bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Coexisting Minerals on Graphitization of Carbon. I. Heat Treatments of Carbon under 3 kbar in the Presence of Limestone
Authors: Noda Tokiti , Inagaki Michio , Hirano Shin-ichi , Amanuma Kiyoshi 
Published: July 2006

Abstract
The effect of the presence of limestone on the graphitization of carbon was investigated by the heat treatments of the carbon sample under the quasi-hydrostatic pressure of 3.2 kbar. The carbon sample used was a coke (PV-7) prepared by carbonization of polyvinylchloride up to 680°C. It was placed between two disks of limestone so as to make a sandwich-type specimen. The heat treatments were performed in a simple piston-cylinder type vessel at various temperatures of 800–1300°C for 20–240 min. Above 1000°C, the carbon specimens were obtained as caked tablets. The profiles of (002) diffraction line of these carbon tablets were found to be composite, consisting of a sharp component profile at 26.5° and a broad one at lower angle than 26.2°. The component GM corresponding to the sharp component profile seemed to have the graphite structure. The content of the component GM increased very rapidly with the increase in heat treatment temperatures above 1000°C. Phenomenally, the developement of the graphite structure seemed to be closely related to the recrystallization and the melting of coexisting limestone, but some chemical effects should not be excluded.
Spectrophotometric Study of Metal Chelates of Eriochrom Black T (BT). II. Solution Equilibria between BT and Lead(II)-Nitrilotriacetate (NTA) or Cadmium(II)-N′-(Hydroxyethyl)-ethylenediamine-N, N, N′-triacetate (EDTA-OH)
Authors: Kodama Mutsuo , Sasaki Chifumi 
Published: July 2006

Abstract
The solution equilibria between BT and lead(II)-NTA or cadmium(II)-EDTA-OH chelates were studied spectrophotometrically, and the composition and the stability constants of the BT chelates of these metal ions were determined. In the presence of an excess amount of NTA or EDTA-OH, lead(II) and cadmium(II) ions join with BT to form a chelate with a 1-to-1 composition. The magnitude of the stability constants (1013.19 and 1012.74 respectively, μ=0.30) can explain satisfactorily the well-known experimental fact that BT can be used as a metallochromic indicator in Pb(II)- and Cd(II)-EDTA titrations.
Studies of the Pinacol Rearrangement. IV. The Kinetics and Mechanism of the Rearrangement of meso- and dl-2,2′ Dimethoxybenzopinacol
Authors: Matsumoto Kiyoshi 
Published: July 2006

Abstract
The first-order rate constants of the perchloric acid-catalyzed rearrangements of the meso-and dl-2,2′-dimethoxybenzopinacols were measured in anhydrous acetic acid. A linear correlation of the logarithm of the first-order rate constants (logk) with Hammett acidity function (H0) was obtained in each case. The large positive values of the entropy of activation support the A-l mechanism, which is also supported by the linearities of logk with H0, suggesting that the classical carbonium ion is an intermediate in these processes. The migration aptitude of the meso-isomer decreases with time, while that of dl increases. On the basis of this information, the mechanism of the rearrangement was discussed.
Studies on Cow’s Urine. IV. Determination by Gas-liquid Chromatography of an Acidic Part Obtained from Cow’s Urine
Authors: Suemitsu Rikisaku , Fujita Shin-ichi , Mishima Yasuo , Yoshimura Mitsuo 
Published: July 2006

Abstract
An acidic part obtained from cow’s urine was examined by gas-liquid chromatography. As the major components of the acidic part, benzoic acid, phenylacetic acid, β-phenylpropionic acid, and derivatives in which hydroxyl or methoxyl groups are attached to, respectively, para-, ortho-, and 3,4-positions of the aromatic ring were identified. It is conceivable that these compounds were mainly metabolic products of the phenylalanine, tyrosine, and 3,4-dihydroxy-phenylalanine (DOPA). Moreover, a new metabolic pathway of phenylalanine and its derivatives was tentatively represented.
The Viscosities of Aqueous Solutions Containing Metal Complexes. I. Luteo-type Co(II) and Co(III) Complexes and Ethylenediaminetetraacetato Complexes
Authors: Yasuda Motoo 
Published: July 2006

Abstract
The viscosities of aqueous solutions containing cobalt complexes formed with ammonia, ethylenediamine (en), propylenediamine (pn), 2,2′-bipyridine (bip), 1, 10-phenanthroline (phen), and ethylenediaminetetraacetic acid (H4edta) were determined with a Cannon-Fenske capillary viscometer. Measurements were made in a Shibata viscosity bath maintained at 25±0.01°C. The Jones-Dole viscosity B-coefficients of Co(III) complex cations formed with NH3, en, pn, bip, and phen increase in that order. There is no significant difference between the B-coefficients of [Cobip3]3+ and [Cobip3]2+, or [Cophen3]3+ and [Cophen3]2+. On the other hand, a pronounced difference is found between the B-coefficients of [Coedta]− and [Coedta]2−. This might suggest that there is a marked difference in the structure of [Coedta]− and [Coedta]2− anions.
The Benzylation and Phenylation Reactions of Unsaturated Compounds Using Organo Monohalides and Polynuclear Iron Carbonyl
Authors: Rhee Ilsong , Mizuta Norio , Ryang Membo , Tsutsumi Shigeru 
Published: July 2006

Abstract
The reaction of iodobenzene and benzyl halides (Cl, Br and I) with Fe3(CO)12 (mole ratio; Fe3(CO)12/R–X=1/3) gave the corresponding symmetrical ketones (18–55.2%). The increasing order of the reactivity of the organo halides to Fe3(CO)12 was as follows: iodobenzene&lt;benzyl chloride&lt;benzyl bromide&lt;benzyl iodide. In the reaction of benzyl chloride with Fe3(CO)12, when two-thirds of the Fe3(CO)12 had been used, or moles equal to benzyl chloride, the yields of the ketones were increased to 87% (total yield). The same reaction in the presence of olefin produced benzylation or phenylation products of the olefin; for example, the reaction of benzyl iodide with Fe3(CO)12 in the presence of acrylonitrile (in tetrahydrofuran) gave 4-phenylbutyronitrile (30.2%) and 4-cyano-6-phenylhexanonitrile (10.0%). When olefin with a higher coordinating ability to iron carbonyl was used, the yields of the benzylated adducts of the olefin decreased, while when the more reactive organo halide was used, the yields increassed. Thus, it was postulated that organo halide reacted with Fe3(CO)12 to form the σ-complex, benzyl(or phenyl)iron carbonyl halide, as an intermediate to the benzylation (or phenylation) products. The benzylation and phenylation reactions proceeded smoothly in a polar solvent (dimethylformamide or ethanol) to give high yields. The benzylation of phenylacetylene did not occur in benzene, but in a polar solvent it proceeded, giving 1,3-diphenylpropane and -propene. The mechanistic aspects of these reactions are discussed below.
Mechanism of Asymmetric Reactions. II. Kinetical Resolution of Racemic Primary Amines by Means of Sulfonylation with (+)-Camphor-10-sulfonyl Chloride—Preferential Conservation of an Absolute Configuration in the Asymmetric Sulfonylation of Racemic Amines
Authors: Okamoto Kunio , Minami Etsuo , Shingu Haruo 
Published: July 2006

Abstract
α-Phenylethylamine (I), α,β-diphenylethylamine (II), α-(β-naphthyl)-ethylamine (III) α-(α-naphthyl)-benzylamine (IV), α-pipecoline (V), 2-aminobicyclo[2.2.2]octane (VI), and methylamine (VII) have been partially sulfonylated by (+)-camphor-10-sulfonyl chloride in benzene (or toluene); the optical rotations for the unsulfonylated amines, partially resolved, have been measured. Examination of absolute configurations for the amines indicates that the (R) enantiomers of these amines (I, II, V and VII, including neomenthylamine (VIII) and isomenthylamine (IX)) react faster than the respective (S) enantiomers, with exception of III. The rate for the sulfonylation of (−)-menthylamine with (+)-camphor-10-sulfonyl chloride have been determined in toluene at the temperatures ranging from −20 to −40°C; the rate ratio of the (+)-menthylamine to the (−)-amine has been estimated from the extent of the kinetical resolution of the (±)-menthylamine. Kinetical implication of the coincidence of the preferred absolute configurations has been discussed.
Desorbability of Chemisorbed Water on Metal Oxide Surfaces. I. Desorption Temperature of Chemisorbed Water on Hematite, Rutile and Zinc Oxide
Authors: Morimoto Tetsuo , Nagao Mahiko , Tokuda Fujiko 
Published: July 2006

Abstract
The desorbability of water molecules chemisorbed on the surfaces of metal oxides has been investigated in the cases of α-Fe2O3, TiO2 (rutile) and ZnO. Water vapor adsorption isotherms were determined on the samples treated at various temperatures in a vacuum of 10−5 Torr. The BET Vm-values of water adsorption were plotted against the temperature of the pretreatment. The curves obtained show a sharp increase at a moderate temperature which is varied by the nature of solid substance. This fact makes us conclude that, at this temperature, the chemisorbed water on oxide surfaces starts to be removed. The variation in the desorption temperature due to the nature of metal oxide is considered to come from the magnitudes of the bonding force of the surface hydroxyl groups to the surface metal atoms on each solid.
The Crystal and Molecular Structure of 1,1′-Bis(pentamethyldisilanyl)-ferrocene,(π-C5H4Si(CH3)2Si(CH3)3)2Fe)
Authors: Hirotsu Ken , Higuchi Taiichi , Shimada Akira 
Published: July 2006

Abstract
Crystals of 1,1′-bis(pentamethyldisilanyl)ferrocene, (π-C5H4Si(CH3)2Si(CH3)3)2Fe, are monoclinic, with a=6.84, b=30.87, c=12.67 Å and β=96.80°. The space group is P21/n and there are four molecules in a unit cell. The structure was solved by Patterson and minimum functions, and further refined by Fourier and difference syntheses, and finally by a least-squares method. The final R value is 14.4% for 883 observed reflections. The two cyclopentadienyl rings are planar, approximately parallel to each other, separated by 3.28Å and deviated by about 6° from the fully eclipsed configuration. The molecular configuration is gauche with respect to the two side-chains. The mean values of the bond distances are found to be Fe–C(cyclopentadienyl rings)=2.05, C–C=1.45, C(cyclopentadienyl rings)–Si=1.87, C(methyl groups)–Si=1.90 and Si–Si=2.34 Å. All intermolecular separations correspond to the normal van der Waals interactions.
An Experimental Study on the Faradaic Impedance of an Electrode Process with a Preceding Chemical Reaction
Authors: Matsuda Kiyoshi , Tamamushi Reita 
Published: July 2006

Abstract
The frequency dependence of the faradaic impedance and its phase angle of an electrode process with a preceding chemical reaction was studied with the Cd(II)-EDTA system. The experimental results were analyzed by means of Smith’s equation, and the rate constant of the reaction, Cd2++HY3−→CdY2−+H+, was estimated to be equal to 2·3×109 l mol−1 sec−1 at the ionic strength of 0.5 and at 25°C. In connection with this study, the faradaic impedance behavior of simple electrode processes was re-examined with the Cd(II)-, Pb(II)-, and Zn(II)-KC1 systems.
Kinetics of Electron-transfer Reactions Involving Ethylenediaminetetra- acetatochromate(II) Ions as Reductants. I. Reactions with Some Isothiocyanatoammine Complexes of Chromium(III)
Authors: Ogino Hiroshi , Tanaka Nobuyuki 
Published: July 2006

Abstract
Kinetics of electron-transfer reactions of ethylenediaminetetraacetatochromate(II) ions with some isothiocyanatoammine complexes of chromium (III), Cr(NCS)n(NH3)6−n(3−n)+(n=0, 1,4 and 6) have been studied. The former ions are present in the forms of both CrII(H2O)edta2− and CrII(H2O)Hedta−, but the reaction of CrII(H2O)Hedta− with Cr(NCS)n(NH3)6−n(3−n)+ is not significant in the pH range from 3.6 to 5.3. Second-order rate constants (l mol−1sec−1) of the reactions between CrII(H2O)edta2− and Cr(NCS)n(NH3)6−n(3−n)+ at ionic strength 1.0 and 25°C are &lt;10−2 Cr(NH3)63+, 0.2 for CrNCS(NH3)52+, 2.3 for Cr(NCS)4(NH3)2−, and 28.2 for Cr(NCS)63−.
A Study of Unnatural Amino Acids and Their Peptides. III. The Syntheses of Dl-β-(2-Pyridyl)-α-alanine and Its Peptides
Authors: Watanabe Hiroshi , Kuwata Shigeru , Naoe Kenzo , Nishida Yoshiteru 
Published: July 2006

Abstract
Dl-β(2-Pyridyl)-α-alanine has been synthesized in a good yield by the condensation of α-picolyl chloride and diethyl acetamidomalonate and by the subsequent hydrolysis of the product. The N-carbobenzoxy derivative of this amino acid, quite different from 3-pyridylalanine reported by Griffith and Harwood, could easily be prepared in a good yield. Only the carbodiimide method and the N-bromosuccinimide method proved to be successful in bringing the N-carbobenzoxylated amino acid into a peptide-coupling reaction with an amine component. Other methods, i. e., the mixed anhydride method, the azide method and the p-nitrophenyl ester method, were unsuccessful. It is noteworthy that, in the former cases, the activation of the carboxyl group occurs in situ in the presence of an amine component. No difficulties were encountered in the coupling reaction of the alkyl ester of this amino acid with usual N-protected amino acids. The alkaline hydrolysis of the protected dipeptide ester afforded the N-protected peptide in a good yield. The catalytic hydrogenation could be used to remove the benzyl ester group as well as the carbobenzoxy group without any damage to the pyridine ring. Decarbobenzoxylation also proceeded smoothly with hydrogen bromide in acetic acid.
Synthetic Reactions by Complex Catalysts. IX. Reaction of Thiol with Isocyanide
Authors: Saegusa Takeo , Kobayashi Shiro , Hirota Kiwami , Okumura Yoshiharu , Ito Yoshihiko 
Published: July 2006

Abstract
The reaction of a thiol with an isocyanide proceeds in two directions. In the first reaction (course a), the carbon atom of isocyanide with lone-pair electrons is inserted into the sulfur-hydrogen bond of thiol to produce thioformimidate (I). In the second reaction (course b), isothio-cyanate (II) and the alkane (III) from the alkyl group of thiol are formed. The proportion of the participation of two reactions depends upon the alkyl group of thiol and upon the reaction conditions including whether or not a catalyst is employed. Primary thiol prefers course a to course b, whereas tertiary thiol prefers course b. In the reactions at 15°C, the Group IB and IIB metal compounds, e. g., copper compounds, catalyzed the course a reaction preferably. At higher temperatures, e. g. at 100°C, thiol reacts with isocyanide quite rapidly, even in the absence of a catalyst. However, the catalyst effect favoring course a is seen even in the high-temperature reactions. The mechanism of the reaction, especially course b, has been discussed. Syn-anti structures of thioformimidate were also studied by NMR.
Studies of Heteroaromaticity. IX. Stability and Reactivity of 5-Nitro-2-furyl Diazo Compounds
Authors: Sasaki Tadashi , Eguchi Shoji , Kojima Atsuyuki 
Published: July 2006

Abstract
(5-Nitro-2-furyl)diazomethane (2), 3-(5-nitro-2-furyl)diazopropene (4), and 1-(5-nitro-2-furyl)diazoethane (6) were prepared by the oxidation of the corresponding hydrazones with active manganese dioxide. The relative stabilities of these diazo compounds were then compared with p-nitrophenyldiazomethane in their ethanolic solutions and in their solid states by measuring their decomposition rates spectroscopically; it was found that the stability decreased in the following order:
2& 6\backsimeqp-nitrophenyldiazomethane&gt;2\backsimeq4 & & in ethanol
& p-nitrophenyldiazomethane&gt;2&gt;4&gt;6 & & in the solid state.
The reactivities of these diazo compounds were also investigated in the decomposition reactions; the thermal and photolytic decomposition of 2 afforded l,2-di(5-nitro-2-furyl)ethylene (7) in a low yield, but 4 cyclized readily to 3-(5-nitro-2-furyl)pyrazole (8) in a good yield and 6, to an azine (9) even upon standing at room temperature. 2 was treated with benzoic acid in ether to give 5-nitro-2-furfuryl benzoate (10) in a quantitative yield, and with triphenylphosphine in the same solvent to afford the triphenylphosphazine (13) in a 75% yield; this last substance liberated nitrogen very easily in the presence of cuprous ions to give the phosphonium ylid (14), one of the Wittig reagents. 14 was then considered as a possible starting material for preparing (5-nitro-2-furyl)ethylenic compounds. Similarly, 3-(5-nitro-2-furyl)acrolein triphenylphosphazine (17) was prepared from 4 and triphenylphosphine.
Photoreduction of Azoxybenzene to Azobenzene
Authors: Tanikaga Rikuhei 
Published: July 2006

Abstract
The photochemical reduction of azoxybenzene to azobenzene has been investigated. The direct irradiation of azoxybenzene leads to a rearrangement to 2-hydroxyazobenzene and to cis-trans isomerization, whereas the sensitized irradiation leads to a reduction to azobenzene in the presence of a sensitizer with a triplet excitation energy greater than ca. 62 kcal/mol. 2-Hydroxyazobenzene and cis-azoxybenzene seem to be formed from the excited singlet state of azoxybenzene, and azobenzene, from the excited triplet state. Even without a sensitizer, the irradiation of benzo[c]cinnoline N-oxide, which is incapable of undergoing rearrangement or isomerization, brings about a photochemical reduction, which is affected by a sensitizer or a quencher, and also by the hydrogen-donating ability of the solvent used (isopropanol&gt;ethanol&gt;cumene&gt;toluene). Acetone is yielded when isopropanol is used as the solvent. On the basis of these results, a mechanism in which benzo[c]cinnoline is formed from the excited triplet state of benzo[c]cinnoline N-oxide, followed by hydrogen abstraction from a solvent, is proposed.
Cationic Polymerization of Formaldehyde in Liquid Carbon Dioxide. IV. A Kinetic Study of the Polymerization in the Presence of Acetic Anhydride
Authors: Yokota Hisao , Kondo Masatsune , Kagiya Tsutomu , Fukui Kenichi 
Published: July 2006

Abstract
The influence of acetic anhydride on the polymerization of formaldehyde, which was carried out by means of initiation with an acidic catalyst in liquid carbon dioxode, was studied at 20 to 40°C. Acetic anhydride decreased the polymer yield and the degree of polymerization of the polymer resulting from the polymerization with acetic acid. Moreover, the over-all rate of polymerization with acetic acid in the presence of acetic anhydride deviated from a first-order equation with respect to the monomer concentration. On the other hand, the polymerization which was initiated by dichloroacetic acid was not affected by the presence of acetic anhydride. On the basis of a kinetical consideration, it can be said that the termination which was proportional to the square of the concentration of the initiating species was caused by the presence of acetic anhydride in the polymerization with acetic acid. The rate constants and the activation energies of the elementary processes were estimated, and a rate equation satisfying the experimental results was presented.
Initiation and Propagation in the Copolymerization of N-Phenylethylenimine with β-Propiolactone
Authors: Kagiya Tsutomu , Kondo Tomizo , Fukui Kenichi 
Published: July 2006

Abstract
In the copolymerization of N-phenylethylenimine with β-propiolactone, the mechanisms of the initiation and propagation reactions were investigated. The rate of the copolymerization was markedly increased by the addition of propionic acid. When a mixture of triethylamine and propionic acid was used as additive, the rate decreased with an increase in the amount of triethylamine, while with an equimolar mixture the rate was almost equal to that without any catalyst. No polymer was obtained with an excess of triethylamine. With Brönsted acid, the composition of the copolymer was independent of the concentration of the catalyst, but it varied with the pKa value. The monomer reactivity ratio of N-phenylethylenimine increased with a decrease in the pKa value. While that of β-propiolactone decreased.
Ring-opening Polymerization of the Macrocyclic Ester
Authors: Yoda Kentaro , Kimoto Kazuyuki 
Published: July 2006

Abstract
The ring-opening polymerization of cyclic bis(ethylene isophthalate) (I) was carried out in the presence of various metallic compounds as catalysts. Among the polycondensation catalysts for ethylene terephthalate, antimony and tin compounds were very effective in the ring-opening polymerization of I. On the other hand, titanium, zinc, calcium, and aluminum compounds did not show high catalytic activity. The polymerization of I proceeded even at temperatures below the melting point of I. As the melting point of the resulting poly(ethylene isophthalate) was much lower than the polymerization temperature, the reaction system gradually melted in consequence of the progress of the polymerization reaction.
Aluminum Silanolates Acid Strength and Polymerization Catalyst Activity
Authors: Saegusa Takeo , Ueshima Takashi , Kato Kunioki 
Published: July 2006

Abstract
Two aluminum silanolates, diethyl(trimethylsiloxy)aluminum (I) and tris(trimethylsiloxy)-aluminum (II), were compared with the corresponding aluminum alcoholates in terms of their acid strength and in their catalyst behavior in the polymerizations of cyclic ethers and vinyl ether. The reference aluminum alcoholates were diethylaluminum t-butoxide (III) and aluminum t-butoxide (IV). The Lewis acid strength was examined by means of two methods, the Hammett indicator method and the shift of the IR carbonyl band (ΔνC=O) of n-butyraldehyde. Four aluminum compounds, I–IV, were weaker Lewis acids than triethylaluminum; i.e., the replacement of the ethyl group of triethylaluminum with either a siloxy group or an alkoxy group brought about a decrease in the acid strength. The acid strength of I and II were demonstrated to be stronger than that of the reference alcoholates, III and IV. A difference in polymerization catalyst activity was also observed between aluminum silanolates and the reference alcoholates; it was reasonably explained by the difference in acid strength.
Copolymerization of N-Phenylethylenimine and β-Propiolactone
Authors: Kagiya Tsutomu , Kondo Tomizo , Narisawa Shizuo , Fukui Kenichi 
Published: July 2006

Abstract
The copolymerization of N-phenylethylenimine and β-propiolactone was carried out at 0°C in an acetonitrile solution. N-Phenylethylenimine and β-propiolactone copolymerized without any catalyst to give a powdery or a resinous polymer. From the results of a study of the infrared spectrum, X-ray diffraction, differential thermal analysis, and hydrolyses of the copolymer, it was concluded that the homopolymerization of neither monomer took place, and that the copolymer contained the ester structure of (Remark: Graphics omitted.)-in the main chain. The monomer reactivity ratios of N-phenylethylenimine (r1) and β-propiolactone (r2) were estimated to be r1=7.5 and r2=0.15.
Dynamic Mechanical Behaviour of Organic Molecular Crystals. II. Elastic Constants of Single-Crystal Anthracene
Authors: Danno Takaaki , Inokuchi Hiroo 
Published: July 2006

Abstract
The thirteen elastic constants, Cij, and the elastic compliances, sij, of monoclinic single-crystal anthracene were determined from sound velocities measured by the ultrasonic pulse method at room temperture. The observed elastic constants were C11=8.92, C12=4.63, C13=4.49, C15=−2.58, C22=13.8, C23=8.45, C25=−2.59, C33=17.0, C35=−2.88, C44=2.42, C46=1.14, C55=2.84 and C66=−3.16 (in units of 1010 dyn/cm2). The hydrostatic linear compressibilities, β, of the anthracene molecular crystal were then calculated from these elastic constants and compliances; the β along [100] was 12.7×10−12 cm2/dyn, β[010]=4.41×10−12 cm2/dyn, and β[001]=3.59×10−12 cm2/dyn.