bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Properties of Water in Macromolecular Gels. VI. The Relationship between the Rheological Properties and the States of Water in Macromolecular Gels
Authors: Aizawa Masuo , Suzuki Shuichi , Suzuki Teruo , Toyama Hiroshi 
Published: July 2006

Abstract
The relationship between the rheological properties and the states of water in macromolecular gels is investigated by both the rheological and nuclear magnetic resonance methods. In accordance with the stress-strain curve, macromolecular gels are shown to be classifiable into: (1) an agarose type of gel which shows great gel strength and brittleness at breaking; (2) a κ-carrageenan type of gel showing great gel strength, but ductility at breaking, and (3) a λ-carrageenan type of gel, which has very little gel strength and is pasty. The dependence of the NMR line-width of water in gels on the polymer concentration and on the temperature reveals that the motional state of water in gels is restricted in this order: the agarose type of gel&gt;the κ-carrageenan type of gel&gt;the λ-carrageenan type of gel. These results show that the state of water is closely related with the rheological properties of macromolecular gels.
Laser Photolysis Studies on the Ionization of N-Vinylcarbazole and N-Ethylcarbazole in the Presence and Absence of Electron Acceptors
Authors: Taniguchi Yoshio , Nishina Yasuzo , Mataga Noboru 
Published: July 2006

Abstract
Formation of solvated ion radicals in the N-vinylcarbazole (VCZ)-and N-ethylcarbazole (ECZ)-electron acceptor systems in polar solvents has been studied by means of laser photolysis, transient photoconductivity and transient absorption measurements. Ion radical formation due to the encounter collision between an excited VCZ or ECZ and electron acceptor was confirmed directly. In the absence of electron acceptor, formation of cation radicals of carbazoles due to biphotonic process was observed in polar solvents. The Sn←S1 spectra of these molecules were observed both in polar and nonpolar solvents.
The Ultraviolet Absorption Spectra and Hydrolysis of Bis (acetylacetonato) nickel (II) in Dichloromethane
Authors: Isobe Kiyoshi , Nakamura Yukio , Kawaguchi Shinichi 
Published: July 2006

Abstract
The ultraviolet spectrum of Ni(acac)2 in dichloromethane shows two maxima, at 265 and at 300 nm. The intensity ratio of these two bands is very sensitive to the water content of the solvent, the high-energy band decreasing and the low-energy band increasing with the water content. It is thus suggested that the trimeric Ni(acac)2might have only one absorption band, at 265 nm, in dichloromethane completely free from donor impurities. The UV spectrum of Ni(acac)2 in dichloromethane changes with time due to the hydrolytic reaction. Even in the solvent containing 4.54×10−3m water, acetylacetone was freed from the complex in the yield of 34.4% after 48 hours’ standing. A minute amount of the residual complex was isolated; its tetrameric structure is suggested on the basis of its UV spectrum in methanol.
Kinetics of the Reaction at the Silver–Silver Sulfide Interface
Authors: Mizusaki Junichiro , Fueki Kazuo , Mukaibo Takashi 
Published: July 2006

Abstract
The reaction rate at the Ag/Ag2S interface was determined as a function of silver activity of Ag2S in the temperature range 215–400°C. The silver activity of Ag2S at the interface was measured electrochemically by means of an Ag/AgI electrode. The reaction rate was measured by the direct sulfurization method (Wagner’s pellet method) and by Rickert’s method using Ag/AgI/Ag2S/Pt cell. The rates obtained by the two methods were in good agreement. It was found that this is a first-order reaction with respect to the activity of sulfur in Ag2S and that the rate equation is given by
v=1.0×104{exp(−18000⁄RT)}aseqv cm−2s−1 (i)
The following reaction mechanism prevails at the interface.
2Ag(A)+S(Ag2S)→2Ag+(Ag2S)+S2−(Ag2S) (ii)
Chemical Analysis of Mixtures of Metals by a Logarithmic Extrapolation Method
Authors: Nagaosa Yukio , Yonekubo Tatsuo 
Published: July 2006

Abstract
Decomposition of the ternary molybdophosphoric acid of titanium(IV), vanadium(V), zirconium(IV) and niobium(V) by complexing agents such as oxalate, citrate or tartrate was found from a kinetic study to be of first-order with respect to each metal ion. The half lives and activation energies of decomposition were also examined. From the results chemical analysis of mixtures of the metals was studied by a logarithmic extrapolation method, utilizing the difference in decomposition rate. Metals in binary systems such as Zr–Nb, V–Zr, Nb–V, Ti–V and Ti–Nb could be determined simultaneously within a relative error of ±5%. Determination of 0.01∼0.2 mg of vanadium was carried out in the presence of titanium (0.1 mg), zirconium (0.5 mg), niobium (0.5 mg) and other diverse ions. Iron(III), aluminum, germanium(IV) and iodide interfered with the determination.
Potential-step Anodic Stripping Voltammetry
Authors: Komatsu Masahiro 
Published: July 2006

Abstract
The application of anodic potential-step stripping voltammetry for the determination of metal ion was investigated. From the dependence of stripping current (ia,d) on electrode radius, the rotational speed of the stirring rod in electrodeposition and electrodeposition time for Cd(II) in 1 M KCl, the diffusion-controlled process could be theoretically predicted. The calibration curves of Cd(II), Mn(II), Ni(II), Zn(II), and Sb(III) were found to be linear in the range 0.01–0.1 ppm, and those of Tl(I), Cu(II), Pb(II), Sn(II), Bi(III), and In(III) in the range 0.02–0.2 ppm, by analysis at time t=1.25 sec on current-time curves. The ratio ia,d⁄ia,p increased in the order n=3&lt;2&lt;1, where ia,d is the anodic diffusion current obtained by the potential-step method, and ia,p the anodic peak current obtained by the linearly varying potential method. The ratio of irreversible electron transfer reaction differed from that of the reversible one. The coefficient of variation in the measurement of peak heights was ±3% for 0.1 ppm or 0.2 ppm of metal ion.
The Internal Friction of Glasses Containing Alkali under an Electric Field
Authors: Sakamura Hiroyasu , Imaoka Minoru 
Published: July 2006

Abstract
The change of the internal friction of sodium silicate and sodium borate glasses under an electric field was studied by means of a torsion pendulum technique. It was found that the internal friction increased under an electric field and that the increase was related to the numbers of vibration, the strength of the electric field, and the Na2O content. The increase in internal friction in the glasses with a high Na2O content was large because of the electrolysis of the glasses, which resulted in the removal of sodium ions. It was proposed that the internal friction increased because the removal of sodium ions was promoted by torsional oscillation under an electric field and that the deformation of the network took place around holes which were left behind by the removal of the sodium ions.
The Hydrolysis of Ferric Complexes. Magnetic and Spectrophotometric Studies of Aqueous Solutions of Ferric Salts
Authors: Kiyama Masao , Takada Toshio 
Published: July 2006

Abstract
Ferric chloro, ferric aquo, and ferric sulfato complexes in acidic solutions have been hydrolyzed at temperatures below 70°C to form polynuclear complexes of iron(III). Magnetic and spectrophotometric studies have then been carried out in order to clarify the nature of the polynuclear complexes. From these studies, their empirical formulas are presumed to be Fe2(OH)2Cl2O, Fe2(OH)3(NO3)3, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2. The iron ions in these polynuclear complexes are in a high spin state, as are those in the ferric complexes, iron oxides, and oxyhydrates. It is proposed that, in all these polynuclear complexes except Fe3(OH)2(SO4)7⁄2, edge-shared octahedral dimer units are antiferromagnetically linked with one another by hydroxy or oxo bridging. When the hydrolysis temperature is raised, these polynuclear complexes are further hydrolyzed to form precipitates. The complexes of Fe2(OH)2Cl2O, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2 give β-FeOOH, α-FeOOH, and RFe3(OH)6(SO4)2 (R=Na, K or NH4) respectively, whereas the complex of Fe2(OH)3(NO3)3 gives α-FeOOH or α-Fe2O3, depending on the temperature.
Isomerism of the Metal Complexes Containing Multidentate Ligands. III. Geometric and Optical Isomers of the Tris(2-methyl-1,2-propanediamine)cobalt(III) Ion
Authors: Kojima Masaaki , Yoshikawa Yuzo , Yamasaki Kazuo 
Published: July 2006

Abstract
The tris(2-methyl-1,2-propanediamine)cobalt(III) complex was prepared, and four possible isomers, geometrical and optical, were isolated by column chromatography on SP-Sephadex. Their configurations were assigned on the basis of the formation ratio and electronic, infrared, circular dichroism and PMR spectra: they were later confirmed by X-ray analysis.
The Analytical Application of Sulfur Analogues of β-Diketones. II. The Separation of Mercury(II), Cobalt(II), and Zinc(II) as Their STTA (1,1,1-Trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one) Complexes by Extraction Chromatography
Authors: Honjo Takaharu , Kiba Toshiyasu 
Published: July 2006

Abstract
The behavior of trace amounts of mercury(II), cobalt(II), and zinc(II) in liquid-liquid extraction have been investigated with 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one in cyclohexane, and the results applied to the separation of the three metals as their STTA complexes by extraction chromatography. A chromatographic column in which 10−3 M STTA in cyclohexane supported on Kel-F(poly-trifluorochloroethylene) powder was the stationary phase has been employed throughout this work. After the metal ions had been retained on the column by passing a sample solution of pH 5.5–6.0 through the column, the zinc(II) was eluted with an aqueous solution of pH 5.0 and then the mercury(II) was eluted with 1M hydrochloric acid. Last of all, since the cobalt had been caught so tightly on the column that it could not be removed even with concentrated hydrochloric acid, acetone was poured down the column in order to wash down all the organic phase together with the cobalt. The relation between the extraction chromatography and the liquid-liquid extraction in batches has been discussed with regard to the metal–STTA system under the same conditions.
Trinuclear Intermediates Isolated in the Reactions of Bis(acetylacetonato)-nickel(II) with Dry Hydrogen Bromide
Authors: Isobe Kiyoshi , Noda Kenichiro , Nakamura Yukio , Kawaguchi Shinichi 
Published: July 2006

Abstract
The reactions of bis(acetylacetonato)nickel(II) with restricted amounts of dry hydrogen bromide have been performed in appropriate mixtures of dichloromethane and petroleum ether at room temperature or lower in order to isolate the intermediary products, Ni3Br(acac)5, Ni3Br2(acac)4, and Ni3Br4(acac)2. The essentially octahedral trinuclear structure of Ni3Br(acac)5 was established on the basis of elemental analysis, by molecular-weight and magnetic-moment determinations, and by studying the electronic and IR spectra. Ni3Br2(acac)4 and Ni3Br4(acac)2 were characterized less satisfactorily because of their lower solubilities. The reactions of these mixed complexes with pyridine have also been examined; a new complex NiBr(acac)(py)3 was thus obtained in addition to the known compound, Ni(acac)2(py)2.
Dielectric Relaxation and Molecular Structure. III. Dielectric Relaxation Study of Some Anilines in Benzene Solutions at Different Temperatures
Authors: Vij J K , Krishan Iqbal , Srivastava K K 
Published: July 2006

Abstract
Measurements of relative permittivity at 1 MHz and at 9.46 GHz, the refractive index for the Sodium D-line, have been made for (a) N,N-dimethylaniline, (b) N,N-diethylaniline, (c) o-chloroaniline, (d) m-chloroaniline and (e) p-chloroaniline at temperatures of 15, 25, 35, and 45°C in dilute solutions of benzene. Dielectric relaxation times τ(1) and τ(2) have been calculated by the method recently suggested by Higasi, Koga, and Nakamura in terms of the slopes a0, a′, a″, and aD. It is remarked that τ(2) at the experimental frequency of 9.46 GHz leads to τ1 the relaxation time for overall rotation, whereas τ(1) becomes an explicit function of τ1 and τ2- These determinations suggest the presence of both molecular and intramolecular rotations in the molecules. The results for τ(2) show a systematic decrease with increase in temperature whereas for τ(1) there seems to be no observable trend. The enthalpy and entropy of activation for molecular dielectric relaxation process has been determined. The enthalpy of activation for (a) and (b) is of the same order of magnitude (i.e., 3 kcal/mol), and the same is true for the case of (d) and (e) (1.8 kcal/mol) but 6.8 kcal/mol for (c). It appears that in o-chloroaniline, there is a finite probability of H–Cl bond formation between one of the amino hydrogens and the neighbouring chlorine atom.
Pyrolysis-Gas Chromatographic Studies of Ionically-chlorinated Poly-α-methylstyrenes
Authors: Okumoto Tadaoki , Takeuchi Tsugio 
Published: July 2006

Abstract
The microstructure of ionically-chlorinated poly-α-methylstyrene with or without a catalyst and the distribution of chlorine in the aromatic nucleus of the polymers were studied by means of pyrolysis-gas chromatography. The degradation products, such as α-methylstyrene, p-chloro-α-methylstyrene, and 3,4-dichloro-α-methylstyrene, gave good information about substitution reactions on the aromatic nucleus in original poly-α-methylstyrene. The differences between two series of ionically-chlorinated poly-α-methylstyrene were also discussed on the basis of yield of α-methylstyrene and p-chloro-α-methylstyrene.
Solvolysis of Organic Phosphates. VIII. γ-Elimination in the Spontaneous Hydrolysis of 2-Chloro-3-pyridylmethyl Phosphate
Authors: Murakami Yukito , Sunamoto Junzo , Kanamoto Naomi 
Published: July 2006

Abstract
2-Chloro-3-pyridylmethyl phosphate was hydrolyzed in aqueous media. All runs were carried out in a pH range 1–3 where the reactive species are essentially of neutral and monoanion forms. The main reaction product was 3-hydroxymethyl-2-pyridone, the reaction following an apparent first-order kinetics with respect to both pyridone formation and liberation of inorganic phosphate. The hydrolytic elimination of the 2-chlorine atom was catalyzed to a great extent by the phosphate group. The dephosphorylation was effected by the presence of the 2-chlorine atom as well. The hydrolysis of the neutral phosphate species, which is in general inert to hydrolysis, was much accelerated in the present hydrolysis. A plausible mechanism was presented in terms of the concerted elimination of both 2-chlorine atom and phosphate moiety by their mutual catalytic participation. Besides the main reaction process, a normal hydrolysis affording 2-chloro-3-pyridylmethanol was also detected to proceed to a minor extent.
Oxygen-18 Scrambling Reaction of Aroyl Alkyl Carbonates
Authors: Oae Shigeru , Uchida Yuzuru , Fujimori Ken , Kozuka Seizi 
Published: July 2006

Abstract
Specifically 18O-labeled p-substituted benzoyl cyclohexyl carbonates (1) were prepared and heated at 45, 70 and 75°C, and novel stepwise oxygen scrambling was found to take place in 1. On being heated at 45°C, the carbonic carbonyl oxygen atom and the oxygen atom sandwiched between the two carbonyl carbon atoms of 1 were found to scramble. The 18O-scrambling among the above two and carboxylic carbonyl oxygen atoms of 1 was found to take place at 70 or 75°C. A good first order kinetic dependence was observed for the first step of the scrambling at 45°C but no substituent effect. An intramolecular mechanism involving two steps of equilibration is proposed.
Poly(vinyl alcohol) with Pending 5-Substituted Uracils
Authors: Seita Toru , Kinoshita Masayoshi , Imoto Minoru 
Published: July 2006

Abstract
5-Chloro-, bromo-, iodo-, N-ethylamino-, and N,N′-diethylamino-1-[(2′-dihydrogenphosphato)-ethyl]-uracil were synthesized from 1-(2′-hydroxyethyl)-uracil through the combination of halogenation, phosphorylation, and subsequent amination. These compounds were coupled with poly (vinyl alcohol) using N,N′-dicyclohexylcarbodiimide as a dehydrating agent to give polymers having 5-substituted uracils as pending groups.
Studies of Azo Colors. XI. The Diazo-coupling Reaction of Pyrroles
Authors: Mitsumura Kazuo , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
Kinetic studies have been made of the coupling reaction of several diazonium salts with pyrrole, N-methylpyrrole, and N-ethoxycarbonylpyrrole. In the case of pyrrole, it was found, from the dependence of the apparent rate constant on the pH values, that the undissociated pyrrole reacted with diazonium salts in the pH range from 4.7 to 8.2, whereas in the pH region higher than 10.0 the reactive species was the conjugate base of pyrrole. The reactivity of the pyrrole anion was higher by a factor of 8 powers of ten than that of the undissociated pyrrole. The effects of the substituents of diazonium salts on the reaction rates were also investigated. The ρ-values (4.3–4.6) obtained in the Hammett plots were practically the same as those of diazo-coupling reactions which involve ordinary aromatic amines as coupling components.
The Nickel-catalyzed Cyclodimerization of Butadiene. The Synthesis of 2-Methylenevinylcyclopentane and the Isomerization of 1,3,7-Octatriene
Authors: Kiji Jitsuo , Yamamoto Kazuyoshi , Mitani Shin-ichi , Yoshikawa Susumu , Furukawa Junji 
Published: July 2006

Abstract
A catalyst system of NiX2(R3P)2–NaBH4 or –R′ONa (X=halogen, R and R′=alkyl) was found to yield 2-methylenevinylcyclopentane (MVCP) and n-octatrienes (OT), depending on the amount of NaBH4 or R′ONa, which act as a reducing agent for the nickel halide. Less than an equimolar amount of the reducing agent provides a catalyst for MVCP, whereas an excess amount provides that for n-octatrienes. In the latter case, the nickel halide is reduced to zero-valent nickel, which then reacts with hydrogen halide to give a catalyst for MVCP again. The catalyst (&lt;2:1 ratio of reducing agent: Ni) was also effective in the isomerization of 1,3,7-octatriene to MVP.
Solvolysis of cis- and trans-4-t-Butylcyclohexyl Tosylates in N-Methylacetamide. Rates and Products Distribution
Authors: Saitô Seiki , Yabuki Tatsumi , Moriwake Toshio , Okamoto Kunio 
Published: July 2006

Abstract
Solvolysis of cis- and trans-4-t-butylcyclohexyl tosylates (RX) in wet N-methylacetamide (H2O content: 0.06–0.94 wt%) was carried out to give olefins (77–93%), 4- and 3-t-butylcyclohexyl acetates (ROAc) (6–22%), and 4- and 3-t-butylcyclohexanols (ROH) (2–4%). In N-methylacetamide with water (0.06%, wt) trans-4-RX gave cis-4-ROAc containing 18% trans-4-ROAc whereas cis-4-RX yielded trans-4-ROAc containing only 3% of cis-4-ROAc. In the course of solvolysis (75% completion) trans-4-RX was isomerized to cis-4-RX (5.9%), whereas cis-4-RX gave only 0.3% trans-4-RX. These results are characteristic of solvolysis in this amide solvent when compared with those in other hydroxylic solvents. Stereochemical results obtained from the present studies on the solvolysis in N-methylacetamide can not be explained by the hypothetical hydrogen-bridged carbonium ion intermediate proposed for the solvolysis of cis-4-RX. The nature of N-methylacetamide as a solvolytic solvent is discussed especially with regard to the effect of its polymeric structure on the steric course of solvolysis.
Synthesis and Reactions of α-Bromoaroylacetarylamides
Authors: Shawali Ahmad S , Ali Mohammed I , Fahmi Abdelgawad A 
Published: July 2006

Abstract
Benzoylacetanilide and fourteen of its substituted derivatives were brominated to give α-bromobenzoylacetanilides (I). The spectral data of I indicate that they exist mainly in the keto form. Reaction of I with phenylhydrazine yielded 4-phenylazo-1,3-diaryl-2-pyrazolin-5-ones (IV). Treatment of I with thiourea and thioacetamide gave 2-amino-4-arylthiazole-5-carboxanilides (XII) and 2-methyl-4-arylthiazole-5-carboxanilides (XIII), respectively. With excess of concentrated sulfuric acid or polyphosphoric acid, α-bromobenzoylacetanilides (I) were converted into 3-bromo-4-aryl-2-quinolones (XVI). Structural assignments were based on the elemental and spectral analyses.
Synthesis and Halochromism of 4- and 6-Styryl-2-aminotropones
Authors: Imafuku Kimiaki , Matsumura Hisashi 
Published: July 2006

Abstract
The methylation of 4-styryltropolones with diazomethane afforded two isomers, 2-methoxy-4-styryltropones and 2-methoxy-6-styryltropones. Their reactions with ammonia gave the corresponding 2-amino-4-styryltropones and 2-amino-6-styryltropones, respectively, by normal nucleophilic substitution. Infrared and ultraviolet absorption spectra were measured. The halochromism of 2-aminotropones was also examined, the halochromic shifts being found to be linearly correlated with the Hammett substituent constants.
Peptide Synthesis via N-Acylated Aziridinone. I. The Synthesis of 3-Substituted-1-benzyloxycarbonylaziridin-2-ones and Related Compounds
Authors: Miyoshi Muneji 
Published: July 2006

Abstract
Optically-active 3-substituted-1-benzyloxycarbonylaziridin-2-ones were synthesized from the corresponding benzyloxycarbonyl l-amino acids by the use of a dehydrating agent, such as phosgene, thionyl chloride, or phosphorus oxychloride. The reaction was carried out in THF at −20–−30°C using triethylamine to neutralize the reaction solution exactly. Among the other N-protecting groups used in peptide chemistry, p-bromobenzyloxycarbonyl and p-chlorobenzyloxycarbonyl amino acids also gave the corresponding aziridinones quantitatively. Some of these N-acylated aziridinones were obtained in the crystalline form. A reaction mechanism was also described.
The Molecular and Crystal Structure of the Cyclic Pentamer of Formaldehyde, 1,3,5,7,9-Pentoxecane
Authors: Chatani Yozo , Kitahama Katsuki 
Published: July 2006

Abstract
The crystal structure of the cyclic pentamer of formaldehyde, 1,3,5,7,9-pentoxecane, has been determined by the X-ray diffraction method. The unit cell is orthorhombic, with a=8.154 Å, b=10.673 Å, c=7.666 Å. The space group is Pbcn, and there are four molecules per unit cell. The structure was refined by the blockdiagonal least-squares method to a final discrepancy factor, R, of 0.049, using 712 reflections observed with an automatic four-circle single-crystal diffractometer. The molecules in the crystals are ten-membered rings with an exact C2–2 symmetry; the torsion angles of the five independent C–O bonds are 72.9°, −118.7°, 84.2°, −123.4°, and 69.8°, and the two halves of the molecule are related by a twofold rotation axis. The averaged C–O bond length is 1.410 Å, and the averaged C–O–C and O–C–O bond angles are 115.6° and 111.8° respectively. The close intramolecular H···H distances are 2.17 Å and 2.20 Å.
A New Method for the Precise Measurement of the Polarographic Current and Its Application in Digital Polarography
Authors: Sakurai Sadato , Shirai Hideko , Niki Eiji 
Published: July 2006

Abstract
In order to increase polarographic precision and sensitivity, the oscillopolarographic current was digitized and stored in a 100-channel pulse-height analyzer (PHA) operated in the multi-sealer mode (MS mode). An oscillopolarograph which could sweep the DC potential rapidly was combined with the PHA. The digitized oscillopolarographic current was repeatedly stored in the PHA, so that the statistical noise was reduced and the signal-to-noise ratio of the oscillopolarographic current was increased. Also, the drift due to the change in the experimental conditions was removed effectively by shortening the measurement time. Therefore, precision was efficiently improved by means of accumulation. The relative deviation was 0.25% at the concentration of the 5×10−7 M cadmium ion. As an example of the application, trace amounts of copper, lead, and cadimum in 99.99% indium metal were analyzed.