bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical and Optical Behaviour of Tetrathionaphthacene at High Pressures
Authors: Shirotani Ichimin , Kawada Kaoru , Inokuchi Hiroo 
Published: July 2006

Abstract
The temperature dependence of the electrical resistance and the absorption spectra for tetrathionaphthacene (T.T.N.) have been studied at high pressure. It has been found that the intrinsic conduction level, which does not correspond to the observed optical transition, is located about 2 eV above the valence band. The red shift of absorption peaks with the pressure was much smaller than the contraction of the intrinsic band gap. The existence of the intrinsic conduction level is supported by the fact that the minimum of the photoemission yield arising from electron-pair production is located about 2 eV above the threshold point. The band gap of 0.4–0.62 eV previously observed seems to correspond to an acceptor level formed by chemical impurities.
Surface Properties of the System SiO2-Al2O3 prepared by the Hydrolysis of Metal Alkoxides
Authors: Murayama Hiroyoshi , Meguro Kenjiro 
Published: July 2006

Abstract
The mixtures of aluminum s-butoxide and silicon ethoxide in different molar ratio were hydrolyzed in aqueous alcohol. The precipitates were dried, and the growth and transformation of the crystals at calcination were estimated by X-ray diffractometry. The surface properties of the oxide powder were studied by means of the heats of immersion and the adsorption of nitrogen, water vapor and ammonia. The samples calcined at 500°C have surface areas 260–600 m2/g. Heats of immersion and surface hydrophilicity with respect to the composition, from pure silica gel to pure alumina, have a fairly good resemblance to each other, but this is not found between the heats of immersion and surface acidity.
Structural Studies of Antimony Tribromide and Its Molecular Complex with Benzene by Means of the 81Br Nuclear Quadrupole Resonance
Authors: Okuda Tsutomu , Terao Hiromitsu , Ege Osamu , Negita Hisao 
Published: July 2006

Abstract
The structures of α-antimony tribromide and its molecular complex with benzene 2SbBr3·C6H6 were investigated by studying the Zeeman effect on the nuclear quadrupole resonance (NQR) due to 81Br at room temperature. The bond angles, ∠Br-Sb-Br, of α-antimony tribromide in its solid state were found to be 94°14±4′, 94°31′±8′, and 98°27′±7′. The polar angles specifing the directions of the Sb-Br bonds with respect to the orthorhombic crystal axes are (60°0′±9′, 62°13′±7′), (59°10′±7′, −54°35′±8′), and (57°39′±17′, 180°0′±3′). These values are consistent with those of the X-ray analysis by Gushen et al. within about 1°. The asymmetry parameters at the three bromine atoms were 0.068±0.002, 0.049±0.002, and 0.080±0.004. On the other hand, the bond angles, ∠Br-Sb-Br, of the SbBr3 molecule in the complex 2SbBr3·C6H6 were found to be 92°24′±11′, 97°7′±14′, and 97°40′±6′. The crystal has a monoclinic symmetry, and the three Sb-Br bonds have directions making angles of 29°4′±21′, 76°26′±9′ and 63°33′±11′ relative to the b-axis. The asymmetry parameters at the three bromine atoms in the complex were 0.169±0.001, 0.063±0.002, and 0.094±0.002. The largest value of the asymmetry parameters seems to be the result mostly of the intermolecular bonding. From the coupling constants, the Sb-Br bond characteristics in antimony tribromide and its molecular complex, 2SbBr3·C6H6, are considered to be almost the same.
Studies of the Liquid-Liquid Partition Systems. VII. The Solvent Extraction of Mercury(II) Chloride, Bromide, Iodide and Thiocyanate with Some Organic Solvents
Authors: Sekine Tatsuya , Ishii Teruhiko 
Published: July 2006

Abstract
The liquid-liquid distribution of mercury(II) has been determined when the organic phase was benzene, hexane containing tributylphosphate(TBP), methylisobutylketone(MIBK), or nitrobenzene, and when the aqueous phase was 0.5m sodium per chlorate containing chloride, bromide, iodide, or thiocyanate ions. The stability constants for the mercury(II) complexes in the aqueous phase and the distribution constants for the extractable complexes were determined by a graphic analysis of the distribution data, which were measured as a function of the ligand concentration. It was concluded that the stability constants determined from the present results agree almost entirely with the previous values and that the only extracted species into benzene and hexane containing TBP is the non-charged complex (HgX2, where X− is the ligand) in all cases, whereas those extracted into MIBK or nitrobenzene include not only the non-charged but also the charged species (HgX3− and sometimes HgX42−) except in the case of the chloride system. The distribution ratio in the hexane-TBP system was further determined by changing the TBP concentration in the hexane phase, and the equilibrium constants for the adduct formation between the HgX2 species and TBP molecules were determined. Finally, some discussion was made of the relation between the distribution behavior of the mercury(II) complexes and the natures of the ligands and the solvents.
Absorption Spectra of Gaseous Benzo[g,h,i]perylene and Coronene
Authors: Aihara Jun-ichi , Ohno Koichi , Inokuchi Hiroo 
Published: July 2006

Abstract
The gas-phase spectra of typical polycyclic aromatic hydrocarbons benzo[g,h,i]perylene and coronene, were measured. These data can be used as criteria for the solvent shifts and the molecular excitons.
Direct Determination of Charge Transfer Energy
Authors: Aihara Jun-ichi , Tsuda Motoyuki , Inokuchi Hiroo 
Published: July 2006

Abstract
The absorption spectrum of the gaseous anthracene - chloranil complex was measured. The Coulomb energy contributing to the charge-transfer transition was determined to be 3.03 eV. The polarization energy for the transition was 0.17 eV in an n-heptane solution.
Ion-Solvent Interaction of Tetraalkylammonium and Some Common Ions in N-Methylformamide from Viscosity Data
Authors: Rastogi Pushti Prakash 
Published: July 2006

Abstract
Solute-solvent interaction of tetraalkylammonium iodides (R4NI) and some common electrolytes has been studied in N-methylformamide (NMF) from the viscosity point of view. From the obtained results it has been concluded that common electrolytes like LiCl, KI, CsI are net structure promoters while R4NI salts are net structure breakers in this solvent.
Ionic Equilibria in Mixed Solvents. V. Intermediates of Polymerization of Aluminum Ion in a 0.2 Mole Fraction Dioxane-Water Mixture
Authors: Ohtaki Hitoshi 
Published: July 2006

Abstract
Formation of highly polymerized hydroxo-complexes of aluminum ions proceeded so slowly in a dioxane-water mixture that less polymerized intermediates were detected by means of the usual emf titration techniques. The titrations were performed at 25° in solutions of total aluminum concentrations of 0.00500, 0.0100, 0.0200, 0.0399, 0.0400 and 0.0798m in a 0.2 mol fraction (55.01 % w/w) dioxane-water mixture containing 3m LiClO4 as an ionic medium. The emf data obtained can be explained in terms of the formation Al2(OH)24+ (log*β2,2=−6.95±0.07) and Al2(OH)33+ (log*β3,2=−10.02±0.03) assuming equilibrium conditions. It was observed that these complexes proceed further slowly to form highly polymerized complexes.
Photon-Activation Analysis for Iodine by Using Cesium as the Internal-Reference Element
Authors: Tsai Hui-Tuh , Kato Toyoaki , Oka Yoshinaga 
Published: July 2006

Abstract
The internal-reference method proposed previously has been applied to the determination of iodine by photon-activation analysis, using cesium as the internal-reference element. The present method is based on the measurement of the 126I, 124I and 123I activities produced by the neutron-emitting reactions in iodine, and on the comparison of these activities with that of 130I coming from cesium by the (γ, 2pn) reaction. A lithium-drifted germanium diode with a sensitive volume of 36 cm3 was used as the detector. The yields of various photonuclear reactions in both elements have also been examined as a function of the bremsstrahlung maximum energies up to 65 MeV. A series of synthetic mixtures of iodine-cesium with known weight ratios has been used to check the sensitivity and the accuracy of this method. We found that we could determine amounts of iodine down to 0.2 μg under the present experimental conditions.
Alkoxysilanes. V. The Preparation of Polyalkyl(aryl) Silicates
Authors: Abe Yoshimoto , Takeuchi Takeo , Kijima Ichiro 
Published: July 2006

Abstract
Silicon-containing novel polymers, polyalkyl(aryl) silicates (Remark: Graphics omitted.) and (Remark: Graphics omitted.), were prepared by the reaction of diaminosilanes with aliphatic or aromatic diols. The products were a white powder (fused at about 300°C), a highly viscous liquid, or a glassy solid; these products were soluble in common organic solvents, but insoluble in methanol. The results of the molecular-weight determination by the vapour-pressure method indicated that some of polymers had a molecular weight of 5000 or 6000. A study of the thermal stability of the polymers by means of TGA and DTA analysis made clear that the polymers with the aryloxy group in the molecular main chain were remarkably more stable than those with the alkoxy group. The former indicated a weight loss of about 50% at 350–400°C. An investigation of the TGA curve and thermal decomposition products allowed us to discuss the probable process for the degradation of the polymers. The reaction of the diaminosilanes with 1,4-butanediol afforded distillable products rather than the expected polymers; these products were identified as being cyclic alkoxysilanes.
Synthese der Epiminozucker
Authors: Ichimura Kunihiro 
Published: July 2006

Abstract
Two-step conversion of aldehydes to 2-monosubstituted aziridines has been extended to sugar derivatives. Treating O,O′-isopropylidene-d-glyceraldehyde with benzenesulfonyl chloride and sodium cyanide, 2-benzenesulfonyloxy-3,4-isopropylidenedioxybutyronitrile is obtained as a mixture of the diastereomers in a good yield, and is converted to the corresponding ketalaziridine, 2-(1,2-isopropylidenedioxyethyl)aziridine, by the reduction with lithium aluminum hydride. When the partially racemized isopropylideneglyceraldehyde is used, the diastereomers obtained are successfully separated by the fractional recrystallization. Each diastereomeric α-sulfonyloxynitrile is reduced by lithium aluminum hydride to afford the ketalaziridine, which is p-nitrobenzoylated and rearranged to the derivative of 1,3,4-trihydroxy-2-amino-butane by means of sodium iodide. Analogously, 3-O-benzyl-1,2-O-isopropylidene-α-d-glucopentodialdo-1,4-furanose was converted to two urononitriles, 3-O-benzyl-5-O-benzenesulfonyl-1,2-O-isopropylidene-α-d-gluco-furanurononitrile and the epimeric β-l-idofuranurononitrile. The reduction of the former yielded 5,6-epimino-5,6-dideoxy-β-l-idofuranose.
Studies of the Thiocarbonyl Compounds. I. Syntheses and Thermal Rearrangement of O,S-Diaryl Dithiocarbonates
Authors: Araki Yoshiaki 
Published: July 2006

Abstract
Various O,S-diaryl dithiocarbonates with the general formula of p-X–C6H4–S–C(=S)–O–C6H4–Y-p (I) were prepared. When these substances were kept at an elevated temperature, they rearranged smoothly to S,S-diaryl dithiocarbonates of this general formula: p-X–C6H4–S–C(=O)–S–C6H4-Y-p (II). Kinetic studies showed that the rearrangement followed fairly good first-order kinetics. The rate constants in diphenyl ether at 200°C increased in the order: Y=OCH3&lt;CH3&lt;H&lt;Cl&lt;COCH3&lt;CN&lt;NO2. The entropies of activation were negative, and no crossover products were obtained. A four-membered cyclic structure can be suggested as the transition state for this rearrangement.
Bromodenitrogenation of N2-Benzoylarginine Ethyl Ester with N-Bromosuccinimide
Authors: Anzai Kentaro 
Published: July 2006

Abstract
N 2-benzoylarginine ethyl ester (II) reacted with N-bromosuccinimide at pH’s above 7 to yield, as the main product, N2-benzoyl-N5-cyanoornithine ethyl ester (VII), as well as N3,N6-bis(4-benzamido-4-ethoxycarbonylbutyl)s-tetrazine-3,6-diimine (VIII), N,N′-di(4-benzamido-4-ethoxycarbonylbutyl)urea (IX), and N2-benzoylcitrulline ethyl ester (X) as minor products. On acid hydrolysis, VII afforded the following amino acids: ornithine (III), citrulline (IV), N6-[(4-amino-4-carboxybutyl)-carbamoyl]arginine (V), and N,N′-di(4-amino-4-carboxybutyl)urea (VI). The mechanism of these reactions was also discussed.
Stereochemical Studies of Monoterpene Compounds. VIII. The Stereochemistry of Dihydro-β-campholenolactone and 1,2-Campholide
Authors: Hirata Toshifumi , Suga Takayuki , Matsuura Tamon 
Published: July 2006

Abstract
The stereochemistry of (+)-dihydro-β-campholenolactone (II) and (−)-1,2-campholide (III) was clarified to be Ila and IVc, respectively, by a combination of nuclear magnetic resonance, optical rotatory dispersion and circular dichroism measurements.
Alkylation of Sodium Dithionite
Authors: Matsuo Kuniko , Kobayashi Michio , Minato Hiroshi 
Published: July 2006

Abstract
Reaction between sodium dithionite and triethyloxonium fluoborate under nitrogen yielded an unstable oil capable of absorbing oxygen. When it was washed and distilled under reduced pressure, ethyl ethanesulfinate was obtained. The reaction between sodium dithionite and alkyl iodides in water or in DMSO yielded dialkyl sulfone. The reaction between sodium ethanesulfinate and triethyloxonium fluoborate in dichloromethane yielded an oily mixture which was 89% ethyl ethanesulfinate and 11% diethyl sulfone. The reaction of alkyl iodides with an excess of sodium dithionite yielded, besides a sulfone, sodium alkanesulfonate, not sodium alkanesulfinate. Mechanisms of these reactions were discussed.
The Adsorption of Polyvinyl Pyrrolidone on Silver Iodide Surfaces
Authors: Sugiura Masaaki 
Published: July 2006

Abstract
Adsorption isotherms for four kinds of polyvinyl pyrrolidone (PVP), having different molecular weights, on the sol particles and the powder of silver iodide at 25°C were obtained. Further, the adsorption of PVP on the sol particles was investigated by means of the electrophoresis method. All of the PVP materials give approximate adsorption isotherms of the Langmuir type, at least up to the PVP concentration of 0.4 g/l At higher concentrations, the amounts of PVP adsorbed gradually increase with the increase in the PVP concentration. The effect of the molecular weight on the PVP adsorption is not observed except for the lowest-molecular-weight material, which displays a lower adsorption. The tendency for the ζ-potential of the sol particles to increase with an increase in the PVP concentration almost coincides with that of the amount of PVP adsorbed.
Sound Velocity in Aqueous Non-Electrolyte Solutions in Relation to Water Structure
Authors: Nomoto Otohiko , Endo Harumi 
Published: July 2006

Abstract
An acoustic interferometer is employed to obtain the variation of sound velocity with concentration and temperature in hexamethylenetetramine (HMT), urea, thiourea, acetamide and N,N-dimethylformamide (DMF) and their aqueous solutions. The plot of velocity of aqueous solutions of these organic substances against temperature gives parabolic curves similar to one for pure water. In these curves, the maximum height of sound velocity is higher than that for pure water and the temperature at maximum point is lower than for water. The curves of sound velocity vs. concentration at various temperatures show values of maximum velocity at intermediate concentrations. The maximum value decreases with increasing temperature and finally disappears in some cases. Results show that the velocity dependency on temperature and concentration are qualitatively determined by the relative concentration of non-associated water to cluster. The sound velocity of acetamide and DMF is 1404.4 m/sec (65°C) and 1478.8 m/sec (20°C), respectively, and shows negative temperature coefficients of −2.68 m/sec/deg and −3.90 m/sec/deg, respectively.
Studies on Triplet Energy Transfer by Means of an Emission-Absorption Flash Technique. I. Reversible Energy Transfer between Xanthene Dyes and Anthracenes
Authors: Kikuchi Koichi , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
Choosing eosin and erythrosin as donor and anthracene and 9-methylanthracene as acceptor, we have kinetically investigated the triplet energy transfer process by flash technique involving emission measurement. In these systems the differences of T-levels of donor and acceptor are of the order of kT at most, and it was anticipated that a reversible energy transfer would occur. It has been established that it actually occurs in eosin-anthracene and erythrosin-anthracene, and very likely occurs in erythrosin-9-methylanthracene. Furthermore, it has been found that in the first two systems the energy transfer rate for the process, donor→acceptor is about half that for the process, acceptor→ donor. This means that the rate in the present systems is determined by some other factor than the triplet level. Discussions have been given on the model for energy transfer.
Methane Formation in the Radiolysis of Neopentane and Isooctane
Authors: Iida Shuichi , Yugeta Rei , Sato Shin 
Published: July 2006

Abstract
The formation of methane and hydrogen in the γ-radiolysis of neopentane and isooctane has been studied in the presence of an electron scavenger (N2O) and/or a radical scavenger (styrene). The G-value of nitrogen from neopentane solutions of nitrous oxide was found to be about twice the sum of the decrease in the G-values of methane and hydrogen. From isooctane solutions, G(N2) was more than three times the sum of the decrease in G(H2) and G(CH4). This can be interpreted on the assumption that a significant part of the neutralization of isooctane ions with electrons induces the fragmentation into C4-hydrocarbons. It was also found that a part of the methane formed (0.9 G in neopentane and 0.2 G in isooctane) was not produced by the reactions of ions or methyl radicals, but by a “molecular” process, probably the decomposition of the highly-excited states.
Photochromic Reaction of N-Nitroso-N-alkylaniline in the Aqueous Solution—A Contribution to the Photochemistry of Nitrosamine
Authors: Hoshino Mikio , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
It has been found that the aqueous solution of N-nitroso-N-methylaniline when irradiated by 253.7 nm shows photochromism. The unstable photoproduct reconverts to the original compound photochemically as well as thermally. The quantum yields for the forward and backward reaction are respectively 0.23 and 0.58. N-Nitroso-N-ethylaniline also reacts in the similar way. In the alcoholic solutions, different types of reaction occurred; in the absence of oxygen the reaction is mainly the formation of N-methylaniline. It has been suggested that the present photochromism is due to the cis-trans isomerization.
Spectrophotometric Determination of Mercury(II) by Solvent Extraction with Variamine Blue B
Authors: Tsubouchi Masahiro 
Published: July 2006

Abstract
A new rapid, sensitive and selective method is proposed for the spectrophotometric determination of a trace of mercury (II) by solvent extraction. The method is based on the formation of an ion-pair complex between the tribromo-mercury(II) complex anion and the dyestuff cation obtained by oxidation of variamine blue B. The optimum pH range for the color reaction is 2.5–4. The blue complex can be extracted into nitrobenzene and has a maximum absorption at 605 mμ in the organic solvent. Beer’s law holds in the range 3.2×10−6−2.2×10−5 m of mercury(II) in the aqueous layer before the extraction, with a molar absorptivity of 4.03×104 mol−1cm−1 l at 605 mμ. The color reaction is instantaneous and the complex remains stable 15 mintes in the nitrobenzene layer. Of the 22 cations and 11 anions examined, tin(II), tin(IV), antimony (III), iodide, cyanide, and thiocyanate showed serious interferences.
Nickel(II) Complexes of Ethylenediaminemonoacetic Acid (EDMA). The Preparation and Thermal Decomposition of Nickel(II)-EDMA Complexes
Authors: Fujii Yuki 
Published: July 2006

Abstract
The following nickel (II) complexes containing ethylenediaminemonoacetate anion(s) (edma) were newly prepared from an aqueous solution containing nickel(II) ion and edma: [Ni(edma)(H2O)3]X (X=Cl and Br), [Ni(edma)I]4, and [Ni(edma)2]·2H2O. By the thermal decomposition of [Ni(edma)(H2O)3]X, [Ni (edma) X]4-type complexes (X=Cl and Br) were also prepared. By absorbing three molecules of water in an atmosphere, two new, mixed-complexes containing a halogen anion and water molecule(s), [Ni(edma)Cl(H2O)2]·H2O and [Ni(edma)Br(H2O)]2·4H2O (dimer), were prepared from [Ni(edma)X]4. By the measurements of the absorption spectra, the magnetic moments, and the dehydrations, their structures were all assigned to octahedral. The [Ni(edma)X]4 complexes (X=Cl, Br and I) were presumed to have the tetramer structure, where four halogen anions are triply bridged to the nickel(II) ion. The difference between the [Ni(edma)(H2O)3]X, [Ni(edma)Cl(H2O)2]·H2O, and [Ni(edma)Br(H2O)]2·4H2O complexes were clearly observed on the basis of their deri-vatographic behavior. The mechanisms of the dehydrations were also discussed.
The Thermal Annealing Behavior of 80Br Recoils Produced by the Nuclear Isomeric Transitions in Alkali Metal Bromates
Authors: Sasaki Teikichi , Shiokawa Takanobu 
Published: July 2006

Abstract
The transient annealing behavior of bromine recoils produced by isomeric transition was studied in five alkali metal bromates. In the case of 80mBr-labelled potassium bromate, the iso-thermal annealing curves were characterized by maximum and minimum points. A numerical treatment of them indicated that, at the earlier stage of the thermal treatment, the annealing processes proceeded very fast, which was ascribed to the characteristics of the isomeric transition recoils. A remarkable effect of the cationic components on the thermal annealing was observed and interpreted in terms of their ionization potentials.
Transformation of Progesterone by Rhizopus nigricans REF 129 as Influenced by Modification of the Fermentation Medium
Authors: El-Refai Abdel-Monem , Sallam Lotfy , El-Kady Ismail 
Published: July 2006

Abstract
Hydroxylation of progesterone with Rhizopus nigricans REF 129 at C-l1, C-6, C-17, C-21 as well as formation of 11α-hydroxy-5α-pregnane-3,20-dione was investigated when the fermentation medium was modified in a different manner. The various transformation products of progesterone were found to be affected qualitatively and quantitatively by the composition of the medium employed. Mg2+, PO43− proved to be indispensable for the transformation processes. Mn2+ and Fe2+stimulated the reactions. Similarly, acetate, malate and riboflavin enhanced the transformation processes. Formation of the various derivatives of progesterone, except for 11α-hydroxy-5α-pregnane-3,20-dione and 6β, 11α-dihydroxyprogesterone, was also favoured by the addition of adenine, adenosine, uracil and guanine to the fermentation medium.
Synthesis of N-Terminal Nonapeptide of Trypsinogen and Its Hydrolysis by Trypsin
Authors: Yoshida Norio , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
An N-terminal nonapeptide fragment of bovine trypsinogen, H-l-Val-l-Asp-l-Asp-l-Asp-l-Asp-l-Lys-l-Ile-l-Val-Gly-OH, was synthesized via two routes and its susceptibility with trypsin was investigated. Protected derivatives, t-butyloxycarbonyl protected nonapeptide t-butyl ester and benzyloxycarbonyl protected nonapeptide benzyl ester, were prepared by stepwise elongation. Removal of the protecting groups was carried out by treatment with trifluoroacetic acid and hydro-genation respectively. The naked peptide was purified with chromatography on ECTEOLA cellulose column using dilute acetic acid as a solvent. Upon lyophilization the desired nonapeptide was obtained as colorless powder, a portion of the product being digested with trypsin. Rate of tryptic hydrolysis of the peptide was found to be unexpectedly low in the absence of calcium ion, while considerable acceleration of the hydrolysis by calcium ion was noted.