bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity Coefficients of Aqueous Xylose and Maltose Solutions
Authors: Uedaira Hatsuho , Uedaira Hisashi 
Published: July 2006

Abstract
Osmotic and activity coefficients of aqueous xylose and maltose solutions at 25°C are measured by the isopiestic vapor pressure method. Densities of these solutions are also determined at 25°C. The activity coefficients of water in these solutions show that both xylose and maltose solutions do not behave as regular solutions. Second virial coefficients for xylose and maltose are calculated from partial molar volumes of the solute and the solvent at infinite dilution and empirical equations of water activity coefficient. The coefficients calculated for xylose and maltose are 111 and 248 cc/mol, respectively. Second virial coefficients for these sugars and a few other sugars are approximately proportional to the molecular weight. This relation is explained by the van der Waals model.
Zero-point Average Structure of Acetaldehyde
Authors: Iijima Takao , Kimura Masao 
Published: July 2006

Abstract
The zero-point average structure of acetaldehyde has been determined by the use of the moments of inertia and the average distances, obtained by microwave spectroscopy and electron diffraction respectively. The following rz parameters have been determined: 1.515±0.005 Å for C–C, 1.207±0.004 Å for C=O, 1.073±0.002 Å for C–H(methyl), 123°48′±9′ for ∠CCO, and 108°52′±17′ for ∠HCH of the methyl top.
Microwave Spectrum, Barrier to Internal Rotation, and Dipole Moment of trans-Crotonaldehyde
Authors: Suzuki Masao , Kozima Kunio 
Published: July 2006

Abstract
The microwave spectrum of trans-crotonaldehyde has been measured in the frequency region from 8.2 to 36 kMc/sec. The R-branches for the a-type and the R- and Q-branches for the b-type have been assigned. The low J transitions of the a-type and all of the b-type transitions are split into the A-level and the E-level by the internal rotation of the methyl group. The apparent rotational constants for the A- and E-levels have been obtained from the pseudo-rigid rotor approximation as AA=32636.58 Mc/sec, AE=32627.57 Mc/sec, B=2183.30 Mc/sec, and C=2073.32 Mc/sec. From these values it can be concluded that this molecule is of the s-trans form. The barrier height of the hindering rotation of the methyl group is 1730±10 cal/mol. The value of the total dipole moment is 3.72±0.28 D.
ESR Studies on the Reaction of an OH Radical in α,β-Unsaturated Aldehyde
Authors: Ichikawa Takahisa , Kuwata Keiji 
Published: July 2006

Abstract
ESR studies on the UV irradiated α,β-unsaturated aldehyde - hydrogen peroxide mixtures have been done at low temperature in order to examine the reactions of an OH radical with aldehyde: formyl hydrogen-abstraction, methyl hydrogen-abstraction, and addition to an olefinic bond. It has been shown that abstraction of a methyl hydrogen by an OH radical occurs in croton-aldehyde, whereas β-addition of an OH radical to an olefinic bond takes place in methacrolein and acrolein. A formyl hydrogen is unreactive with an OH radical in any case. The distribution of unpaired electron in the radicals was also discussed.
Refinement of the Structure of Tohdite 5Al2O3·H2O
Authors: Yamaguchi Goro , Okumiya Masataro , Ono Shuichiro 
Published: July 2006

Abstract
The structure of tohdite, 5Al2O3·H2O, was determined by Yamaguchi Yanagida, and Ono (1964). Least-squares refinements based on their structure have been carried out using X-ray-powder data. The final R factor of the reflection intensity reduced to 0.08 from the initial value of 0.26.
Coumarins. VI. The Acid-catalyzed Reaction of Phenols with β-Aminocrotononitrile
Authors: Sato Kikumasa , Ohashi Masao , Amakasu Takeshi , Takeda Katsuhiko 
Published: July 2006

Abstract
A new synthesis of 4-methylcoumarins has been developed by means of the acid-catalyzed condensation of phenols with β-aminocrotononitrile. Such monohydric phenols as phenol or cresols reacted with β-aminocrotononitrile in polyphosphoric acid (PPA) to give 4-methylcoumarins in poor yields, along with a good yield of 6-amino-3-cyano-2,4-lutidine (III). In contrast, 7-substituted-4-methylcoumarins were obtained in 23–44% yields from resorcinol and its monomethyl ether. On the other hand, when β-aminocrotononitrile was heated in PPA, the lutidine (III) was obtained in a high yield. Its precursor, 4-amino-1,3-dicyano-2-methylpenta-1,3-diene (XI), was isolated under mild conditions. These results suggest that β-aminocrotononitrile may undergo the preferential self-dimerization to the lutidine (III) rather than the intermolecular condensation with phenols.
Copolymerization of Formaldehyde and Succinic Anhydride in the Presence of Carbon Dioxide
Authors: Yokota Hisao , Toriuchi Yahiko , Kagiya Tsutomu , Fukui Kenichi 
Published: July 2006

Abstract
A Study of the copolymerization of formaldehyde and succinic anhydride was carried out in a liquid carbon dioxide solution without adding any catalyst. A copolymer, in which a small number of succinic units was inserted into the sequence of oxymethylene units because of the low rate of copolymerization of succinic anhydride, was formed. With enhancing the concentration of succinic anhydride, the content of succinic units in the copolymer slightly increased. At reaction temperatures up to 120°C, the molecular weight of the copolymer decreased with a rise in the temperature, whereas the content of succinic units increased to about 3 mol%. The copolymerization proceeded rapidly, so the reaction immediately reached equilibrium. From the results of the study by X-ray diffractiometry, the crystal structure of the copolymer can be said to be similar to that of polyoxymethylene, but the crystallinity of the copolymer decreased as the content of succinic units increased. The rate of thermal degradation, which started from the end-groups of the copolymer was decreased by ester linkgae. The thermal-degradation temperature was enhanced as the content of succinic units increased. The copolymer also showed a high resistivity to the folding of the film, even though it had not been treated so as thoroughly to esterify the endgroups of the copolymer.
Studies on Formaldehyde-Condensation Resin. VII. Isolation of Mono-, Di-, Tri-, and Tetramethylolacetoguanamines
Authors: Uragami Tadashi , Oiwa Masayoshi 
Published: July 2006

Abstract
The reaction of acetoguanamine with formaldehyde was carried out in the presence of basic catalyst under various conditions, and mono-, di-, tri-, and tetramethylol derivatives of acetoguanamine were purely isolated. Their structures were identified by elemental analyses, infrared absorption spectra, NMR spectra, and chemical analyses of methylol groups.
ESR Spectra of the System of the Transition Metal Compound and Trialkyl Aluminum. II. The System of the Vanadium Compound and Trialkyl Aluminum
Authors: Nozawa Yasuo , Takeda Masatami 
Published: July 2006

Abstract
The ESR spectra of the homogeneous organometallic catalyst system of VOA2-AlEt3 (I) and VCl4-AlEt3 (II) were measured in benzene, toluene, n-hexane and tetrahydrofuran solutions. A superhyperfine structure of nine lines with a g-value of 1.9917, and with a hyperfine splitting of 4.2 gauss on each eight line due to the 51V nucleus, was observed in the systems of I and II in the aromatic solvents at any Al/V ratio from 1 to 15. The same type of spectrum was observed in the VA3-Al(isoBut)3 system in a benzene solution at Al/V ratios higher than 3. In the system of II, the single line was observed at Al/V ratios up to 5. At higher ratios the superhyperfine structure appeared to overlap on the single line. On the basis of these facts, it may be considered that the vanadium atom was reduced to the zerovalent state and was then complexed with aromatic solvents in these systems. This suggests the presence of a sandwich complex such as (Remark: Graphics omitted.) where X=H or CH3.
Semi-empirical Unrestricted SCF-MO Treatment for Valence Electron Systems. I. Application to Small Doublet Radicals
Authors: Yonezawa Teijiro , Nakatsuji Hiroshi , Kawamura Takashi , Kato Hiroshi 
Published: July 2006

Abstract
A semi-empirical SCF method for valence electron systems including a differential overlap previously proposed by the present authors is here extended to molecules with an open-shell structure. The unrestricted Hartree-Fock method is applied, and the one-centre and part of two-centre σ-π-type exchange repulsion integrals, playing an essential role in spin-density calculations, are included in the calculations. The calculated spin densities are divided into the mechanistic (spin-polarization and spin-delocalization) contributions. The spin-polarization mechanism is shown to be important even in cases where the spin delocalization mechanism has usually been considered to be dominant (e.g., ethyl and vinyl radicals). The calculated spin densities of π-electron radicals (methyl, ethyl, allyl, and trans-butadienyl anion radicals) and of σ-electron radicals (vinyl, formyl, NO2, CO2−, CN) are discussed. Their hfs constants and mechanistic contributions are calculated; for the methyl and vinyl radicals these are shown to be strongly angular-dependent. The calculated potential curve and the hfs constants of the vinyl radical lead to the CCHa angle, θ\simeq135°; furthermore, the Hα and Cβ hfs constants are shown to be negative. Generally, the calculated proton hfs constants agree satisfactorily with the experimental data and with other calculations except in the case of the formyl radical. The atomic dipoles of some σ-electron radicals are calculated, and some interesting features common to all the σ-electron radicals studied are found.
Kinetics of the Adsorption of Water and Electrical Conduction in Amorphous Ferric Oxide
Authors: Furuichi Ryusaburo , Sato Norio , Okamoto Go 
Published: July 2006

Abstract
Amorphous ferric oxide was prepared by precipitation in a mixture of ammonium hydroxide and ferric nitrate at 90°C, after which it was calcinated in air at a constant rate of 10°C/min up to 200°C. The rate of the adsorption on the amorphous oxide was measured by a gravimetric method. An equation of the Elovich type was obtained: dq⁄dt=k′p0.63exp(−α′q⁄RTp0.5), where k′ and α′ are constants; q, the amount of adsorbed water, and p, the pressure. This kinetics can be interpreted by a model of a two-stage adsorption process, the van der Waals adsorption and the charge-transfer adsorption, the latter stage being assumed to be rate-determining. The effect of adsorbed water on the direct-current conductivity of the oxide, i, is formulated as i=i0exp(aq). Assuming that the adsorbed water is acting as a donor-type impurity and that the ionization energy decreases with the concentration of impurity, the relation between i and q can be derived from the theory of the semiconduction of an n-type conductor.
The Ultrasonic Study of Aqueous Solutions of Alkyl-Substituted Urea
Authors: Sasaki Katsutaka , Arakawa Kiyoshi 
Published: July 2006

Abstract
An ultrasonic investigation of aqueous solutions of alkyl-substituted urea was made by means of an ultrasonic pulse technique in order to study the influence of the solutes upon the structure of solvent. The ultrasonic velocity and absorption were measured in solutions of 1,3-dimethyl-urea and 1,3-diethylurea in the frequency range from 5 to 45 Mc/sec. The temperature was varied from 10 to 40°C, and the concentration from 0.2 to 4 mol/l. Within the range of frequency no relaxation frequency was observed for both solutions. From the data on absorption coefficent and viscosity, the magnitude of absorption due to structural relaxation was calculated. It was found that structural absorption in dimethylurea solutions is slightly larger, and in diethylurea solutions much larger than that of the urea solutions. From these results, it is concluded that 1,3-dimethylurea is a structure breaker for the open-packed structure in water, the ability being smaller than that of urea, and that, for the behavior of 1,3-diethylurea molecule in water, the structure-forming ability of the ethyl group is found to surpass the structure-breaking effect of the residual part of the molecule.
The Effects of Tetraalkylammonium Salts on the Structure and the Temperature of the Maximum Density of Water
Authors: Wada Goro , Miura Masako 
Published: July 2006

Abstract
The effects of the tetraalkylammonium halides on the temperature of the maximum density of water were measured by means of dilatometry. Contrary to the expectation that the hydrophobic nature of the alkyl radicals would elevate the temperature of the maximum density of water, these salts lowered it, as other, more usual salts do, obeying the Despretz rule. Among the salts represented as R4NBr, where R is either H or an n-alkyl radical, the Despretz constant, kD, increases in the sequence: H&lt;CH3&lt;C2H5&lt;n-C3H7&lt;&lt;n-C4H9, while the deviation of kD from k, which is a hypothetical constant of the ideal mixing where there is no interaction between the solute and the solvent, varies in the following sequence: H\simeqCH3\simeqC2H5\simeqn-C3H7 &lt;&lt;n-C4H9. The latter fact is attributable to the specific occurrence of a clathrate-like structure formed in the aqueous solution, only when R is n-C4H9. This is in accordance with another peculiarity of (n-C4H9)4NBr which shows a minimum in its partial molar volume at a certain concentration in water.
Bond Lengths of Dimethylacetylene as Determined by Gas Electron Diffraction
Authors: Tanimoto Mitsutoshi , Kuchitsu Kozo , Morino Yonezo 
Published: July 2006

Abstract
The bond distances of dimethylacetylene have been determined by electron diffraction to be rg(C–C)=1.4675±0.0013 Å, rg(C≡C)=1.2135±0.0013 Å, rg(C-H)=1.1158±0.0059 Å, and ∠C–C–H=110.7±0.4°, the uncertainties representing the limits of experimental error. The carbon-carbon single bond length has been found to be in good agreement with that in butadiene, as was qualitatively to be expected from Stoicheff’s empirical rule. The carbon-carbon triple bond length appears to be longer than that of acetylene and shorter than that of diacetylene by a few thousandths of an angstrom. The dependence of the triple-bond lengths on the environment is discussed in terms of the change in conjugation and hyperconjugation.
Shielding Effect of Ortho-Substituents on Magnetic Moments and d-d Bands in Chloro-N-phenylsalicylideneiminatocopper(II)
Authors: Kato Michinobu , Muto Yoneichiro , Jonassen Hans B , Imai Kyoko , Katsuki Kazuko , Ikegami Seishi 
Published: July 2006

Abstract
Complexes with the formula, Cu(\overset1O·C6H4·\overset2CH=N–Ph–X)Cl, where Ph-X is a mono- or disubstituted phenyl group, were prepared. A dimeric structure was postulated for these complexes based on the observed subnormal magnetic moments and the chemical formula. For these complexes, a linear relation was observed to exist between the magnetic moments, μeff25°C, and the d–d band positions, \ ildenumax. The d–d bands of the dimeric complexes with o-substituents appeared at shorter wavelengths than those with m- or p-substituents irrespective of the polar nature of the substituents. A similar ortho-effect was also observed for the magnetic moments; complexes with o-substituents were observed to have smaller moment values than those with m- or p-substituents. The oryho-effect was also observed in the d–d bands of the monomeric bis-complexes Cu(\overset1O·C6H4·\overset2CH=N–Ph–X)2 and their d–d bands when X=o-substituents appeared at shorter wavelengths than those with m- or p-substituents. These ortho-effects decreased for the solution spectra of the monomeric complexes.
Synthetic Studies of the Derivatives of Acetylene. I. Reactions of 5-Bromopent-3-en-1-yne
Authors: Sato Kikumasa , Hirayama Masao 
Published: July 2006

Abstract
The preparation of pent-2-en-4-ynylamine and pent-2-en-4-ynylthiol and their derivatives from 5-bromopent-3-en-1-yne was studied. Moreover, in connection with the preparation of the bromide, the rearrangement-bromination of vinylethynylcarbinol was found to give three isomeric bromides, 5-bromopent-trans-3-en-1-yne, 5-bromopent-cis-3-en-1-yne, and 3-bromopent-1-en-4-yne. Pent-2-en-4-ynylamine was obtained from 5-bromopent-3-en-1-yne by two methods, by the hydrolysis of the hexaminium salt and by the cleavage of N-(pent-2-en-4-ynyl)phthalimide. The reaction of 5-bromopent-3-en-1-yne with potassium hydrosulfide and the decomposition of ethyl pent-2-en-4-ynylxanthate by alcoholic ammonia gave pent-2-en-4-ynylthiol.
Synthetic Reactions by Complex Catalysts. XIII. Carbonylation of Amines by Group IB and IIB Metal Compound Catalysts
Authors: Saegusa Takeo , Kobayashi Shiro , Hirota Kiwami , Ito Yoshihiko 
Published: July 2006

Abstract
The present investigation was undertaken in order to examine the catalytic activities of Group IB and IIB metal compounds in the carbonylation of aliphatic and aromatic amines with carbon monoxide, and in order to compare the catalyst activities with those of other metal compounds. It was found that: i) copper compounds are excellent catalysts for the carbonylation of aliphatic amines to produce the corresponding formamides; ii) the catalytic activities of copper compounds are enhanced by the addition of water; and iii) chloroauric acid catalyzes the carbonylation of aromatic amine, whereas copper compounds do not. The temperature effects on the carbonylation of morpholine were also examined.
Intramolecular Hydrogen Bonding in α-Keto- and α-Alkoxy-carboxylic Acids. VII. Ultraviolet Spectra of Phenylglyoxylic Acid in Various Solvents
Authors: Hirota Minoru , Shinozaki Fumiaki 
Published: July 2006

Abstract
The ultraviolet spectra of phenylglyoxylic acid were determined in various solvents as well as in the mixtures of solvents. A very remarkable hypsochromic shift with increase in intensity was observed when the solvent participates in the formation of hydrogen bond as a hydrogen acceptor. The measurement of the spectra in binary mixtures of the solvents shows that the hypsochromic shift is due to the formation of a 1:1 complex of C6H5COCOOH···solvent type. This hypsochromic shift is interpreted by the destruction of the chelate ring formed by the intramolecular hydrogen bond which enforces the acid molecule to the planar conformation. This view is supported by the simple LCAO-MO calculation on this molecule.
Concentration Polarization Phenomena in Ion-exchange Membrane Electrodialysis. II. The Effect of the Condition of the Diffusion-boundary Layer on the Limiting-current Density and on the Relative Transport Numbers of Ions
Authors: Yamane Reiichi , Sata Toshikatsu , Mizutani Yukio , Onoue Yasuharu 
Published: July 2006

Abstract
The effect of the condition of the diffusion-boundary layer in the ion-exchange membrane electrodialysis on the limiting-current density and on the relative transport numbers of ionic species with the same sign was studied. The limiting-current density in the laminar flow is approximately proportional to the first power of the concentration of the solution, the one-half power of the flow velocity of the solution, and, inversely, the one-half power of the membrane length in the direction of the flow. In the natural convection, it is proportional to the five-quarters power of the concentration of the solution. These experimental results agree with the relation of the equations of the limiting-current density for the electrode process. The change in the relative transport numbers of ionic species with the same sign, such as the magnesium and sodium ions or the sulfate and chloride ions, with the flow velocity, the concentration, and the temperature of the solution, the dimension of the membrane in the direction of the flow, and the current density were observed. The results were explained in terms of the change in the condition of the diffusion-boundary layer.
Electrophotographic Properties of Titanium-Dioxide Resin Dispersion Layers
Authors: Iida Takeaki , Nozaki Hiroshi 
Published: July 2006

Abstract
The electrophotographic properties of titanium dioxide-polymer dispersion layers were studied. The titanium dioxide powder of the rutile type and three well-known polymers, polyvinyl acetate, polyvinyl chloride, and polystyrene, were used. The measurements were done on the corona-charging properties, e. g., the resistivity and the capacitance of the layer, the rising gradient of the surface potential, and the fatigue effect of pre-illumination. The results make it clear that the analysis of an equivalent circuit can be applied to the interpretation of the rising gradient of the surface potential and to that of the dark decay to some extent. Moreover, it is found that the logarithm of the potential of the dark decay decreases proportionally to the cube root of the time at the initial step, while, at the next following step, it decays proportionally to the square root of the time. The mechanism of the dark decay of the surface potential is also discussed.
Absorption Spectra and Circular Dichroisms of Metal Complexes. IV. Dichloro-diamine Type Complexes of Platinum(II) and Palladium(II)
Authors: Ito Haruko , Fujita Junnosuke , Saito Kazuo 
Published: July 2006

Abstract
Absorption (AB) spectra of dichloro(l-tetrahydrogenpropylenediaminetetraacetato)platinum-(II) and palladium(II) and dichloro(d-hydrogendiaminopropionato)platinum(II) and palladium(II) were interpreted on the basis of a comparison of their circular dichroism (CD) spectra with those of dichloro(l-propylenediamine)platinum(II) and palladium(II). The d-d bands of edtaH4 and l-pdtaH4 complexes shifted to longer wavelength as compared with those of l-pn complexes. The shift was discussed, based on the effects of the weaker ligand field strength and apical interaction of the acetato groups of these ligands.
Alkaline Hydrolysis of Aryl Benzenethiolsulfonates
Authors: Oae Shigeru , Nomura Ryuichi , Yoshikawa Yoichiro , Tagaki Waichiro 
Published: July 2006

Abstract
The alkaline hydrolysis of substituted phenyl benzenethiolsulfonates has been investigated. The rate was found to be first order with respect to both hydroxide and ester. The second order rate constant for the unsubstituted ester was found to be 3.2×103 m−1 sec−1 (water 45°C). The Hammett ρ values were found to be ρX,Y=H=2.1 and ρY,X=H=1−1 for (Remark: Graphics omitted.) respectively. The reactivities of three esters, i. e. phenyl benzenethiolsulfonate, -thiolsulfonate and -sulfonate were compared.
Base-catalyzed Condensation of o-Nitroacetophenone. IV. Structure of Dehydro-derivative of Compound A, a Condensation Product
Authors: Sakan Takeo , Kusuda Kousuke , Miwa Toshio 
Published: July 2006

Abstract
The alkaline hydrogen peroxide oxidation of compound A, C17H14O5N2, a base-catalyzed condensation product of o-nitroacetophenone, gave a dehydro compound, C17H12O5N2. The structure of the dehydro compound was deduced from the spectral data of its derivatives to be a (o-nitrobenzoyl)-1-hydroxycarbostyril. The forced hydrogenation of the dehydro compound gave 3-(o-aminobenzoyl)-4-methylcarbostyril, which was synthesized by the condensation of o-aminoacetophenone and ethyl o-nitrobenzoylacetate followed by reduction. Therefore, the dehydro compound proved to be 1-hydroxy-4-methyl-3-(o-nitrobenzoyl)carbostyril. On the other hand, the alkaline hydrogen peroxide oxidation of compound A methyl ether gave o-nitrobenzoic acid and 1-methoxy-3-methyldioxindole along with o-nitroacetophenone. These facts are explained by assuming a transition state which would be controlled by the presence of a hydrogen bonding.