bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equilibrium of Urea Synthesis. I.
Authors: Inoue Shigeru , Kanai Kazumichi , Otsuka Eiji 
Published: July 2006

Abstract
A test of the equilibrium conversion of CO2 to urea was carried out using a batch autoclave. Some results different from those reported by Frèjacques were obtained, as was expected from the latest data on commercial urea plants. The equilibrium conversion reached its maximum value at about 195°C by 5–15% higher than that reported by Frèjacques. On the contrary, at temperatures above 200°C the value was lower, and falled rapidly with the raise of temperature. This phenomenon may be due to the mechanism of the equilibrium of urea synthesis, and not to the experimental method, as our sampling was made directly from the liquid phase. The equilibrium conversion, x, may be expressed with respect to NH3/CO2, a, H2O/CO2, b, and temperature, t, as
(Remark: Graphics omitted.)
Therefore, a limited conversion exists in the conventional urea process.
Infrared Intensities of Sodium, Calcium, and Potassium Hydroxide Crystals
Authors: Kamisuki Toshio , Maeda Shiro 
Published: July 2006

Abstract
The absolute intensities of OH− and OD− stretching absorptions in Na, Ca, and K hydroxide crystals have been measured in the films formed on a quartz window. The thickness of the films was determined by chemical or flame photometric analysis of the solution in which the sample film had been dissolved. The expected difference between OH− and OD− in the dipole-moment derivative, (dμ/dr)OD–(dμ/dr)OH, was observed to be in excellent or moderate agreement with the theoretical value given from Ellison’s equation for Na and Ca. This result also proves that the polarization of dμ/dr is in the O−–H+(D+) direction in these cases. As for K hydroxides, although the numeric results are rather dubious, the intensities are apparently by far greater than the two others, confirming the hydrogen-bond formation in this crystals, as suggested by the crystal structure and vibrational frequencies.
On the Electron-transfer Reaction Rate between Different Molecular Species of Aromatic Hydrocarbons as Measured by ESR
Authors: Suga Kosaku , Aoyagui Shigeru 
Published: July 2006

Abstract
The rate constants of electron-transfer reactions between the anthracene anion radical and pyrene, and those between the former radical and 1,2-benzanthracene, were measured by the ESR method in tetrahydrofuran containing 20 mm of tetra-n-butylammonium perchlorate. In the analysis of the experimental results, correction of the ESR line width was made for the change in the radical concentration caused by the addition of neutral molecules. The rate constants thus obtained were (2.0±0.4)×107m−1sec−1 and (8.1±1.0)×10−7m−1sec−1 respectively at 25°C. Under the same experimental conditions, the rate constants of the electron exchange of anthracene and pyrene with their respective anions were about one-tenth of the rate constants of free anions. This fact led us to the supposition that the anion radicals had been combined with tetra-n-butylammonium ions into stable ion-pairs in our experiment. A semi-empirical method was proposed for the theoretical calculation of the rate constant according to the theory of R. A. Marcus. The agreement of the observed and the calculated rate constants was satisfactory. Further discussion of the dependence of the rate constant on the standard free energy of reaction was made in connection with the so-called “Linear Free Energy Relationship.”
On the Long-range Interactions between Two Hydrogen Atoms and Two Helium Atoms
Authors: Yamabe Tokio , Ishimaru Shingo , Fukui Kenichi 
Published: July 2006

Abstract
The numerical results of the interaction energy between two hydrogen atoms and two helium atoms are examined with the use of exact formulae of the second-order perturbation energy using the Unsöld approximation. It is found that the analytic expression gives a good long-range interaction energy between two hydrogen atoms comparable to the best variational results so far obtained. In the case of two helium atoms, the result lies in between experimental data for large nuclear distances; this seems to support the reliability of the present estimation. Finally, the effectiveness of the Unsöld approximation is remarked on.
The Behavior of Indium(III) Complexes in Several Distribution Systems. II. The Extraction of Indium(III) Halide and Thiocyanate Complexes into 4-Methyl-2-Pentanone, 4-Methyl-2-Pentanol, or Nitrobenzene
Authors: Hasegawa Yuko , Takeuchi Hiroshi , Sekine Tatsuya 
Published: July 2006

Abstract
The solvent extraction of indium(III) from a bromide, iodide, or thiocyanate solution into 4-methyl-2-pentanone(MIBK), 4-methyl-2-pentanol(hexol), or nitrobenzene was determined by using a 114mIn tracer. The extraction was, in general, most effective with MIBK and poorest with nitrobenzene, except from iodide solutions. The extraction with a certain solvent was always better from iodide solutions than from bromide solutions. The extraction from thiocyanate solutions was better than that from iodide solutions in some cases, but it was poorer in other cases, and it was better than that from bromide solutions except with nitrobenzene. Furthermore, it was found that the distribution ratio, determined as a function of the ligand concentration, was always poorer when the aqueous phase contained only the sodium salt of these ligands than when it was 4m Na(X, ClO4) (where X denotes the ligand anion). The extractions from 4m Na(X, C1O4) were analyzed by using the stability constants for the indium complexes with these ligands in the aqueous phase, and the extraction equilibria were determined. From these results, it was concluded that these polar solvents extract not only the uncharged complex, InX3, but also the cationic and/or anionic indium complexes as ion-pairs, with the oppositely charged ions in the background salt, and that, in some cases, the solvent extracts only charged indium species. Thus, the difference in the distribution ratio in the presence and in the absence of the background sodium perchlorate was concluded to be caused not only by the change in the activities due to the change in the total salt concentration, but also by the extraction of ion-pairs of charged indium(III) species, which should be very much enhanced by the presence of the bulk perchlorate.
Polarographic Catalytic Waves of Titanium(IV) Chelates of EDTA and Related Compounds
Authors: Kaneko Hiroko , Ozawa Takeo 
Published: July 2006

Abstract
In the presence of the chlorate ion, the electrode reaction of the various titanium(IV)-chelates is followed by a cyclic process, i.e., an electrochemical reduction of electroactive species generated continuously by coupled chemical oxidation. The reaction rate constant of the regeneration is determined from the ratio of the limiting current observed by the DC polarographic method in the presence of the chlorate ion to that determined without it, and it is calculated using Koutecky’s equation. The complex-forming agent decreases the wave height of the catalytic waves of titanium(IV) chelates, and a clear dependency of the height of the catalytic waves on the dissociation constants of the titanium chelates is found. The catalytic wave heights of the titanium(IV) chelates decrease in the order of oxalic acid, NTA, EDTA-OH, EDTA, and CyDTA; the dependency on the stability seems to be the reverse. The logarithm of the dissociation constant is in a linear relation with the logarithm of the catalytic current. The mechanism is discussed on the basis of the above-mentioned facts.
Spectrophotometric Study on The Extraction of The Ternary Complex Composed of Cobalt(II), 8-Hydroxyquinoline-5-sulphonic Acid and Zephiramine
Authors: Kambara Tomihito , Sugawara Masao 
Published: July 2006

Abstract
8-Hydroxyquinoline-5-sulphonic acid (H2QS) reacts with cobalt(II) in the presence of zephiramine (tetra-decyl-dimethyl-benzyl-ammonium chloride) and gives a yellow green association complex. The ternary complex having an absorption maximum at 405 nm can be extracted into chloroform at pH 6.8–9.3. Beer’s law holds for 2.73–33.0 μg of cobalt(II); molar absorptivity, 1.39×104 cm−1mol−1l. The composition of cobalt(II)-H2QS complexes in water is 1 : 1 at pH 4.4, 1 : 2 at pH 5.8, and 1 : 3 at pH 7.6. The composition of the ternary complex is estimated to be [Co2+(QS2−)2(HQS−)(Z+)3]o. The equilibrium constant for the extraction
K=\frac[Co2+(QS2−)2(HQS−)(Z+)3]o[Co2+][(HQS−Z+)]o3[OH−]2
was determined. It was found that logK=29.01±1.86.
The Reaction and Reaction Products of μ-O2-Dicobalt Ammine Complexes with Nitrites, Thiocyanates, etc.
Authors: Shibahara Takashi , Mori Masayasu 
Published: July 2006

Abstract
In a neutral solution [NH3(en)2CoO2Co(en)2NH3]4+ was found to react with NO2− and SCN− to give [NO2-(en)2CoO2Co(en)2NO2]2+ and [SCN(en)2CoO2Co(en)2NCS]2+ respectively, without causing any cleavage of the O2-bridge, while in an acid solution it was found to be oxidized by NO2− to a μ-superoxo (O2−) complex ion, [NH3-(en)2CoO2Co(en)2NH3]5+. The latter is not affected by NO2−, in contrast with [(en)2Co(μ-NH2,O2)Co(en)2]4+, in which the O2−-bridge is replaced by an NO2−-bridge. The [NO2(en)2CoO2Co(en)2NO2]2+ formed as described reacts with CN− to give [Co2(CN)6(en)2O2]2−. The EPR spectra of some new μ-superoxo complexes which were synthesized by oxidizing some of the above μ-peroxo complexes were measured and compared with those of similar complexes. Infrared and electronic spectra were also taken.
Intramolecular Hydrogen Bonding in α-Keto and α-Alkoxy Carboxylic Acids. VIII. o-Methoxy-Substituted Phenoxyacetic and Phenylthioacetic Acids
Authors: Hirota Minoru , Hirano Go 
Published: July 2006

Abstract
The infrared spectra in the O–H stretching region of several ortho-substituted phenoxyacetic and phenylthioacetic acids were determined in dilute carbon tetrachloride solutions. The O–H stretching absorption of phenoxyacetic acids carrying o-methoxy-substituents shows three absorption maxima, all of these being attributed to the monomeric species, and they are assigned to the free O–H group, the O–H group hydrogen bonded with α-phenoxy oxygen atom and the O–H group hydrogen bonded with methoxyl oxygen atom in the order of decreasing frequency. The O–H stretching absorption at the lower frequency of o-methoxyphenylthioacetic acids is also assigned to the hydrogen bonded monomeric species in which the chelation occurs between the carboxylic O–H group and the methoxyl oxygen atom.
Electric Conduction and Density of Condensed Phosphoric Acids and Their Mixtures with Sulfuric Acid
Authors: Akiyama Akitane , Suzuki Tsuyoshi , Saji Takashi 
Published: July 2006

Abstract
The electrolytic conductivities and densities of condensed phosphoric acids have been measured in the P2O5 concentration range from 55% to 80% at 55.0, 70.0, and 90.0°C. Assuming the proton jump mechanism through the hydrogen bond network of H2O and H3PO4, the molar conductance was calculated and found to be constant in the P2O5 concentration range between 60% and 76%. The investigation has been extended to the mixtures of condensed phosphoric acids and concentrated sulfuric acid. The complex formation of [H4PO4+·HSO4−] and [H3O+·HSO4−] has been suggested in the mixture.
Synthesis of Nδ-Hydroxyornithine
Authors: Isowa Yoshikazu , Takashima Toshiyuki , Ohmori Muneki , Kurita Hideaki , Sato Masanari , Mori Kaoru 
Published: July 2006

Abstract
N δ-Tosyl-Nδ-benzyloxy-Dl-ornithine was synthesized starting from γ-(N-tosyl-N-benzyloxy)-aminopropyl bromide and diethyl acetamidomalonate and resolved enzymatically to give the l- and d-isomers. Removal of one or both of protecting groups gave Nδ-benzyloxyornithine or Nδ-hydroxyornithine. The reduction product of Nδ-hydroxy-l-ornithine was identical with authentic l-ornithine.
Preparation and Thermal Decomposition of 1,4,5- and 1,3,5-Trimethyltetrazolium Iodides
Authors: Isida Tyûzô , Kozima Sinpei , Fujimori Shin-ichirô , Sisido Keiiti 
Published: July 2006

Abstract
1,4,5- and 1,3,5-Trimethyltetrazolium iodides were prepared by the reaction of methyl iodide with 1,5- and 2,5-dimethyltetrazoles, and the reaction of methyl iodide with 5-methyltetrazole. The latter method is more facile for the preparation of these iodides. Upon thermal decomposition of the 1,3,5-trimethyl salt at 130°C, the 1-methyl group was eliminated predominantly to yield 2,5-dimethyltetrazole. When the 1,4,5-trimethyl salt was decomposed at 270°C, a mixture of 1,5- and 2,5-dimethyltetrazole was obtained in 74% and 21% yields, respectively. For the formation of 2,5-dimethyltetrazole from the 1,4,5-trimethyl salt, there has been shown an intermolecular methylation scheme that the 1,4,5-trimethyl salt methylated 1,5-dimethyltetrazole being formed in situ to give the 1,3,5-trimethyl salt.
Copper(I) Perchlorate Complexes of Allyl, 2-Methylallyl and cis-and trans-2-Butenyl Alcohols
Authors: Ishino Yoshio , Ogura Tetsuya , Noda Kenichiro , Hirashima Tsuneaki , Manabe Osamu 
Published: July 2006

Abstract
[Cu(allyl alcohol) (H2O)]ClO4 (abb. Cu(all)(H2O)ClO4), [Cu(allyl alcohol)2(H2O)]ClO4 (abb. Cu(all)2-(H2O)ClO4), [Cu(2-methylallylalcohol)(H2O)]ClO4 (abb. Cu(meth)(H2O)ClO4) and [Cu(cis- and trans-2-butenyl alcohol)2 (H2O)]ClO4 (abb. Cu(cis-and trans- but2 (H2O)ClO4) were synthesized. It was shown by means of equivalent conductance that Cu(all)(H2O)ClO4 is a strong electrolyte of uni-uni valent in acetone. The molecular weight of Cu(all)(H2O)ClO4 obtained from measurements of the direct vapor-pressure depression of acetone showed that the complex is monomeric. The C=C stretching band of the allylic alcohol shifts by about 100 cm−1 to the lower frequency side upon coordination. The chemical shifts of the vinyl protons in these complexes shift by about 0.5–1 ppm to the higher frequency side than those of free alcohols. It was concluded that the allylic alcohol coordinates to the copper atom through both the double bond and the oxygen atom. The equilibrium constant corresponding to Cu(trans-but)+2(H2O)ClO4+2cis-2-butenyl alcohol=Cu(cis-but)+2(H2O)ClO4+2trans-2-butenyl alcohol in 2-butenyl alcohol was estimated to be 9.82 at 25°C and the enthalpy change was estimated to be −3.13kcal/mol.
The Synthesis and Configuration of Fukiic Acid Derivatives
Authors: Matsumoto Takashi , Hidaka Kazuo , Nakayama Teruko , Fukui Kenji 
Published: July 2006

Abstract
The methylation of 3,4-dimethoxyphenylpyruvic acid (II) gave the corresponding methyl ester (III), which was then subjected to a Wittig reaction with carbomethoxymethylenetriphenylphosphorane to give the corresponding fumaric (IVa) and maleic (IVb) acid derivatives in a 1:3 ratio. The cis-hydroxylation of IVa and IVb with an aqueous solution of potassium permanganate and magnesium sulfate gave methyl (±)-thero-2,3-dihydroxy-4-(3,4-dimethoxyphenyl)-3-methoxycarbonylbutyrate (Va) and its (±)-erythro-isomer (Vb) respectively. The dimethyl esters, (±)-Va and (±)-Vb, were converted to the corresponding monomethyl esters, (±)-VIIa and (±)-VIIb respectively, via two dicarboxylic acid derivatives, (±)-VIa and (±)-VIb. The resolution of (±)-VIIb with brucine gave (+)-VIIb and (−)-VIIb, which were then converted to (+)-Vb and (+)-VIb and to (−)-Vb and (−)-VIb respectively. The synthetic (+)-Vb was shown to be identical with the natural O,O′-dimethylfukiic acid dimethyl ester by a mixed fusion and by comparisons of their IR and NMR spectra. From the present study it is evident that natural fukiic acid has an erythro configuration.
The Substituent Effect. IV. Proton NMR Chemical Shifts of Phenols
Authors: Tsuno Yuho , Fujio Mizue , Takai Yoshio , Yukawa Yasuhide 
Published: July 2006

Abstract
NMR chemical shifts of the hydroxyl proton of m- and p-substituted phenols were determined in aprotic DMF and DMSO solutions. The effect of substituents on the hydroxy chemical shift was correlated much more excellently with our LArSR relationship, Δδ=ρ(σ0+rΔ\barσ\barR), than with simple Hammett equation, ρσ0 or ρσ−. The correlation resulted in ρ=1.655 and r=0.639 in DMF with correlation coefficient 0.9992 and ρ=1.530 and r=0.673 in DMSO with a correlation coefficient 0.9990. Anisotropy effect of any substituent was not significant. The deviations of particular substituents were ascribed to the modification of the electronic characters of substituents due to strong substituent-solvent interactions in DMF (or DMSO). The inductive and resonance substituent constants, (σi)DMF and (Δ\barσ\barR)DMF, were determined, on the basis of the assumption that the solvent-modification of a given substituent is practically the same at both meta and para positions.
Preparation of Reinforcing Fillers from Japanese Acid Clays with Lime and by Calcination. I. Availability of Raw Materials for Preparing Hard Clay and the Properties of Products
Authors: Rai Hideki , Yamada Junkichi 
Published: July 2006

Abstract
Reinforcing fillers for elastomers were prepared from three representative specimens of Japanese acid clay by treatment with hydrated lime (CaO 10%), subsequent calcination (600°C, 1.5 hr), and mechanical disintegration. Physicochemical properties of the products such as hygroscopicity, pH, diphenylguanidine (DPG) adsorption, specific gravity, and bulk density were determined in comparison with those of raw materials. Morphological and structural features were investigated by means of electron microscopy, X-ray diffraction, infrared and far infrared spectroscopy, DTA, and TGA. The reinforcing effects on SBR-1502 were compared with those of Dixie Clay and Silene EF. The following results were obtained. (1) Acid clays containing montmorillonite and α-cristo-balite as principal constituents are suitable for the preparation of the fillers, but not the clay containing halloysite mineral as a major component in the randomly mixed-layers of kaolinite and montmorillonite with no excess silica. (2) Irreversible contraction as well as the formation of calcium silicates took place in montmorillonite minerals. Calcium silicate is formed in two states, one covering the surface of montmorillonite minerals and the other being set free. This gives rise to remarkable changes in adsorptivity, pH, swelling, bulk density, and specific gravity. Thus it becomes possible to use acid clays as reinforcing fillers. Hygroscopicity and the pH could be made about the same as those of Silene EF. The DPG adsorption capacities could be reduced as low as that of Dixie Clay. The products thus obtained greatly increased in bulk density and exhibited an average property of Dixie Clay and Silene EF in reinforcing SBR-1502.
The Determination of the Diffusion Coefficient and the Maximum Surface Concentration of Polyvinylpyrrolidone by Means of a Hanging Mercury Drop Electrode
Authors: Yoshida Tadashi , Ohsaka Tetsuya , Nomoto Shigemitsu 
Published: July 2006

Abstract
Subsequently to the previous work with a dropping mercury electrode (DME), the diffusion coefficient (D) and the maximum surface concentration (Γm) for polyvinylpyrrolidone (PVP) were determined in a In sulfuric acid solution by means of a hanging mercury drop electrode (HMDE). The values of D and Γm for PVP were obtained separately by means of the equation for a semi-infinite spherical diffusion for HMDE. The results for D were compared with the values evaluated from the Stokes-Einstein equation or with those previously published. The results for Γm are also shown in comparison with those values to be expected from the data obtained by the use of DME or HMDE on the assumption of linear diffusion and D, or in comparison with the results published by Jehring. It was also confirmed that the HMDE used by the authors is almost satisfactory for the determination of D and Γm in this case.
Electronic Structures of Thianthrene, Phenothiazine, and Related Heterocyclic Compounds
Authors: Kamiya Mamoru 
Published: July 2006

Abstract
Systematic studies were made on thianthrene, phenoxathiin, diphenylene dioxide, phenothiazine, and phenoxazine for the correlation between the folded structure and electronic spectra in terms of the semiempirical SCF–MO–CI method. The calculated results are in good agreement with the experimental results, the folded structure being prominent in the sulfur-containing molecules. The dihedral angle dependency of the all valenceelectronic energy and ionization potential was also studied by the extended Hückel method.
The Solvent Extraction of Zinc(II) in Sodium Perchlorate-halide Solutions with Trioctylphosphine Oxide
Authors: Moriya Hiromitsu , Sekine Tatsuya 
Published: July 2006

Abstract
The solvent extraction of zinc(II) in 1m sodium perchlorate ionic media containing chloride, bromide, or iodide ions at 25°C was determined as a function of the halide-ion (X−) concentration by using the zinc-65 tracer. From the extraction data with isopropyltropolone (IPT) in chloroform, the formation of the ZnX+ complex was observed, but the stability constants of these complexes were not large (ZnCl+: β1 is 100.00, ZnBr+: β1 is less than 10−0.5and the formation of ZnI+ is negligible), and the higher complexes were negligible in all cases. The extraction of zinc(II) from these media with methylisobutylketone (MIBK) was not effective, although the extracted species could be identified as ZnX2. The extraction with trioctylphosphine oxide (TOPO) in hexane, on the other hand, was much better than that with MIBK. From the distribution ratio determined as a function of the halide and TOPO concentrations, the extracted species were concluded to be Zn(ClO4)2(TOPO)4, ZnX(ClO4)(TOPO)3, and ZnX2-(TOPO)2. The extraction constants for these species were determined by a graphic analysis of the data, and it was concluded that the extractabilities are larger in the order: iodide&gt;bromide&gt;chloride. From these data, it is clear that, if a suitable and effective neutral extractant is employed, the extractions of the above complexes are possible, even from aqueous solutions in which practically no complex is formed.
Elimination Reactions of Ethylene Halohydrins on Solid Catalysts
Authors: Mochida Isao , Anju Yasuhide , Kato Akio , Seiyama Tetsuro 
Published: July 2006

Abstract
Elimination reactions of ethylene chlorohydrin and ethylene bromohydrin were studied over solid acids, solid bases, and metals supported by silica gel at 300°C using a microcatalytic gas chromatographic technique in order to elucidate the relationship between the elimination selectivity and the nature of active sites. Acetaldehyde was exclusively formed on solid acids and MgO. However, ethylene oxide as well was formed on solid bases. The ratio seems to depend on the basic strength of the solid bases. On the metals, ethylene was formed in addition to acetaldehyde. The former was the principal product on Pd and Pt. From these results, it was concluded that acetaldehyde was formed on acidic sites by halide-ion abstraction; ethylene oxide, on basic sites by proton abstraction, and ethylene, on less polar sites of metals by halogen atom abstraction.