bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sophorol
Authors: Suginome Hiroshi 
Published: July 2006

Abstract
The structure of sophorol was confirmed to be 2′:7-dihydroxy-4′:5′-methylenedioxyisoflavanone by the synthesis of dehydro-O-dimethylsophorol, 2′:7-dimethoxy-4′:5′-methylenedioxyisoflavone.
Plastic Scintillators. III. The Synthesis of Some Anthracene Derivatives as Wavelength Shifters in Plastic Scintillators
Authors: Nakaya Tadao , Tomomoto Takanori , Imoto Minoru 
Published: July 2006

Abstract
Fifteen anthracene derivatives have been synthesized, and their absorption and fluorescence spectra have been measured. The spectra will be discussed in this paper. According to the spectra, some of anthracene derivatives synthesized here are better wavelength shifters than the compounds previously described in the literature.
Nitrous Oxide as an Electron Scavenger in the Radiolysis of Hydrocarbons
Authors: Sato Shin , Yugeta Rei , Shinsaka Kyoji , Terao Terumi 
Published: July 2006

Abstract
Nitrous oxide has been used as an electron scavenger in the radiolysis of hydrocarbons: cyclohexane, cyclohexene, benzene, and their mixtures. Considering that the energy for the formation of an ion pair is about 25 eV. in hydrocarbons, 0.4mol.1−1 of nitrous oxide is not enough to capture all the electrons ejected from irradiated hydrocarbons. In the case of cyclohexane, 70% of the ejected electrons seem to be captured by 0.4mol.1−1 of nitrous oxide. In the case of benzene, G(N2) is about a half of that for cyclohexane. This has been explained tentatively in terms of the ability of benzene to capture electrons. The G(N2)’s in the cases of cyclohexene and benzene have not shown any noticeable dependence on the concentration of nitrous oxide. This shows that hydrogen does not result from the neutralization in these systems. In order to clarify them, the primary processes in the radiolysis of cyclohexane have been further considered using the data previously obtained.
The Trifluoroacetate Method of Peptide Synthesis. II. An Improved Synthesis of Bradykinin
Authors: Sakakibara Shumpei , Inukai Noriyoshi 
Published: July 2006

Abstract
When p-nitrophenyl trifluoroacetate (I), 2, 4, 5-trichlorophenyl trifluoroacetate (II) and N-hydroxysuccinimide trifluoroacetate (III) were subjected to Anderson’s racemization test, only reagent III showed resistance against racemization. However, reagents I and II were also found to be useful for fragment-condensation with acylpeptides possessing glycine or proline at the C-terminus. Bradykinin was prepared using these reagents. During the synthesis, a combination of the t-amyloxycarbonyl N-protecting group and the benzyl ester was mainly used, and the alkaline hydrolysis procedure of the ester group was eliminated. Thus, colorless bradykinin with full activity was obtained in a satisfactory yield without any purification procedure.
The Radiolysis of a Binary Mixture of Tetrahydrofuran with Furan
Authors: Matsui Masao 
Published: July 2006

Abstract
The radiolysis of a tetrahydrofuran(THF) and furan system was studied at a dose of about 2×1019 eV. ml−1 of 60Co-γ-rays, and the hydrogen which may be formed by the no-ring opening and the carbon monoxide which should be formed by the ring scission were determined. The decrease in the hydrogen yield with an increase fraction of furan was found to be greater than had been expected, while G(CO) fit the expected value. The charge transfer mechanism was presumed for the decrease in the hydrogen yield in the γ-radiolysis of this mixture. Suggestions were made on the probable mechanism of the ring opening of the excited molecule for the formation of carbon monoxide, and on the ionic reaction for hydrogen formation. Furthermore, the probability of the ring scission of the THF molecule was roughly estimated by using the assumed decomposition reaction and the determined G values.
Sensitization in the Photoconductance of Poly-N-vinylcarbazole
Authors: Hayashi Yoshiki , Kuroda Makoto , Inami Akira 
Published: July 2006

Abstract
The sensitization in photoconductive poly-N-vinylcarbazole was studied systematically. The sensitizers were conveniently divided into two types, optical and chemical. The optical sensitization occurs with a smaller content of a dye, which extends the photoconductivity spectrum to its absorption band. Effective optical (or dye) sensitizers are found to be themselves photoconductive and n-type cationic and to have a slow photoresponse. The chemical sensitization occurs through the formation of a charge transfer complex with a considerable amount of a Lewis acid. The simultaneous addition of optical and chemical sensitizers induces amplified or additive effects; an amplified effect is observed when a strong acid is employed as a chemical sensitizer. A sensitized system with a strong acid shows a very slow photoresponse and may have fairly deep traps which act as a cause of the memory effect.
Studies of Mixed Cyano Cobalt(III) Complexes. II. The Geometrical Isomers of [CoX(CN)en2]+
Authors: Ohkawa Kuwako , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Two new mixed cyano complexes, cis-[CoCl(CN)en2]Cl (red) and cis-[CoBr(CN)en2]Br (deep rose), have been synthesized and resolved into their optical isomers. The splitting patterns of the ligand field absorption bands of the cis and the trans isomers of the halogenocyanobis(ethylenediamine)cobalt(III) ion have been discussed in relation to the geometrical configurations of the complexes and to the σ- and π-antibonding contribution of the cyanide or the halide ligands to the metal d-orbitals. These studies have been made successfully using the circular dichroism data of the optically active cis-[CoX(CN)en2]X (X=Cl, Br).
The X-Ray Structure Determination of Dihydroteleocidin B Monobromoacetate
Authors: Harada Hirokichi , Sakabe Noriyoshi , Hirata Yoshimasa , Tomiie Yujir\={o} , Nitta Isamu 
Published: July 2006

Abstract
The structure of dihydroteleocidin B monobromoacetate, the derivative of a toxic substance teleocidin B produced by some streptomyces, has been determined by X-ray analysis. Crystals of the derivative, C30H44O3N3Br, are orthorhombic (a=14.50, b=26.60, c=7.93Å, z=4, the space group is P212121). The intensities of 2053 reflections were measured using CuKα radiation. The bromine position was determined by Patterson methods, and all the carbon, oxygen and nitrogen atoms were elucidated by three-dimensional minimum function methods. A three-dimensional Fourier synthesis and the least squares methods completed the refinement, giving a final R value of 16.4%. The derivative has a substituted indole nucleus with a nine-membered lactum ring.
The Effects of Polyamines on the Melting of Polyriboadenylic Acid Plus Polyribouridylic Acid Complexes in a Solution
Authors: Higuchi Shigesada , Tsuboi Masamichi 
Published: July 2006

Abstract
Ultraviolet absorptions of aqueous systems of polyriboadenylic acid (poly A) plus polyribouridylic acid (poly U) have been examined with various Na+ and Mg2+ concentrations and at various temperatures. The transition temperatures (Tm) among the two-stranded conformation, poly(A+U), the three-stranded conformation, poly(A+2U), and the two single-stranded conformations, poly A and poly U, were determined. The effects upon the Tm of adding NH3+-(CH2)nNH3+-type diamines (n=2, 3, 4, 5, 6, and 8), spermine, and actinomycin D to the solutions were observed. It was found that these amines stabilize three-stranded poly(A+2U) more than they stabilize the two-stranded (poly(A+U)) and the single-stranded (poly A and poly U) conformations. Among the diamines examined, those with n=2 and 3 values show a greater effect than those with n=4, 5, 6, and 8 values.
Analytical Studies Using the Convection Electrode. XI. Cathodic Stripping Voltammetry of Chloride Ions with the Pushed-out Mercury Drop Convection Electrode
Authors: Suzuki Junsuke 
Published: July 2006

Abstract
The cathodic stripping voltammetry of chloride ions in a potassium nitrate or a nitric acid solution was studied by using the Pushed-out Mercury Drop Convection Electrode (PMDCE) (J. Suzuki and T. Ozaki, This Bulletin, 37, 230 (1964)). The cathodic stripping peak current, ip, depended upon the rotating rate of the disk, ω (600—1000 r. p. m.); the rate of voltage scan, v(100—300 mV./min.); the pre-electrolysis time, t (∼3 min.), and the bulk concentration of chloride ions, C. It was concluded that the corresponding cathodic peak current, ip can be given by the equation:
ip=kvω1⁄2Ct2⁄3
where k is the constant. In a 0.1 m nitric acid solution, it was possible to determine the chloride ions in so dilute a solution as 3×105− m with a good reproducibility.
Solvent and Steric Effects on the Solvolysis of Polyvinylsulfonic Acid Esters
Authors: Yoshikawa Sadao , Kim Oh-Kil , Hori Takeshi 
Published: July 2006

Abstract
The solvolysis of ethanesulfonic acid esters followed closely first-order kinetics, while the case of polyvinylsulfonic acid esters gave strongly-curved first-order plots according to the solvent composition. With a high acetone content, the solvolysis rates of polymeric sulfonic esters decreased gradually with the lapse of time, while in a high water content, the solvolysis was suppressed at the beginning of the reaction but was accelerated remarkably with the reaction time. The former finding indicates the release from the steric congestion which contributed to the initial rate enhancement, while the latter indicates the aggregation of the polymer molecules owing to their strong hydrophobic character. The solvolysis rates, kp, for polymeric sulfonic esters were much greater than those, km, for monomeric analogs in all cases except isopropyl and n-butyl esters in 20% aqueous acetone. The relative rate (kp/km) increased with an increase in the acetone content and was apparently greater with the methyl ester than with the other esters, and the value of (kp/km) in relation to the methyl ester in 80% acetone content reached 15. Furthermore, it was found that the proton catalysis by the neighboring sulfonic acid formed on the lapse of reaction time was absent, and also that the salt effect was negligibly small.
The Reactions of N,N-Dimethylbenzamide Diethylmercaptole
Authors: Mukaiyama Teruaki , Yamaguchi Tatsuaki 
Published: July 2006

Abstract
The reactions of N,N-dimethylbenzamide diethylmercaptole with active methylene compounds, amines, hydrazines, benzaldoxime, benzhydroxamic acid and heavy metal salts have been studied. Active methylene compounds, hydroxylamine, hydrazine and phenylhydrazine were found to react with N,N-dimethylbenzamide diethylmercaptole to give the corresponding α-dimethylaminobenzylidene derivatives by eliminating ethyl mercaptan. In addition, such heterocyclic compounds as 2-phenylimidazoline, 2-phenyloxazoline and 2,5-diphenyl-1,3,4-oxadiazole were derived from- N,N-dimethylbenzamide diethylmercaptole by cyclization reactions with ethylenediamine, 2-aminoethanol and benzoylhydrazine respectively. Further, it was found that N,N-dimethylbenzamide diethylmercaptole reacted with benzaldoxime and benzhydroxamic acid to give the dehydrated products benzonitrile and phenyl isocyanate respectively. Finally, it was established that heavy metal salts, such as mercuric oxide, mercuric cyanide and silver cyanide, reacted with N,N-dimethylbenzamide diethylmercaptole to liberate heavy metal mercaptides, thus giving N,N-dimethylbenzamide, N,N-dimethylbenzamide dicyanide and N,N-dimethylbenzamide ethylmercaptocyanide respectively.
Studies on d-Glucosamine Derivatives. XIII. The Synthesis of N-Acetyl-1-O-aminoacyl-d-glucosamines
Authors: Yoshimura Juji , Funabashi Masuo 
Published: July 2006

Abstract
For the purpose of examining the properties of the glycosidic ester linkage of sugars to amino acids, N-acetyl-1-O-aminoacyl-d-glucosamines were synthesized. N-Acetyl-4,6-O-benzylidene-d-glucosamine was condensed with an equimolar amount of N-benzyloxycarbonyl amino acids by the dicyclohexylcarbodiimide method, followed by the hydrolytic and hydrogenolytic removal of the protecting groups. N-Acetyl-3-O-acetyl-d-glucosamine was also newly prepared as a contrast compound.
Organoboron Compounds. XI. The Polymerization of Vinylboronic Acid
Authors: Kato Seiji , Kimura Keiko , Nagata Katsuhisa , Tsuzuki Yojiro 
Published: July 2006

Abstract
It has been found that potassium persulfate is a good initiator for the polymerization of vinylboronic acid. With this initiator the polymerization has been studied in acidic as well as in basic medium, and the best conditions for the polymerization have been established with the help of molecular weight determination of the products. The highest molecular weight has been observed in basic medium to be about 7000. A mixed solvent (1:1) of ether and acetone has been used as the precipitant. The variation in the rate of polymerization and the boron content has been investigated in a narrow range of pH, from 6 to 8.
The Dimerization of Ethylene Using Palladous Chloride as the Catalyst
Authors: Kusunoki Yasuo , Katsuno Ryokei , Hasegawa Noboru , Kurematsu Susumu , Nagao Yoshio , Ishii Kanzi , Tsutsumi Shigeru 
Published: July 2006

Abstract
The dimerization of ethylene was carried out using palladous chloride as the catalyst. Acetic acid, ethylene dichloride, ethylene tetrachloride, benzene, chlorobenzene, triethyleneglycol, acetic acid esters, chloroform, cyclohexane and ethanol were employed as the reaction solvents, and the effects of these solvents on the reaction were investigated. The best yield of butylene (about 1500 mol.% to palladous chloride) was obtained, when acetic acid was used as the solvent; the yield decreased gradually following the above order of solvents until, when ethanol was used as the solvent, it yielded only 96 mol.%. However, in all solvents dimerization was carried out predominantly, and only a few higher polymers were obtained. It is very interesting that the solvent effect mentioned above was different from the effect of solvents in the isomerization of olefin when metal carbonyl was used as the catalyst. To explain these results, a hydride ion-shift mechanism has been proposed.
A New Method of Quantitative Differential Thermal Analysis
Authors: Ozawa Takeo 
Published: July 2006

Abstract
This paper presents a rigorous new theory of differential thermal analysis, taking account of the temperature gradient in the sample. From this consideration, a new quantitative method is proposed, where a solid-cell holder of low thermal conductivity is set between a sample cell and a metal block, and a thermocouple is inserted tightly between the outside wall of the cell and the cell holder. By means of this arrangement, the peak area becomes proportional to the heat of transformation, irrespective of the kinds and the states of samples and operational variables. The experimental verification using various samples and the effect of several operational variables, such as the heating rate, the concentration of a diluent, the packing density, and the depth of the packing sample, are also shown; satisfactory results are obtained. Two new concepts, the sensitivity and the response time of the system, are proposed and evaluated. Conventional methods are criticized, and the inherent limitations of differential thermal analysis are discussed.
Proton Magnetic Resonance Spectra of Cobalt(III) Hexammine-type Polyamine Complexes
Authors: Yoneda Hayami , Morimoto Yukiyoshi 
Published: July 2006

Abstract
The proton magnetic resonance spectra of [Co en3]Cl3, [Co tn3]Cl3, [Co pn2]Cl3 and [Co den2]Cl3(den=diethylenetriamine) dissolved in trifluoroacetic acid were measured. All of the observed spectra consist of broad bands, which were assigned on the basis of intensity considerations and by comparing them with the spectra of the corresponding deuterated species. In case of the ethylene-diamine complex, the double-resonance method was applied, measurements at different temperatures were made, and the origin of the breadth of the bands was discussed. The NH2 signals of the ethylenediamine and trimethylenediamine complexes show AB-type features. This was confirmed by comparing the spectra obtained at 60 Mc. and at 100 Mc. The AB-type features of the NH2 signal were explained in terms of the crystal structure of the complex.
Infrared Spectroscopic Study on Ion Association of Hexacyanoferrate(III) and Hexacyanoferrate(II) Ions
Authors: Tanaka Nobuyuki , Kobayashi Yumiko , Kamada Minoru 
Published: July 2006

Abstract
The ion association of hexacyanoferrate(III) and hexacyanoferrate(II) anions with univalent or bivalent cations in aqueous solutions has been studied by the measurement of the infrared absorption band due to the C≡N stretching vibrations. All the solutions measured in which ion-pairs with hexacyanoferrates(III) predominated gave an absorption maximum at 2121 cm−1, and those in which ion-pairs with hexacyanoferrates(II) predominated, at 2020 cm−1, although hexacyanoferrates(III) and hexacyanoferrates(II) of potassium and alkaline earth metals gave different spectra from each other in solid state. No difference in absorption band obtained with different solutions was supported by the distance between two ions in ion-pair, which was estimated from the structures of hexacyanoferrate(III) and hexacyanoferrate(II) ions and the closest approach of the ion-pair; this indicates that there is no direct interaction between the complex anion and the cation, but one or more water molecules interpose between the two ions.
A Spectrophotometric Study of the Complex Formation between Iron(III) and Salicylic Acid
Authors: Ogawa Kin’ya , Tobe Nobuko 
Published: July 2006

Abstract
A spectrophotometric study of the complex formation between iron(III) and salicylic acid was carried out over the pH range up to 6; further, an attempt was made to test the applicability of salicylic acid as a reagent for the spectrophotometric determination of iron (III) in the presence of iron(II). The absorption maxima of the mixture of iron(III) and salicylic acid are found at 530 mμ independently of the pH between 0.7 to 2.5, while they shift to shorter wavelength when the pH rises above 3. The isosbestic point occurs at 550 mμ between pH values from 3 to 6. It was concluded that three complex species, Fe(Sa)+, Fe(Sa)2−, and Fe(Sa)3−3, are formed successively in acid solutions; their stability constants were determined to be:
(Remark: Graphics omitted.)
where Sa2− denotes the salicylate anion, C6H4(O−)(COO−). If the pH of the solution is adjusted from 2 to 3 and if absorbancy measurements are made at 515 to 500 mμ, salicylic acid can be used as a reagent for determining iron(III) in the presence of iron(II). The optimum concentration of iron(III) is 2 to 12 p. p. m.; iron(II) does not interfere, even at a concentration of 100 p. p. m.
The Lifetime of Excimer Fluorescence of Naphthalene
Authors: Azumi Tohru , Azumi Hiroshi 
Published: July 2006

Abstract
The radiative lifetimes of the excimer fluorescence of naphthalene are calculated for excimers of various geometrical configurations. The results vary, to a great extent, with the configurations, but with a previously-suggested configuration the calculated lifetime is 6×10−6 sec. This is within a factor of 5 of the experimental results.
Intermediates in the Photoreduction of Eosine as Revealed by a Flash-Photolysis Study
Authors: Ohno Takeshi , Kato Shunji , Koizumi Masao 
Published: July 2006

Abstract
Besides the triplet state, semi-reduced eosine (Rd) and semi-oxidized eosine (Ox) were observed as transient intermediates in an aqueous solution; the former has a peak at 408 mμ, and the latter, one at 456 mμ. These two species are produced by the reaction DT+D→Rd+Ox or DT+DT→Rd+Ox. The sum of the rate constants for the reactions DT+D→Ox-+Rd and DT+D→2D is about 8.0×108 m−1 sec−1, approximately equal to the sum of the rate constants for DT+DT→2D and DT+DT→Ox+Rd. Triplet eosine, by reacting with ATU or EDTA, produces two kinds of half-reduced eosine, Rd′ and Rd″, which have absorption spectra similar to those of Rd but with different life-times. These are perhaps loose compounds of half-reduced dye and a half-oxidized reductant. The rate constants for DT+ATU→Rd′ and DT+EDTA→Rd″ are 3.4×105 m−1 sec−1 and 5×105 m−1 sec−1 respectively. Rd disappears bimolecularly by means of the Rd+Ox→2D reaction with the rate constant of 8.8×107 m−1 sec−1. Ox, by reacting with EDTA or ATU, regenerates the original dye with the rate constants of 1×106 and 8×105 m−1 sec−1 respectively. The results enable us to conclude that the D–D mechanism occurs under suitable conditions.
The Electronic Spectra of 1,1′-Dianthrylpoly-ynes
Authors: Nishimoto Kichisuke , Fujishiro Ryoichi , Akiyama Shuzo , Nakagawa Masazumi 
Published: July 2006

Abstract
The electronic spectra of 1,1′-dianthrylpoly-ynes have been studied by Hückel MO theory on the basis on various approximations for resonance integrals. A good agreement between theoretical and experimental values is obtained from a modified bond-alternation approximation. This result shows that the contribution of a cumulene-type ionic structure to the ground state of the molecule increases with an increase in the number of the triple bonds.
Studies of the Aqueous Solution of a Surface Active Substance by Means of an Ultrasonic Interferometer. II. The Effects of Added Electrolytes on the Dissolved State of Sodium Alkyl Sulfate
Authors: Shigehara Koji 
Published: July 2006

Abstract
The sound velocity (U) and the density of aqueous solutions of sodium dodecyl (SDS) and octyl (SOS) sulfates with inorganic electrolyte have been measured by using a differential ultrasonic interferometer and a float balance respectively, and the compressibility (β) has then been calculated from these results. The CMC’s of SDS solutions of various concentrations of sodium salts have been determined from U-vs.-SDS and β-vs.-SDS concentration (C2) diagrams. The results show a linear relationship between the logarithm of CMC and the logarithm of the concentration of sodium ions. The values of dβ⁄dC2 below CMC are affected by the addition of electrolytes, while the values above CMC are almost not affected at all by the addition of electrolytes. The diagrams of dβ⁄dC2 of alkyl sulfate vs. the number of carbon atoms in alkyl sulfate molecules with varying concentrations of added electrolytes showed straight lines which all passed through the same point when extrapolated to a zero number of carbon atoms. These results have been explained by taking account of the dissolved state of a surface active substance under the builder action of added inorganic electrolytes, which action decreases not only the mutual repulsion of the ionized-head group of a surface active substance but also the non-ionic hydration of the CH2-chain of the surface active substance.
The Reactions of t-C4H9+ in the Radiolysis of Neopentane in the Gas Phase
Authors: Miyazaki Tetsuo , Shida Shoji 
Published: July 2006

Abstract
The yields and reactions of t-C4H9+ produced in the radiolysis of neopentane in the gas phase have been studied by the use of ammonia. The yields of iso-C4H8 increase sharply upon the addition of a small amount of ammonia in the radiolysis of neopentane and show a constant value upon the further addition of ammonia (more than 10 mol.%). Since this increase is due to the following reaction:
t−C4H9++NH3→ iso−C4H8+NH4+
we get G(t-C4H9+)=1.76 by assuming the increment of iso-C4H8 to be equal to the yield of t-C4H9+. This value is consistent with the value expected from the mass spectrum of neopentane. It has, therefore, been concluded that the ammonia method is a very effective general method for studying the reactions of ions. It is applicable to the study of ions under high pressures, ions which can not be studied by a mass spectrometer. It is especially effective in the study of less reactive ions.