may be considered as an example of the single minimum hydrogen bond of the O–H···N hydrogen-bond type. The existence of two kinds of twins may be interpreted on the basis of the layer structure.
Absorption Band in the Near-Ultraviolet Region Observed for Binuclear Copper(II) Complexes
Authors: Kida Sigeo , Nishida Yuzo , Sakamoto Masatomi 
Published: July 2006

Abstract
Elucidation of the origin of near-ultraviolet absorption believed to be characteristic of binuclear copper(II) complexes was attempted. The absorption was attributed to charge transfer transitions from nonbonding orbitals of bridging oxygen atoms to the vacant metal d-orbital. Appearance of the band in the near-ultraviolet region was interpreted in terms of the red-shift due to the decreasing s-character of the nonbonding orbitals enforced by the steric requirement of the complex. On this basis, the spectra of dialkoxo- or dihydroxo- bridged complexes and of copper alkanoates can consistently be explained.
Oxidation of p-Tolyl Triphenylmethylhydrazo Sulfone
Authors: Kojima Minoru , Kamigata Nobumasa , Minato Hiroshi , Kobayashi Michio 
Published: July 2006

Abstract
In order to synthesize and study the decomposition of p-tolyl triphenylmethylazo sulfone, p-tolyl triphenylmethylhydrazo sulfone was oxidized by various oxidizing agents. Although it was oxidized fairly easily by mercury(II) oxide or potassium permanganate, the azo compound formed was unstable and decomposed immediately with evolution of nitrogen. The main products were p-tolyl triphenylmethyl sulfone and p-tolyl p′-benzhydrylphenyl sulfone; both are ascribable to the recombination of p-toluenesulfonyl and triphenylmethyl radicals.
Variations of Heat of Immersion of Ferric Oxyhydroxides in Water with Structural Changes by Heating
Authors: Ishikawa Tatsuo , Inouye Katsuya 
Published: July 2006

Abstract
The relationship between the activity of ferric oxyhydroxides (α-, β-, and γ-FeOOH) and structural changes has been investigated by determining the heat of immersion in H2O and H2O vapor adsorption. For each ferric oxyhydroxide, the monolayer capacity of H2O adsorption and the heat of immersion decreased with the progress of transformation into α-Fe2O3. Above the transformation temperature the heat of immersion increased with the outgassing temperature. The heat of immersion of α-Fe2O3 obtained by outgassing each ferric oxyhydroxide at 400 and 500 °C increased with the accompanying increase in crystallite size. β-FeOOH showed higher heat of immersion and larger monolayer capacity per unit surface area than other ferric oxyhydroxides. It is presumed that the higher heat of immersion and larger monolayer capacity observed for β-FeOOH are ascribed to micropores in β-FeOOH crystals produced by the removal of molecular water originally contained.
X-Ray Analysis of the Domain Structure of the 1:1 Complex of Carbazole–TCNQ
Authors: Kobayashi Hayao 
Published: July 2006

Abstract
The crystal structure of the 1:1 complex of carbazole–TCNQ was investigated by X-ray diffraction. Analysis of sharp spots and diffuse streaks in the diffraction patterns revealed that the crystal is composed of an ordered domain and a disordered one. The ordered domain is made up from two types of ordered molecular arrangements, whereas the disordered one consists of a one-dimensionally disordered structure. The structures of the two ordered domains are closely related with each other. They both contain mixed stack columns of alternating carbazole and TCNQ usually observed in charge transfer (CT) complexes. The existence of various types of domain structures as shown by diffraction patterns of many crystals grown from acetone, acetonitrile and tetrahydrofuran solutions can be interpreted in terms of the combinations of ordered and disordered domains. No CT band appears in the visible absorption spectra of the acetone solution of carbazole–TCNQ, whereas the spectra of the powdered crystals show a CT band at about 18000 cm−1. The calculation of SCF-MO-CI of the system of the carbazole–TCNQ, pair indicates a weak CT interaction.
An Experimental Study of Gibbs-Donnan Membrane Equilibria Across Permselective Membranes Which Involve the Ions of Strong Inorganic Electrolytes
Authors: Tamamushi Reita 
Published: July 2006

Abstract
The Donnan membrane equilibria arising across permselective collodion matrix membranes were studied both by a static and a flow method in systems which contain only simple strong electrolytes at relatively high concentrations, up to 0.4 equiv/l. Experimental details of the flow method and its advantage in studying the ion activity behavior are presented. From the measurements of equilibrium concentrations and Donnan membrane potentials the ratios of ion activity coefficients were calculated for the following pairs of electrolytes in mixed solutions: sodium chloride–sodium nitrate, sodium sulfate–ammonium sulfate, potassium oxalate–ammonium sulfate, and potassium oxalate–ammonium oxalate. The experiments prove the feasibility of determining the ratios of ion activity coefficients in mixed solutions at concentrations where other methods lose their usefulness.
Conformation of Poly(S-benzyl-l-cysteine) in Solution
Authors: Maeda Hiroshi , Inoue Takashi , Tsunoda Masa-aki , Ikeda Shoichi 
Published: July 2006

Abstract
Conformation of poly(S-benzyl-l-cysteine) was investigated by measurements of optical rotatory dispersion, infrared absorption and viscosity in dichloroacetic acid (DCA)–chloroform mixtures. Transition from random coil to the β-structure was confirmed to occur when DCA content of the solvent was reduced below 40% (v/v). Both dispersion parameters a0 and b0 increased as the polymers were transformed into the β-structure. Viscosity of the polymer solution changed only slightly with accompanying the transition. This was interpreted in terms of the formation of intramolecular β-structure. In the region where the β-structure was dominant both optical rotatory parameters and viscosity were independent of solvent composition. Such behavior has been rarely observed in the β-coil transition of other polypeptides. The β-structure of poly(S-benzyl-l-cysteine) was shown to be more stable than that of poly(O-benzyl-l-serine) as referred to respective random coil conformations.
Studies on the Interactions of 1-Substituted 2,4-Dinitrobenzenes with Hydroxide Ion in Aqueous Dimethyl Sulfoxide by Means of the Rapid Scan Spectrophototometer
Authors: Hasegawa Yoshinori , Abe Takehiro 
Published: July 2006

Abstract
The initial interactions of m-dinitrobenzene, 2,4-dinitroanisole, 2,4-dinitrofluorobenzene, and 2,4-dinitrochlorobenzene with hydroxide ion in aqueous dimethyl sulfoxide were studied with a rapid scan spectrophotometer. In all the cases, the first transient colored-species assigned to 1-hydroxy-3-substituted-2,6-dinitrocyclohexadienates were observed at initial stages before the formations of the second colored-species having the π-electronic structures of 1,3-dinitropentadienyl anion were complete.
Restricted Rotation Involving the Tetrahedral Carbon. VII. Rotation About the Carbon-Group IV Single Bond
Authors: Suzuki Fumio , Oki Michinori , Nakanishi Hiroshi 
Published: July 2006

Abstract
9-t-Butyl-, 9-trimethylsilyl-, 9-trimethylgermyl- and 9-trimethylstannyl-1,2,3,4-tetrachloro-9,10-dihydro-9,10-ethenoanthracenes were prepared by the addition of tetrachlorobenzyne to 1-(CH3)3M-substituted naphthalene. The carbon compound showed very high barrier to rotation, whereas the coalescence phenomenon of three methyl signals was observed for silicon, germanium, and tin compounds. The barrier (ΔG\eweq) to rotation at 298 K was obtained as 19.1±0.5, 17.2±1.2, and 11.7±0.4 kcal/mol for Si, Ge, and Sn compounds, respectively. The decrease in the barrier on increasing the atomic size was attributed to the release of repulsive interaction to a greater extent, since the longer bond length should result in the larger displacement of the methyl group even though the bond angle deformation is the same.
An Attempt at Simultaneous Observation by Polarizing Microscopy and by Differential Thermal Analysis
Authors: Sasaki Kunihisa Kazuko 
Published: July 2006

Abstract
An apparatus for differential thermal analysis using a polarizing microscope has been developed. With this device it is possible to observe the state of a sample under the heating or cooling conditions with a polarizing microscope and to obtain the DTA curve simultaneously. The transformations of several substances—potassium laurate, ammonium nitrate and tripalmitin— were observed. The results are in agreement with those obtained by X-ray diffraction. The relation between the appearance of Phase III of NH4NO3 and the water content of the sample was considered on the basis of the microscopic observations. In the case of tripalmitin, two types of transformations were observed under cooling conditions. The relation between the DTA curve of tripalmitin and the heating rate has also been studied. The apparatus may be useful for the study of liquid crystals.