bluuebunny/crossref_metadata_2025_split huggingface dataset:
An X-Ray Crystallographic Study on the Absolute Configuration of Dihydroyashabushiketol and the Solvent-dependence of Its Optical Rotation
Authors: Suga Takayuki , Ohta Shinji , Aoki Tadashi , Hirata Toshifumi 
Published: July 2006

Abstract
The absolute configuration of dihydroyashabushiketol was established to be S on the basis of the X-ray crystallographic analysis of the 4′,4″-dibromo derivative. In addition, it was found that the sense of the optical rotations of dihydroyashabushiketol and its dibromo derivative is determined by the interaction of their C-5 hydroxyl group with the solvent used for the measurements.
Studies of Collectors. V. The Preparation of Amidoxime-type Surfactants and the Flotation of a Trace Amount of Uranium
Authors: Koide Yoshifumi , Takamoto Hiroaki , Matsukawa Katsunori , Yamada Kimiho 
Published: July 2006

Abstract
This study investigates the flotation of uranium with four amidoxime-type surfactants (R12Ax, R16Ax, Ls8.6Ax, and Ls7.2Ax6.0Hx). Ls7.2Ax6.0Hx was prepared by the telomerization of acrylonitrile and acrylamide using 1-dodecanethiol as a solvent, followed by treatment with hydroxylamine. Uranium could be floated effectively at pH 5.0 with R12Ax, R16Ax, or a combination of Ls8.6Ax and a nonionic surfactant. The floatability for uranium present in sea water was 43% after the addition of 1 mg R16Ax and 90% after the addition of 30 mg R12Ax. Ls7.2Ax6.0Hx formed a soluble complex, and 72% of the uranium present in sea water could be collected at pH 8.0 by foam fractionation using Ls7.2Ax6.0Hx. Little surfactant remained in the residual solution, and it was regenerated from an acidic solution dissolving the scum or froth.
Studies on Thermodynamics for the Hydrolysis. II. The Temperature Effect on the Stereoselective Deacylation of Amino Acid Esters in Bilayer and Micellar Systems
Authors: Matsumoto Y\={o}ko , Ueoka Ryuichi 
Published: July 2006

Abstract
Stereoselective deacylations of p-nitrophenyl N-acyl-d(or l)-phenylalaninates(d(or l)-Sn; n=2, 12, and 16) and N-benzyloxycarbonyl-d(l)-phenylalaninates(d(l)-ZS) by the bilayer and micellar catalytic systems of l-histidine derivatives (LauHis, MyrHis, PalHis, LauHisLeu, and MyrHisLeu) and surfactants (2CmN2C1Br with m=12, 14, and 16, CTAB, OTAC, and (R)-(+)-SUR16) were performed. It is noteworthy that the temperature dependence of enantioselectivity for the deacylation of S12 having a long acyl chain is bell-shaped with maxima at 25 °C and 15–25 °C in the bilayer systems of MyrHis+2C12N2C1Br and MyrHisLeu+2C12N2C1Br, respectively. On the other hand, the enantioselectivity for the S12 deacylation catalyzed by LauHisLeu in the presence of the CTAB micelles increases as temperature is lowered (the highest enantiomer rate ratio (kLa,obsd⁄kDa,obsd=12) is attained at 20 °C). The enantioselectivity for the deacylation of S2 having a short acyl chain, however, is almost constant and considerably lowered in comparison with that for the deacylation of S12 in both the bilayer and micellar systems. According to the isokinetic temperature (β), the deacylation of Sn (n=2 and 12) and ZS in the bilayer systems might be entropy-driven, whereas that in the micellar systems might be enthalpy-driven. The stronger hydrophobic microenvironment of the bilayer systems in the ester-deacylation would probably be connected with the entropy-driven nature.
Band-structure Parameters of Organic Conductors, TSeT2Cl, TTT2I3, and TSeT2SCN
Authors: Mori Takehiko , Kobayashi Akiko , Sasaki Yukiyoshi , Kobayashi Hayao 
Published: July 2006

Abstract
The band-structure parameters of organic conductors, TSeT2Cl, TTT2I3, and TSeT2SCN (TSeT; 5,6: 11,12-bis(diseleno)naphthacene; common name: tetraselenotetracene, and TTT; 5,6:11,12-bis(dithio)naphthacene; common name: tetrathiotetracene) were calculated using semiempirical molecular-orbital calculations. The longitudinal bandwidth W and the anisotropy parameter α of TSeT2Cl were obtained as 0.6 eV and 0.188 respectively. The shape of the Fermi surface, as calculated from the tight-binding theory and the large anisotropy parameter, agrees with its semimetallic nature at low temperatures. In TTT2I3, W=0.56 eV, and α=0.018. This compound was regarded as a one-dimensional metal. The semiconductive conduction of TSeT2SCN was interpreted in terms of the small bandwidth, W=0.26 eV.
Alizarin Red-S, an Amperometric Reagent for Ultramicro and Microgram Estimation of Sm3+ and Gd3+
Authors: Lavale S C , Pitre K S 
Published: July 2006

Abstract
Alizarin Red-S has been employed successfully as an amperometric reagent for the precise determination of Sm3+ and Gd3+ in aqueous and partially non aqueous media. Amperometric titrations have been performed at −0.7 V vs. Hg-pool, pH=4.5 and μ=0.1. The current-volume titration curves obtained were well defined, indicating 1:2 stoichiometric ratio of metal:ARS complexation in each case. The absorptiometric studies made on the equilibrium of above complexation also confirm the said ratio. Many ions do not interfere the titration procedure.
Liquid-Liquid Distribution of 4-Acyl-3-methyl-1-phenyl-5-pyrazolones and Their Zinc Complexes
Authors: Umetani Shigeo , Matsui Masakazu 
Published: July 2006

Abstract
The distribution of eight 4-acyl-3-methyl-1-phenyl-5-pyrazolones and their zinc complexes between aqueous and cyclohexane phases was investigated. The acid dissociation constants and partition constants of the extractants were discussed in terms of a substituent effect. It was found that two series of examined reagents in which one has an aromatic substituent at the 4-position of 5-pyrazolone, and the other an aliphatic one give similar extraction constants. Since their acid dissociation constants are essentially the same, a relationship, logPMA=2logPHA+ constant, is postulated. The extraction constant of a fluorinated reagent which has a considerably small pKa value is also similar to that of the reagents having aliphatic substituents. Another relationship, logβ2=2pKa+ constant, is postulated.
Infrared ATR Measurements at Low Temperatures. An Apparatus and the Absorption Intensities of Crystalline Benzene and Carbon Disulfide
Authors: Yamada Haruka , Saheki Masao 
Published: July 2006

Abstract
An infrared ATR apparatus for use at low temperatures was constructed for the determination of the optical constants and absorption intensities of crystalline samples. The ATR spectra of benzene and carbon disulfide polycrystals were measured with two different incident angles. The optical constants and then the absorption intensities were accurately obtained for the fundamental bands from these ATR spectra. Experiments for transmission spectra were also carried out with an improved absorption cell at low temperatures, confirming the present ATR results. A comparison of the intensities in different phases was made for the ν18, ν19, ν20, and ν11 fundamental bands of benzene and the ν3 band of carbon disulfide.
Use of an Ion-selective Electrode as a Detector in Ion Pair Chromatography
Authors: Jyo Akinori , Mori Kenji , Ishibashi Nobuhiko 
Published: July 2006

Abstract
A chloride ion-selective electrode was used as a detector for inorganic anions separated by ion pair chromatography. Excellent performance of the electrode detector was demonstrated by detection of chloride, iodide, and thiocyanate.
Determination of Small Amounts of Carbazole in Anthracene by Synchronous Fluorescence Spectrometry
Authors: Furusawa Motohisa , Tachibana Masaki , Fujishima Mamiko 
Published: July 2006

Abstract
After converting anthracene into the Diels-Alder adduct by the reaction with maleic anhydride, and converting the adduct into a water-soluble salt by hydrolysis with potassium hydroxide aqueous solution, carbazole is then extracted into 2,2,4-trimethylpentane together with other impurities. Then carbazole can be determined by synchronous fluorescence spectrometry without interference of the impurities.
Photochemical Synthesis of the Acetylene Adducts and Dimers of 2H- and 4H-1-Benzopyranones
Authors: Matsui Takanao , Nakayama Mitsuru 
Published: July 2006

Abstract
7-Methoxychromone reacts photochemically with acetylene to form 5-methoxy-2a,8a-dihydro-8H-banzo[b]cyclobuta[e]pyran-8-one and its valence isomer. Photoaddition of acetylene to 6-methoxychromone and 7-methoxy-4-methylcoumarin did not proceed, but the latter underwent photodimerization to give the head-to-tail dimers.
Preparation of Sydnone-4-carboxamide Oximes and Their Conversion into 4-(1,2,4-Oxadiazol-3-yl)sydnones
Authors: Yeh Mou-Yung , Nonaka Tsutomu , Goto Takushi , Hsu Ming-Ching , Fuchigami Toshio , Tien Hsien-Ju 
Published: July 2006

Abstract
3-Arylsydnone-4-carboxamide oximes (2) were prepared from the corresponding 3-arylsydnone-4-carbonitriles and hydroxylamine in high yields. The amide oximes 2 reacted with orthoesters to give 3-aryl-4-(1,2,4-oxadiazol-3-yl)sydnones.
The Configurations of N-Methyl- and N-t-Butyl-α-methoxycarbonylmethanimine N-Oxides
Authors: Inouye Yoshinobu , Takaya Kazuharu , Kakisawa Hiroshi 
Published: July 2006

Abstract
N-Methyl-α-methoxycarbonylmethanimine N-oxide, Z configuration in crystal, was found to exhibit a facile equilibration with its E-isomer in solution. The configuration of N-t-butyl derivative was always Z.
Viscosity B-Coefficients, Apparent Molar Volumes, and Activity Coefficients for α- and γ-Cyclodextrins in Aqueous Solutions
Authors: Miyajima Koichiro , Sawada Masahiro , Nakagaki Masayuki 
Published: July 2006

Abstract
The viscosities and densities at 15, 25, and 35 °C, and activity coefficients at 25 °C for the aqueous solutions of α- and γ-cyclodextrins were measured, and the results were interpreted in terms of solute-solvent and solute-solute interactions. The concentration and temperature dependences of viscosities and apparent molar volumes are almost similar to those of linear saccharides, i.e. maltose and maltotriose, indicating that α- and γ-cyclodextrins are structure forming solutes. However, the concentration dependences of activity coefficients of cyclodextrins are significantly different from those of maltose and maltotriose. The results were tentatively assigned to the formation of dimer in aqueous solutions.
Spectrophotometric Determination of Ruthenium(III) and Rhodium(III) with 9,10-Phenanthrenequinone Monoxime after Extraction into Molten Naphthalene
Authors: Wasey Abdul , Bansal Raj K , Satake Masatada , Puri Bal K 
Published: July 2006

Abstract
9,10-Phenanthrenequinone monoxime has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction into molten naphthalene. The extracted mixture of the metal complex and naphthalene was dissolved in chloroform and ruthenium and rhodium were determined spectrophotometrically. Beer’s law holds in the concentration range of 0.2–4.1 μg/cm3 for ruthenium and 0.3–5.3 μg/cm3 for rhodium in 10 cm3 of the final solution. The molar absorptivities and Sandell sensitivities are calculated to be 9.70×103 l mol−1 cm−1 and 0.01 μg/cm2 (660 nm) for ruthenium and 1.13×104 l mol−1 cm−1 and 0.009 μg/cm2 (410 nm) for rhodium respectively. Aliquots containing 2.0 μg of ruthenium and 4.1 μg of rhodium give mean absorbances of 0.192 and 0.451 with standard deviations of 0.0017 and 0.0039, respectively. Interference of various ions has been studied and the method has been applied to the determination of ruthenium and rhodium in various synthetic mixtures. This procedure is also applied to the simultaneous determination of ruthenium and rhodium present together in a solution.
The Stereochemistry and Reactivity of Metal-Schiff Base Complexes. VI. The Kinetics and Mechanism of Isomerization between ΔL-β2- and ΛL-β2-Diastereoisomers of N,N′-Ethylenebis(α-methylsalicylideneaminato)cobalt(III) Complexes with l-Amino Acid
Authors: Fujii Yuki , Kobayashi Takemaru , Matsufuru Makoto , Takahashi Sozo 
Published: July 2006

Abstract
The kinetics for isomerization between ΔL-β2- and ΛL-β2-diastereoisomers of [Co(α-Me-sal2en)(l-aa)], where l-aa represents l-phe, l-met, l-ile, l-pro, N-Bz–l-ala, and N-Me–l-ala, were studied in methanol. The activation enthalpies (ΔH\eweq/kJ mol−1) and the activation entropies (ΔS\eweq/J K−1 mol−1) from the ΔL-β2-isomer (unstable form) to the ΛL-β2-isomer (stable form) were determined to be 86.6 and −9.6 for l-phe, 92.5 and +6.7 for l-met, 87.5 and −8.0 for l-ile, 100.4 and +28.0 for N-Bz-l-ala, and 102.9 and +18.4 for N-Me-l-ala, respectively. For l-procomplex, the ΔL-β2-isomer is the stable form, and the enthalpy and entropy for isomerization from ΛL-β2- to ΔL-β2- isomers were 96.2 and 0.0. The isomerization was catalyzed by acids but not by bases, and was much faster than the substitution of coordinated l-amino acid. The H–D exchange of N–H proton of N-Me–l-ala-complex proceeded with almost the same rate as the isomerization. The isomerization showed strong solvent dependency; it was fast in a hydrogen-bonding solvent, but was quite slow in a weak- or nonhydrogen-bonding solvent. On the basis of these facts, proton-assisted and/or hydrogen-bonding solvent-assisted intramolecular mechanism via an intermediate is proposed, in which the Schiff base takes a planar configuration and the amino acid coordinates as a unidentate ligand with its carboxylate group.
Electron Spin Resonance Study of X-Irradiated Single Crystals of Silver(I) Nitrate–Butanedinitrile(1/1)
Authors: Kurita Yukio , Ohigashi Hiroji 
Published: July 2006

Abstract
ESR spectra of single crystals of silver(I) nitrate–butanedinitrile(1/1) were measured at 77 K. Two paramagnetic centers, –CN···Ag2+···NC– and NO32−···Ag+, appeared simultaneously on X-irradiation at 77 K. The principal values of the g value (g) and the hyperfine coupling constants (A in the units of 10−1 cm−4) were g1=2.050, g2=2.053, and g3=2.302, A(Ag)1=21.8, A(Ag)2=22.0, A(Ag)3=34.9, A(N)1=15.3, A(N)2=15.9, and A(N)3=14.0 for the first center, and g⁄⁄=2.001, g⊥=2.006, A(Ag)⁄⁄=20.3, A(Ag)⊥=17.4, A(N)⁄⁄=59.4, and A(N)⊥=32.8 for the second center. When the crystals X-irradiated at 77 K were exposed to visible light, the two centers disappeared simultaneously and the NO2 radicals increased. When the crystals X-irradiated at 77 K were warmed to room temperature, the first center changed to a new paramagnetic center, in which the unpaired electron coupled with a silver nucleus, two equivalent nitrogen nuclei, and a proton.
Studies of Polystyrene-based Ion Exchange Fiber. I. The Preparation and Fundamental Characteristics of Polystyrene-based Ion Exchange Fiber
Authors: Yoshioka Toshio , Shimamura Masaharu 
Published: July 2006

Abstract
A polystyrene-based ion exchange fiber which has a large ion exchange capacity (ca. 2.5 mequiv g−1) and a high mechanical strength (ca. 1.4 g d−1) has first been prepared by using an islands-in-a-sea type composite fiber, the sea ingredient predominantly comprised of polystyrene for ion exchange and the island ingredient comprised of fiber-forming polypropylene for reinforcement, as the starting material; it can be used in an arbitrary form. It was found that the resulting fiber has two fundamental characteristics; the ion exchange rate for metal ions is extremely high, and the capacity of adsorbing the macromolecular ionic substance is exceedingly large, compared with ordinary ion exchange resins. The diffusion equation of ion exchange in the case of a cylindrical, endless fiber was solved by a modification of the method used for a spherical resin in a simple system. The former results are interpreted in terms of their solutions for two limiting cases. The latter results are explained by the fact that the surface-area ratio of the fiber to the resin is about ten.
The X-Ray and NMR Studies on the Regio- and Stereoselective Courses for Insertion of Ketones into the s-cis- and s-trans-Diene Complexes of Zirconium Leading to (Z)-1,2-Oxazirconacyclohept-4-enes
Authors: Kai Yasushi , Kanehisa Nobuko , Miki Kunio , Kasai Nobutami , Akita Munetaka , Yasuda Hajime , Nakamura Akira 
Published: July 2006

Abstract
The s-trans-diene coordination in (η5-C5Me5)2Zr(butadiene) and the s-cis-diene coordination in (η5-C5Me5)2Zr(isoprene) were confirmed by the 1H- and 13C-NMR spectral studies. The reaction of 2,4-dimethyl-3-pentanone with these complexes occurred regio- and stereoselectively to give (Remark: Graphics omitted.) (5: R=H, 6: R=Me). The X-ray crystal structure analysis of 5 and 6 revealed the (Z)-configuration with respect to the olefin part. Crystal data for 5: monoclinic, space group P21/n with Z=4, a=11.650(2), b=17.791(3), c=13.612(2) Å, β=92.20(2)°, R=0.111 for 4308 non-zero reflections. Crystal data for 6: monoclinic, space group P21/n with Z=4, a=10.279(3), b=30.177(4), c=9.955(2) Å, β=108.67(2), R=0.104 for 3526 non-zero reflections.
Racemization of Optically Active Amino Acid Salts and an Approach to Asymmetric Transformation of Dl-Amino Acids
Authors: Hongo Chikara , Yoshioka Ryuzo , Tohyama Masanori , Yamada Shigeki , Chibata Ichiro 
Published: July 2006

Abstract
In connection with optical resolution of Dl-amino acids, the racemization process of optically active amino acid salts was studied. A wide variety of salts of optically active amino acids with sulfonic acids or mineral acids could be racemized by heating in a medium of acetic acid at 80–100 °C for 1 h in the presence of 0.1 molar equivalents of an aldehyde and free Dl-amino acid. From the reaction mixture, the racemized Dl-amino acid salts were recovered in high yield (86–92%) and in high purity. An asymmetric transformation between two enantiomers of amino acid salt was attempted by the combination of preferential crystallization of the desired enantiomer and racemization of the antipode in the liquid phase. Dl-Alanine p-chlorobenzenesulfonate was partially converted to l-isomer (yield 16%, optically purity 97%). Another approach was carried out by transformation between two diastereoisomeric salts. The combination of selective precipitation of less soluble diastereoisomeric salt and epimerization of soluble diastereoisomeric salt allowed Dl-phenylglycine d-camphor-10-sulfonate to be partially converted to d-phenylglycine d-camphor-10-sulfonate (yield 68%, optical purity 96%).
Tetraammineplatinum(II)–Hydrogen Ion Exchange on α-Zirconium Phosphate and the Characterization of Its Complex Cation Form
Authors: Hasegawa Yoshitsugu , Yamamine Giichi 
Published: July 2006

Abstract
The tetraammineplatinum(II)–hydrogen-ion exchange on α-zirconium phosphate has been investigated. The ion-exchange process was examined by measuring the change in the pH values of the supernatants. α-Zirconium phosphate loaded with tetraammineplatinum(II) was characterized by means of chemical analysis, X-ray diffractometry, infrared spectroscopy, and thermal analysis. The ion-exchange reaction proceeded more easily than the hexaaminecobalt(III)–hydrogen-ion exchange, and about 50% of the hydrogen ions in α-zirconium phosphate were replaced by tetraammineplatinum(II). The interlayer distance of the exchanger expanded from 7.60 to 10.7 Å.
Reduction of Macrocyclic Cobalt(III) Complex Photosensitized by Tris(2,2′-bipyridine)ruthenium(II)
Authors: Kurimura Yoshimi , Endo Emiko 
Published: July 2006

Abstract
The photosensitized reduction of macrocyclic cobalt(III) complex, [Co(N4)(OH2)2]3+ (N4=Me6[14]4,11-dieneN4), occurs rapidly in an anaerobic [Ru(bpy)3]2+/[Co(N4)(OH2)2]3+/triethanolamine solution. The mechanistic implications of the photosensitized reaction are discussed.
Succinate-complexed Octacalcium Phosphate
Authors: Monma Hideki , Goto Masaru 
Published: July 2006

Abstract
A succinate-complexed calcium phosphate has been synthesized by conducting the hydrolysis of α-tricalcium bis(phosphate) in the presence of succinate ions. The organic substance is considered to be introduced into the structure of the hydrolysis product, i.e., octacalcium bis(hydrogen-phosphate) tetrakis(phosphate) pentahydrate, through the replacement of HPO42− by C4H4O42−.
Absolute Configurations Assigned to Some Octahedral cis-Bis(diamine)cobalt(III) Complexes on the Basis of Their Stereoselective Interactions in Solution
Authors: Miyoshi Katsuhiko , Watanabe Kenzo , Toda Yoshihisa , Yoneda Hayami 
Published: July 2006

Abstract
Absolute configurations are assigned to some cationic cis-[Co(diamine)2(X)(Y)]n+-type complexes by detecting the direction of the chiral equilibrium shift induced for [Cr(ox)3]3− in the presence of these chiral complexes in water–dioxane mixtures. The assignments are found all consistent with those made earlier by CD spectra.
Coagulated Ion-exchanger Colorimetry for the Determination of Trace Amounts of Sulfide as Methylene Blue
Authors: Matsuhisa Kiichi , Ohzeki Kunio , Kambara Tomihito 
Published: July 2006

Abstract
Sulfide ion was converted to Methylene Blue through the reaction with N,N-dimethyl-p-phenylenediamine in the presence of iron(III) ion. The dye produced was fixed by batch method onto the coagulated mixture of finely divided anion and cation exchange resins. The coagulated material was collected by filtration on a filter paper as a disk of thin layer, which was then soaked in an acetate buffer solution, and subjected to the spectrophotometric analysis. The calibration graph was linear over the range 1.03–10.3 nmol of sulfide. The method was applied to some hot spring waters.
Cycloaddition of Diphenylcyclopropenone with Carboximidate, Carboximidamide, and Carboximidothioate
Authors: Yoshida Hiroshi , Sogame Shingo , Bando Shoichi , Nakajima Shosuke , Ogata Tsuyoshi , Matsumoto Kiyoshi 
Published: July 2006

Abstract
The reaction of diphenylcyclopropenone with R1N=C(R2)X (2) (R1, R2= alkyl, aryl, X=MeO, EtO, MeS, or Me2N) gave 2-pyrrolin-4-one (3) in good yield. The less reactive carboximidothioate (2, R1=4-MeC6H4, R2=Ph, X=MeS) yielded isomeric 3-pyrrolin-2-one together with 3.
Molecular Force Fields of s-trans-1,3-Butadiene and the Second Stable Conformer
Authors: Furukawa Yukio , Takeuchi Hideo , Harada Issei , Tasumi Mitsuo 
Published: July 2006

Abstract
Normal-coordinate analyses of s-trans-1,3-butadiene and its various deuterated and 13C-substituted analogs were performed using the group-coordinate force field, and a set of force constants was determined. The infrared spectra of the second stable conformer of 1,3-butadiene-d0, -1,1,4,4-d4, and -d6 were analyzed on the basis of normalcoordinate calculations of the planar s-cis form and a nonplanar gauche form. Such an analysis suggests that the second stable conformer takes a gauche form rather than the s-cis. To increase the number of reliable data to be used in this study, the infrared and Raman spectra of the d0, 1,1,4,4-d4, and d6 species were observed in low-temperature Ar matrices. The infrared spectra of the second stable conformer were also observed using a combination of the high-temperature nozzle and low-temperature matrix techniques.
A Model of Nematic Liquid Crystals for Viscosity and Self-diffusion
Authors: Miyajima Seiichi , Nakamura Nobuo , Chihara Hideaki 
Published: July 2006

Abstract
A Geometrical model is presented which rationalizes the viscosity and self-diffusion coefficients and their anisotrcpies in nematic liquid crystals. The model is an extension of Eyring’s theory of the liquid state to the anisotropic fluid, based on the geometry of the constituent molecule. A novel concept, effective anisotropy factor of a molecule, is introduced which is determined from the viscosity coefficients. An empirical law on the principal viscosity coefficients by Kneppe et al. is given its molecular basis by this model. Self-diffusion coefficient tensor calculated from the available viscosity data of PAA, MBBA, and HBAB agree well with experiment.