bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidation Reactions of 2,4,6-Tri-t-butylaniline
Authors: Okazaki Renji , Hosogai Takeo , Hashimoto Masayoshi , Inamoto Naoki 
Published: July 2006

Abstract
Oxidation reactions of 2,4,6-tri-t-butylaniline with lead tetraacetate (LTA), lead tetrabenzoate (LTB), peroxybenzoic acid (PBA) and benzoyl peroxide (BPO) were studied and mechanisms of these reactions were briefly discussed. In the reaction with LTA, 4-acetoxy-1-imino-2,4,6-tri-t-butyl-2,5-cyclohexadiene (I), 2-acetamido-3,5-di-t-butylphenol (II) and 2-acetylimino-3,5-di-t-butyl-3,5-cyclohexadienone(III) were produced. Oxidation with LTB gave 4-benzoyloxy-1-imino-2,4,6-tri-t-butyl-2,5-cyclohexadiene (VI, major product) and 2-benzamido-3,5-di-t-butylphenol (VII). The reaction products with PBA were 2,4,6-tri-t-butylnitrosobenzene (VIII) and VII. In addition to the last two compounds, VI and 2,2′,4,4′,6,6′-hexa-t-butylazobenzene (XI) were obtained in the case of BPO.
Triazene Rearrangement. III. A Kinetic Study of the Rearrangement of N-Methyldiaryltriazenes
Authors: Yamada Takashi 
Published: July 2006

Abstract
The rate constants of the hydrochloric acid-catalyzed rearrangement of N-methyldiaryltriazenes were determined in 95% aqueous ethanol in the presence of N-methylaniline. Electrondonating substituents on the diazo-part in triazene promoted the rearrangement. A Hammett plot of the rate constants gave a good straight line. The negative ρ-value (−3.63 at 30.0°C) and the large positive values of the entropy of activation suggested that the rate-determining step in this rearrangement is the dissociation of protonated triazene; this is in contrast with the case of the Friswell-Green mechanism. This theory was suppoted by such a solvent effect as that the rate decreased a little as the polarity of the solvent increased. The kinetic behavior of triazenes in the absence of N-methylaniline, and the incorporation of N-methyl-o-toluidine into the product in the rearrangement of 1-p-chlorophenyl-3-methyl-3-phenyltriazene (Id), were also discussed in connection with the above mechanism.
Structure of Vinylacetylene Determined by Electron Diffraction and Spectroscopy
Authors: Fukuyama Tsutomu , Kuchitsu Kozo , Morino Yonezo 
Published: July 2006

Abstract
The average structure of vinylacetylene has been determined by making combined use of the electron-diffraction intensities obtained in the present study and the rotational constants supplied by microwave spectroscopy. The two sorts of data have been found consistent to the uncertainties given below. With the molecular symmetry assumed to be Cs, the following parameters have been obtained in regard to the zero-point average structure: r(C–C)=1.4310±0.0034, r(C=C)=1.3416±0.0042, r(C≡C)=1.2086±0.0028, r(C–H)vinyl=1.087±0.010, r(C–H)ethynyl=1.062±0.018Å, ∠(C=C–C)=123.1±0.5°, ∠(C–C≡C)=177.9±1.2°, ∠(H–C=C)=120.6±1.5°, ∠(C≡C–H)=182.3±3.8°. There seems to be a significant difference between the C–C length of vinylacetylene and that of propynal. The result has been discussed in terms of the bond-order bondlength correlation.
π-Allylie Coordination of Ethyl Acetoacetate to Palladium(II)
Authors: Tezuka Yoshisato , Ogura Tetsuya , Kawaguchi Shinichi 
Published: July 2006

Abstract
The ethanolysis of diketene is accelerated by the addition of sodium tetrachloropalladate(II). Yellow crystals separated in the end of this reaction were identified as di-μ-chlorobis(π-1-ethoxycarbonyl-2-hydroxyallyl)dipalladium(II) on the ground of analytical data, molecular weight and infrared spectrum. The same complex was also prepared directly by the reaction of palladium(II) chloride with ethyl acetoacetate in water.
The Stability of Fused Rings in Metal Chelates. IV. Preparation and Relative Stability of Copper(II) Complexes with Tetradentate Schiff Base Ligands
Authors: Nakao Yasuo , Nonagase Naoki , Nakahara Akitsugu 
Published: July 2006

Abstract
Relative stability of sixteen aldehyde- and the corresponding ketone-Schiff base chelates has been investigated in terms of their decomposing temperature and half-wave potential against the reduction of copper(II) at the dropping mercury electrode. The previous conclusion, established for copper(II) tridentate Schiff base complexes, that Schiff base chelates of aldehydes are generally less stable than those of corresponding ketones has been proved to be valid also for copper(II) tetradentate Schiff base complexes if there is no serious steric hindrance in the Schiff base ligand. As a result of this investigation, six new copper(II) chelates were synthesized and characterized.
Synthesis of 1- and 2-Morpholinophenazine Derivatives
Authors: Endo Hideo , Tada Masao , Katagiri Ken 
Published: July 2006

Abstract
A number of new morpholinophenazines have been prepared by the reactions of various halogenophenazine derivatives with morpholine. It has been found that the replacement of the halogen atom of halogenophenazine-N-oxides with morpholine is accompanied by the removal of the oxide group and that no morpholinophenazine-N-oxides are formed in these reactions.
Studies of Aminosugars. XXI. The Total Synthesis of Kanamycin C
Authors: Umezawa Sumio , Koto Shinkiti , Tatsuta Kuniaki , Tsumura Takayuki 
Published: July 2006

Abstract
4-O-(3-O-Benzyl-2-carbobenzoxyamino-4,6-O-isopropylidene-2-deoxy-α-d-glucopyranosyl)-N,N′-dicarbobenzoxy-2-deoxystreptamine has been prepared from paromamine and condensed with 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-d-glucopyranosyl chloride by a modified Koenigs-Knorr reaction. The identity of the synthetic α,α-diglycoside with a substance of the same structure derived from natural kanamycin C was shown. Removal of the masking groups gave the product identical with natural kanamycin C.
Photochemistry of Acetanilide. III. The Secondary Processes in the Photochemical Reaction
Authors: Shizuka Haruo 
Published: July 2006

Abstract
The photochemical secondary processes of acetanilide have been studied. The photochemical reaction of p-methylacetanilide at 2537 Å did not produce the p-rearrangement product, but the o-rearrangement one. The quantum yields of the o-rearrangement and of the disappearance of p-methylacetanilide were 0.092 and 0.12 respectively. Comparing the quantum yields of acetanilide with those of p-methylacetanilide, the values of the quantum yields for the predissociation of the N–C bond, the back reaction, and the recombination ratio were estimated to be 0.25, 0.10, and 0.9 respectively. These results indicate that the recombination reaction between the pair radicals formed by the predissociation of the N–C bond occur efficiently in a solvent cage. The rate constants of the back reaction, the o-rearrangement, and the p-rearrangement were proportional to the odd π electron densities of the anilino radical. No intermediate was observed by the flash photolysis. The small dependence of the quantum yields of acetanilide on the temperature supports the predissociation mechanism previously described. On the basis of these studies, the mechanism of the photochemical reaction of acetanilide in the liquid phase has been proposed.
Infrared Spectra of Acylureas and NN′-Deuterated Acylureas
Authors: Uno Toyozo , Machida Katsunosuke , Hanai Kazuhiko , Saito Yutaka 
Published: July 2006

Abstract
The infrared spectra of seven monoacylureas and their NN′-deuterated compounds have been measured in the region between 3600 and 450 cm−1. A number of characteristic absorption bands of the –CONHCONH2 and –CONDCOND2 groups have been found and assigned by referring to the infrared spectra of related compounds and the isotopic frequency shifts. Partial deuteration by mixtures of water and heavy water has been made to distinguish the absorptions due to the NH and NH2 groups from each other. The features of infrared spectra of monoacylureas can be explained by regarding them as composite spectra of aliphatic imides and urea. From the effect of the alkyl frame-work vibrations for the imide III frequency, it is suggested that the RCONH– group of monoacylureas takes the trans conformation.
Polymerization of N-Vinylcarbazole in the Presence of β-Cyanoacrolein
Authors: Sumitomo Hiroshi , Takemura Ichiro 
Published: July 2006

Abstract
It was found that N-vinylcarbazole (VCZ) initiated the polymerization in the presence of β-cyanoacrolein (CAL) even in air at room temperature. The polymerization of VCZ induced by CAL was investigated in benzene at 60°C. Polymer formed was found to be VCZ homopolymer. The rate of polymerization attains to a maximum at the mole fraction of CAL of about 0.65 in the monomer mixture. The products obtained from the terpolymerization in the system of CAL-VCZ-Styrene in benzene at 60°C contain no CAL unit and exclusively consist of the VCZ component. The composition curve of the copolymer is contrasted with that of a radical initiated copolymer. In view of these results, as well as the Q-e values of both CAL and VCZ, it seems possible that the cationic polymerization of VCZ is induced by some donor-acceptor type interaction between VCZ and CAL.
Solvated Electron Formed in Water by the Silent Electric Discharge in Argon Atmosphere
Authors: Yokohata Akira 
Published: July 2006

Abstract
Based on radiation chemistry of water a study on the chemical changes resulting from the silent electric discharge of aqueous solution under argon atmosphere was made for the purpose of elucidating the nature of the reducing species formed. In the neutral aqueous ClCH2COOH system the effects of such additives as CH3OH and NO3− on the yield of Cl− and in the system containing NO3− the yield of NO2− were investigated. Moreover, in the alkaline aqueous K3Fe-(CN)6 system emphasis was placed on the yield of aquocomplex. In view of the non-dependence of the yield of Cl− on the concentration of additive NO3− and of the low yields of NO2− and Fe(CN)5OH23− produced, it was concluded that in the silent electric discharge the yield of solvated electrons which react with solutes in the bulk of water is very small (G\lesssim0.06). Reasons for the low yield of solvated electrons are briefly described.
Spectroscopy and Magnetic Properties of Nitrosylpentaamminechromium Salts
Authors: Kobayashi Hanako , Tsujikawa Ikuji , Mori Masayasu , Yamamoto Yoshihisa 
Published: July 2006

Abstract
Nitrosylpentaamminechromium chloride (brown), perchlorate (green) and other salts of different colors were studied by visible, IR and ESR spectroscopy and by magnetic susceptibility measurements. The easy shift of visible absorption bands caused by the replacement of outer anions which are responsible for the color difference, ripples observed in one of the absorption bands, g-values from ESR and a spin state 1/2 suggested by the susceptibility measurements are interpreted on the basis of a qualitative MO theory for metal nitrosyl complexes.
Geochemical Fractionation of Induced Radionuclides in Fresh Nuclear Debris through the Atmosphere—Np-239 and Co-60
Authors: Sotobayashi Takeshi , Suzuki Toshio , Koyama Seitaro 
Published: July 2006

Abstract
The atmospheric fractionation of induced radionuclides is discussed in some detail on the basis of results obtained by making a radiochemical analysis of fresh nuclear debris originating from recent Chinese nuclear test explosions. Among fresh nuclear debris particles collected at Niigata about 4000km downwind from the Chinese test site, the trend for the enrichment of 239Np was somewhat modified as compared with that derived from an averaged sample collected by a large-scale and high-altitude sampling procedure; more 239Np was present in smaller-size fallout particles. Furthermore, it was found, in rain-water samples collected after the third Chinese nuclear explosion, that the atomic ratio at time-zero of 60Co/95Zr increased with a decrease in the 95Zr-concentration in rain and vice versa. This suggests that the atmospheric fractionation of 60Co-rich particles from 95Zr-rich ones takes place during the travel of atomic clouds around the world.
Asymmetric Reactions. II. Anomalous Stereoselectivity of the Grignard Reaction with N-Benzyl-2,3-O-isopropylidene-d-glyceraldimine
Authors: Ohgo Yoshiaki , Yoshimura Juji , Sato Tetsuo 
Published: July 2006

Abstract
Stereoselectivity of the organomagnesium reaction with N-benzyl-2,3-O-isopropylidene-d-glyceraldimine was examined under various conditions (change of molarity, solvent, and composition ratio of reagents). The selectivity was not effected by the molarity of the reagents but by the solvent. When the substrate was treated with a mixture of various ratio of magnesium bromide and diphenylmagnesium, a remarkable effect of the ratio on the stereoselectivity was observed. Maximum ratio of erythro/threo was obtained at the point of equimolar mixture of magnesium bromide and diphenylmagnesium in ether. The structure of the transition intermediate was discussed.
Organic Syntheses by Means of Metal Complexes. III. Cobalt Carbonyl-catalyzed Carbonylation of β-Propiolactone
Authors: Mori Yoichi , Tsuji Jiro 
Published: July 2006

Abstract
It was found that the carbonylation of β-propiolactone can be carried out in the presence of dicobalt octacarbonyl. Butyrolactone and succinic acid were obtained by the reaction of β-propiolactone with carbon monoxide and hydrogen. Succinic anhydride was obtained by the reaction with carbon monoxide.
Nitroalkenylferrocene. II. The Condensation Reaction of Nitroolefins with Aromatic Carbonyl Compounds
Authors: Shiga Mikio , Kono Hiromichi , Motoyama Izumi , Hata Kazuo 
Published: July 2006

Abstract
The condensation reactions of β-ferrocenylnitroethylene (1), with various aromatic aldehydes in the presence of an excess of sodium methoxide were investigated. The main products of these reactions were ferrocenylnitroalkenols (2), which were obtained from precursory sodium salts by the acidification of the reaction mixture. Sodium nitroalkanolate (4) was postulated as an intermediate in these reactions. On the other hand, the reaction of 1 with acetophenone resulted in a different condensation, one giving 1-benzoyl-2-ferrocenyl-3-nitropropane (11) and 1-benzoyl-2-ferrocenylethylene (12).
The Photoconductivity of the Titanium Dioxide Crystal
Authors: Iida Takeaki , Nozaki Hiroshi 
Published: July 2006

Abstract
The photoconductivity of titanium dioxide (rutile type) synthesized by the flame-fusion method was studied. The photoconductivity spectra showed three peaks. The first is the maximum response around the edge of the fundamental absorption of rutile; the second is the peak at 630 mμ (1.98 eV), and the third is the broad-band spectra in the near infrared region of 1.0–1.9 μ. From the facts that Fe is found by chemical analysis to be a major impurity in rutile, that the peak at 630 mμ is enhanced by the increase in Fe concentration from 0.006 mol% to 0.02 mol%, and that the infrared quenching band of photoconductivity is observed at 1.23 μ (1.01 eV) in Fedoped rutile, it is concluded that this peak at 630 mμ results from the excitation of the electron from the Fe3+ level. The broad-band spectra at 1.0–1.9 μ are enhanced by the reduction and are decreased by the oxidation of the crystal, so these excitation spectra are ascribed to lattice defects originating from the non-stoichiometry of TiO2. These defects have much influence on the photoconductivity of rutile, i. e., on the relation between the photocurrent and the electrical applied field, and on the change the photocurrent versus the time.
The Synergistic Effect in Solvent Extraction. The Effect of Carboxylic Acid on the Solvent Extraction of Europium(III) with Benzoyltrifluoroacetone
Authors: Shigematsu Tsunenobu , Tabushi Masayuki , Matsui Masakazu , Honjyo Takaharu 
Published: July 2006

Abstract
The effects of carboxylic acids, such as formic, chloroacetic, acetic, propionic, butyric and caproic acid, on the extraction of europium with benzoyltrifluoroacetone were studied. The extraction is enhanced by the adduct formation between metal chelates and carboxylic acids in the organic phase, while it is hindered by the formation of metal-complex ions with anions of carboxylic acids in the aqueous phase. Caproic acid acts as an organic Lewis base and shows the synergism, but formic and chloroacetic acids have a masking effect. Acetic acid, propionic acid, and butyric acid behave both as synergists in the organic phase and as masking agents in the aqueous phase. Gaproic acid forms more stable adducts than does n-hexyl alcohol, and the composition of the chelate adduct is estimated to be Eu(BFA)3·2CH3(CH2)4COOH.
Determination of Niobium by Photon-Activation Analysis Based on Internal-Reference Method
Authors: Oka Yoshinaga , Pung Tong-Chuin , Saito Tatsuya 
Published: July 2006

Abstract
The internal-reference method proposed previously has been applied to the photon-activation analysis of niobium using molybdenum as the reference element. For the determination of niobium, 92mNb produced by the (γ,n) reaction was utilized and 95mNb or 96Nb activities coming from molybdenum by the (γ,p) processes were used as reference. A series of molybdenum and niobium mixtures with known compositions were irradiated by bremsstrahlung photons with a maximum energy of 17 MeV for an hour. After niobium activities were separated chemically, their γ-ray spectra were measured with a lithium-drifted germanium detector. A good proportionality was obtained between the activity ratio, RA0, and the weight ratio, RW. Niobium down to 5μg can be determined with a relative error within ±3% under the present experimental conditions.
The Hydrolysis of the Uranyl Ion in Heavy Water
Authors: Maeda Masunobu , Kakihana Hidetaka 
Published: July 2006

Abstract
The hydrolysis equilibria of the UO22+ ion in heavy water containing 3m NaClO4 as an ionic medium were studied at 25°C by potentiometric titrations, employing a technique of constant-current coulometry. The deuterium-ion concentration was measured by means of a glass electrode. The most probable hydrolysis scheme chosen in the range of the total uranyl concentration from 1 to 10mm was: (UO2)2(OD)22+−(UO2)3(OD)42+−(UO2)3(OD)5+; the respective stability constants were −log β2,2=6.80±0.02, −log β4,3=14.00±0.07, and −log β5,3=18.63±0.02. The above results reveal that the composition of the hydrolysis species in heavy water are generally the same as those in light water, while the values of the stability constants are smaller in heavy water than in light water.
On the Photochemical Hydrogen Shifts in Arylcycloheptatrienes
Authors: Tezuka Takahiro , Kimura Masaru , Sato Aiya , Mukai Toshio 
Published: July 2006

Abstract
Photochemically-induced hydrogen shifts in 7-(p-chlorophenyl), 7-phenyl, 7-(p-methoxyphenyl) and 7-p-tolylcycloheptatrienes (Ia—d) were studied. The possibility of hydrogen 1,7 and 1,3 shifts in these compounds was examined on both experimental and theoretical grounds. It was concluded that the hydrogen 1,7 shift is the only suprafacial hydrogen shift possible in the excited cycloheptatriene system. In this study all the isomers of p-chlorophenylcycloheptatriene were separated by applying the Diels-Alder reaction to the photo-reaction mixture; the method of preparing each of those isomers will also be described.
Syntheses and NMR Spectra of the Substituted Methylferrocenes
Authors: Sato Masaru , Koga Michinao , Motoyama Izumi , Hata Kazuo 
Published: July 2006

Abstract
Several 1′- and 2-substituted 1-methylferrocenes were prepared, and their NMR spectra were measured. From the consideration of the chemical shifts, the transmission coefficient of the electronic effect through the ferrocene nucleus was calculated to be 0.28. 1′-Substituted 1-acetylferrocenes were also prepared, and their NMR spectra were discussed in connection with those of methylferrocenes.
Synthesis of Corticotropin Peptides. XI Synthesis and Biological Properties of [1-β-Alanine]-ACTH(1-18)-Octadecapeptide Amide
Authors: Inouye Ken , Tanaka Akira , Otsuka Hideo 
Published: July 2006

Abstract
The synthesis is described of an octadecapeptide amide, β-alanyl-tyrosyl-seryl-methionyl-glutamylhistidyl-phenylalanyl-arginyl-tryptophyl-glycyl-lysyl-prolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin except for the amino end which has been substituted by a β-alanine for the serine in native hormone. The adrenalstimulating activities of the octadecapeptide amide are compared with those of the corresponding 1-serine or 1-glycine octadecapeptide amide to show that the 1-β-alanine peptide is remarkably more active than the latter when assayed by in vitro, subcutaneous and intamuscular approaches, and that the activities of the former are maintained for a longer period of time than those of the latter. The 1-β-alanine peptide as a lipotropic agent is also shown to be more active than the synthetic analogs and a native corticotropin on rat adipose tissue. The differences among these octadecapeptide analogs in the biological properties are discussed in terms of their susceptibility toward the action of aminopeptidase.
Proton Magnetic Resonance Studies on Specifically Deuterated Sucrose Acetates
Authors: Suami Tetsuo , Otake Toshiki , Ogawa Seiichiro , Shoji Tadao , Kato Naoyuki 
Published: July 2006

Abstract
In the proton magnetic resonance spectrum of octa-O-acetylsucrose, an individual acetoxy group signal was assigned by direct comparisons of the spectra of specifically deuterated octa-O-acetylsucroses and that of nondeuterated one. The structures of 2,3,6,3′,4′-penta-O-acetylsucrose and 2,3,4,3′,4′-penta-O-acetylsucrose were further confirmed definitively by the present studies.
The Reaction of Sulfenyl Chlorides with Thioethers. II. Kinetic Studies
Authors: Oki Michinori , Kobayashi Keiji 
Published: July 2006

Abstract
The rates of the reaction of methyl α-phenethyl sulfide with benzenesulfenyl chloride were measured by means of product analyses. It was found that the reaction was general-acid-catalyzed and autocatalyzed. The rate-determining step was suggested to be the formation of a sulfonium ion derived from the reactants. Mechanisms for the formations of the products are suggested.
The Reaction of Sulfenyl Chlorides with Thioethers. III. The Configuration and the Isomerization of cis- and trans-α-Methylthio-β-phenylthiostyrenes
Authors: Oki Michinori , Kobayashi Keiji 
Published: July 2006

Abstract
Various α-methylthio-β-arylthiostyrenes were prepared by the action of arenesulfenyl chloride on α-methylthiostyrene. The configuration of the stereoisomers of the styrene derivatives was determined by studying the nuclear Overhauser effect in the proton magnetic resonance. The relative stabilities of α-methylthio-β-phenylthiostyrene isomers were determined by equilibrating with the aid of hydrogen chloride at various temperatures.
Studies on Dithiocarbamates. XII. Kinetic Studies on the Hydrolysis of Mesoionic 4,5-Diphenyl-1,3,4-thiadiazole
Authors: Talukdar P B , Banerjee S , Chakraborty A 
Published: July 2006

Abstract
Kinetic studies of the compound given in the title were conducted in aqueous alcohols over a wide range of pH. The observed rate constants are dependent on the hydroxide-ion concentration as well as polarity of the medium. Hydrolytic decomposition is characterised by a small magnitude of entropy (ΔS*) and negative salt-effect. Mechanism consistent with these facts has been suggested.