bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reaction of Phenylacetonitriles with Benzaldehydes in Hexamethylphosphoric Triamide Solution Containing the Sodium Salt of α,α-Dimethylbenzyl Hydroperoxide
Authors: Takahashi Kazumasa , Yamada Kazutoshi , Iida Hirotada 
Published: July 2006

Abstract
Treatment of phenylacetonitriles with p-substituted benzaldehydes in hexamethylphosphoric triamide solution containing the sodium salt of α,α-dimethylbenzyl hydroperoxide gave α-benzoyl-α-phenylacetamides as major products.
The Photochemical SO Extrusion of 2,2,4,4-Tetraacylthietane 1-Oxides
Authors: Ito Shoei , Mori Jun-ichi 
Published: July 2006

Abstract
The irradiation of a benzene solution of 2,2,4,4-tetraacylthietane 1-oxides, which had been prepared from dimedone-aldehyde derivatives with SCl2, followed by oxidation with peracid, was carried out to give the corresponding 1,1,2,2-tetraacylcylopropanes(4) or a mixture of 4 and the corresponding dihydrofuran derivative, depending on the C3 substituent on the 1-oxides and wavelength.
The σ-Bonded Palladium(II) Complexes of 4-Chromanone Oxime Derivatives
Authors: Izumi Taeko , Katou Takao , Kasahara Akira , Hanaya Kaoru 
Published: July 2006

Abstract
In the presence of sodium acetate, the reaction of 4-chromanone oxime with lithium tetrachloropalladate(II) affords an ortho-palladated binuclear complex. The reaction of the complex with carbon monoxide in methanol was also examined.
Electronic Spectra and Electronic Structures of a Series of Bisdehydroannulenes
Authors: Tanaka Jiro , Tanaka Masashi , Morita Masaharu , Nakagawa Masazumi , Iyoda Masahiko 
Published: July 2006

Abstract
Electronic absorption spectra of tetra-t-butylbisdehydro[14], [18], [22], [26], and [30]annulenes were investigated experimentally and theoretically. SCF MO calculations were carried out by the P-P-P method and random phase approximation (RPA). An assignment of spectra is presented. Fluorescence excitation polarization spectra of tetra-t-butylbisdehydro[14]annulene and the crystalline reflection spectra of tetra-t-butylbisdehydro[18]annulene were studied in order to determine the polarization of the spectra. The assignment was confirmed by these methods.
Solution Properties of Phycocyanin. V. Studies of the Self-association Reaction of Phycocyanin in a pH 5.4 Solution
Authors: Saito Takahide , Iso Naomichi , Mizuno Haruo , Kitamura Ichiro 
Published: July 2006

Abstract
The self-association of phycocyanin in a buffer solution of pH 5.4 with an ionic strength of 0.1 has been studied by sedimentation equilibrium measurements in the temperature range from 5.0 to 25.0 °C. The thermodynamical treatment is also presented. The self-association of phycocyanin molecules proceeds with a decrease in the temperature. The concentration dependence of the apparent weight-average molecular weight of phycocyanin is interpreted in terms of a monomer\ightleftharpoonshexamer equilibrium system. It is clear from the thermodynamic parameters, ΔG0, ΔH0, and ΔS0, that the self-association reaction is spontaneous in the solution of pH 5.4. In the association process, the formation of hydrophobic bonds is suggested by the large positive entropy change accompanying association reaction of phycocyanin molecules.
Studies on the Ammonium Form of Crystalline Zirconium Phosphate. III. Ammonium–Hydrogen Ion-exchange on α-Zirconium Phosphate Prepared by the Direct Precipitation Method
Authors: Hasegawa Yoshitsugu , Kuwayama Motomasa 
Published: July 2006

Abstract
The ammonium–hydrogen ion-exchange on α-zirconium phosphate prepared by the direct precipitation method has been investigated by means of pH titration and X-ray diffractometry. In the forward process (α-zirconium phosphate to the ammonium form) the ion-exchange reaction took place in one stage at the equilibrium pH of 5.9–6.0 and the α-zirconium phosphate exchanger was directly converted into the ammonium form. In the reverse process (the ammonium form to α-zirconium phosphate) the reaction proceeded in three stages, that is, the ammonium form→ a half-exchanged form→ an intermediate form→α-zirconium phosphate. The chemical composition of the half-exchanged form has been represented as Zr(NH4PO4)(HPO4)·nH2O (n&gt;0.5). A small amount of ammonium ions in the exchanger could not be easily replaced with protons in the solution.
Photometric Determination of a Trace Amount of Nitrite by Its Kinetic Effect
Authors: Utsumi Satori , Okutani Tadao , Sakuragawa Akio , Kenmotsu Akira 
Published: July 2006

Abstract
A new photometric method has been developed for determining nitrite ions. This method is based on the kinetic effect of nitrite ions on the color-fading of the iron(III) thiocyanate complex in dilute nitric acid solution in the presence of iodide ions. The reaction is initiated by adding an ammonium iron(III) sulfate solution to the sample solution containing a mixture of potassium thiocyanate and potassium iodide at 25 °C. A concentration of nitrite ions, ranging from 0.0005 to 10 ppm can be determined by measuring the absorbance at 460 nm at a given time after the initiation using four appropriate calibration curves. Silver, mercury(II), iron(II), sulfide, sulfite, thiosulfate, chromate and cyanide ions in the concentration range from 0.1 to 1 ppm level interfered with the determination.
Circular Dichroism Spectra of Cobalt(III) Complexes of the [Co(O,O)2(N)2]−-Type
Authors: Muramoto Satoru , Kawase Kenji , Shibata Muraji 
Published: July 2006

Abstract
The [Co(O,O)2(N)2]−-type complexes, [Co(ox)(mal)(en)]−, cis-[Co(CO3)(mal)(NH3)2]−, cis-[Co(ox)(mal)(NH3)2]− and cis-[Co(mal)2(NH3)2]−, have been prepared and resolved. The CD spectra of various complexes of this type including these new complexes have been measured. The assignments of the absolute configurations have been carried out by means of the CD comparison. The CD patterns in the first absorption band region have revealed regular change with the varied O,O ligands (O,O=CO32−, ox2−, and mal2−), and from this fact a criterion for the assignments of the absolute configurations for the complexes of the present type has been established.
On the Behavior of Mercury in Some Polluted Seawater
Authors: Matsunaga Katsuhiko , Tsujioku Hiroaki , Fukasa Sigeru , Hasebe Kiyoshi 
Published: July 2006

Abstract
Most of the mercury in coastal seawater polluted with waste water including mainly organic suspended matter is associated with suspended matter, especially particulate organic matter. The amount of mercury adsorbed on a given amount of particulate organic matter nearly obeys Freundlich’s adsorption isotherm at mercury concentrations less than 15 ppm in particulate organic matter. The mercury in suspended matter is not much reduced by the addition of tin(II) chloride. Thus, to get the total value of the mercury concentration, the water samples must be heated with the addition of a sulfuric and nitric acid mixture to decompose the suspended matter.
Nickel(II) Complexes of Schiff Bases Derived from Salicylaldehyde and Glycyl-aspartate or -glutamate. Application to a Selective Hydrolysis Reaction of Dimethyl Glycylaspartate and Glycylglutamate
Authors: Nakao Yasuo , Nakahara Akitsugu 
Published: July 2006

Abstract
Nickel(II) complexes of Schiff bases derived from salicylaldehyde and glycylaspartate or glycylglutamate were prepared and their structures were determined on the basis of electronic absorption and 1H NMR spectra. The relationship between structure of the chelates and stability of fused-ring systems was discussed in some detail, and was applied to a selective hydrolysis reaction of dimethyl glycylaspartate and glycylglutamate. Nickel(II) complexes of Schiff bases derived from salicylaldehyde and β-methyl glycylaspartate or γ-methyl glycylglutamate were obtained by a reaction between dimethyl glycylaspartate or glycylglutamate and bis(salicylaldehydato)nickel(II) in methanol containing sodium or potassium hydroxide.
Kinetics and Mechanism of the Oxidation Reaction of Bis(μ-dibutyldithiocarbamato-S,S′)-digold(I) by Halogens
Authors: Kita Hidetoshi , Itoh Kazuyuki , Tanaka Koji , Tanaka Toshio 
Published: July 2006

Abstract
Kinetics of the reaction of bis(μ-dibutyldithiocarbamato-S,S′)-digold(I), [Au(n-Bu2dtc)]2, with I2, IBr, and Br2 in dichloromethane was studied by the stopped-flow technique. A 1 : 1 charge-transfer (CT) complex, [Au(n-Bu2dtc)]2·X2 (X2=I2, IBr, and Br2), formed in the initial process of reaction was identified spectrophotometrically at −50 °C. The rates of reaction were almost the same for I2, IBr, and Br2, and independent of the both [Au(n-Bu2dtc)]2 and halogen concentrations. The reaction has been interpreted to proceed via the charge-transfer complex, [Au(n-Bu2dtc)]2·X2, which decomposes in a rate-determining step to give the final product, [AuIII(n-Bu2dtc)2][AuIX2]. The activation parameters for the reactions were determined: ΔH\eweq(kJ/mol)=43.7 (I2), 26.0 (IBr), and 12.3 (Br2); ΔS\eweq(J/mol K))=−91.5 (I2), −156 (IBr), and −201 (Br2).
Crystal Structure and Absolute Configuration of (+)546-cis(O)-Triammine-(sarcosinate-N-propionato)cobalt(III) (+)546-(Ethylenediamine-tetraacetato)cobaltate(III) Monohydrate
Authors: Okamoto Ken-ichi , Tsukihara Tomitake , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
The crystal structure of (+)546-cis(O)-triammine(sarcosinate-N-propionato)cobalt(III) (+)546-ethylenediaminetetraacetato)cobaltate(III) monohydrate was solved by single crystal X-ray diffraction techniques. The crystal is orthorhombic, space group P212121, with a=10.792, b=26.816, c=8.203 Å, and Z=4. The final R value was 0.054. The absolute configurations of two complex ions were determined by means of anomalous dispersion using Cu Kα radiation. The coordinated asymmetric nitrogen atom of sarcosinate-N-propionate ligand takes an R configuration, and the (+)546-(ethylenediaminetetraacetato)cobaltate(III) ion Δ one.
Study of the Quasi-pcaks in the Ion Cyclotron Double Resonance
Authors: Aoyagi Katsuyuki 
Published: July 2006

Abstract
Quasi-peaks which do not correspond to any reactant ion in the ion-molecule reaction were observed in the ion cyclotron double-resonance spectrum. The field-sweep quasi-ICDR spectrum was also observed. Expressions giving the frequencies of the quasi-peaks observed in the ion cyclotron double-resonance spectrum were obtained; the results agreed with those obtained previously. Both the ion mass and ion drift-voltage dependences of the quasi-peaks were shown. A close agreement between the calculated and measured values was obtained. A method to repress the quasi-peaks is discussed.
Chemical Transformation of Seldomycin 5 into 3′-Deoxyseldomycin 5 and Related Compounds
Authors: Matsushima Hideo , Mori Yasuki , Kitaura Kozo 
Published: July 2006

Abstract
3′-Deoxyseldomycin 5 (2), 2′-deamino-3′-epiamino-3′-deoxyseldomycin 5 (14), and 2′,3′-epimino-2′-deamino-3′-deoxyseldomycin 5 (15) were prepared from seldomycin 5 (1). Treatment of hexa-N-ethoxycarbonyl (ecb)-3′-O-tosylseldomycin 5 with sodium borohydride in DMSO gave the corresponding N-ecb-derivatives of 2, 14, and 15. Removal of the ecb groups of these compounds with aq potassium hydroxide gave the free bases 2, 14, and 15, respectively. Structure determination of the products was performed by means of MS, CMR, PMR, and chemical reactions. It was found that 2 exhibits a more potent and broader antibacterial activity than the parent compound 1, and 14 shows unique antibacterial spectrum against resistant strains, whereas 15 has almost no activity.
Enantioface-Differentiating (Asymmetric) Hydrogenation of β-Ketoester with Modified Raney Nickel Catalyst (MRNi). XXXI. A Comparative Study of Reaction Rates and Optical Yields
Authors: Ozaki Hiroshi , Tai Akira , Kobatake Shinzo , Watanabe Hironobu , Izumi Yoshiharu 
Published: July 2006

Abstract
Enantioface-differentiating hydrogenations of methyl acetoacetate over (S)-alanine-, (S)-2-aminobutyric acid, (S)-valine-, (S)-leucine-, (S) -malic acid-, and (R,R)-tartaric acid-MRNi were carried out under atmospheric pressure of hydrogen and the effects of the modifying reagent on the rates of the formation of enantiomer, vS and vR, were investigated. The rates of hydrogenation, v=vS+vR, were the same for all the amino acid-MRNi and also for all the hydroxy dicarboxylic acid-MRNi. However, the vR⁄vs ratios were different. These results are explained in terms of the independence of the rate-determining and enantioface-differentiating steps in the reaction pathway of hydrogenation. The rate-determining step of hydrogenation was shown to be the hydrogen addition to the adsorbed substrate, while the enantioface-differentiating step was expected to occur prior to the rate-determining step.
Studies of the Azulenes. V. Condensation Products of Guaiazulene and 4,6,8-Trimethylazulene with Active Methylene Compounds by Means of Selenium Dioxide. Molecular Asymmetry Induced by Chelate Ring and Its Anisotropy Effect
Authors: Kohara Kazuko 
Published: July 2006

Abstract
In the presence of selenium dioxide, guaiazulene and 4,6,8-trimethylazulene condensed with the active methylene compounds, ethyl acetoacetate and acetylacetone, to give ethyl α-(3-guaiazulenyl)acetoacetate (3a), α-(3-guaiazulenyl)acetylacetone, ethyl α-(4,6,8-trimethyl-1-azulenyl)acetoacetate (5a), and α-(4,6,8-trimethyl-1-azulenyl) acetylacetone. These α-substituted β-diketones exist exclusively in their corresponding enol forms, as evidenced by their NMR spectra. In the NMR spectra of 3a and 5a, the ethyl protons of the ester group show an ABX3 pattern; the observed nonequivalence of the methylene protons is attributable to the restricted rotation between azulene and the substituent carbon atoms. From an inspection of the chemical shifts of the methyl group of metal chelate compounds of azulene derivatives, it is now reasonably concluded that there is no aromaticity associated with the chelate ring, providing further support for Musso’s proposal.
Stark Effect on the Electronic Bands of a Symmetric-top Molecule
Authors: Amako Yoshito , Sato Yoshi-ichi , Watanabe Akiyoshi 
Published: July 2006

Abstract
Calculations have been performed on the energy matrix of a rigid symmetric-top molecule, HCHO, in order to determine the transition energies and intensities of the rotational sub-bands of the electronic spectrum under various magnitudes of external electrostatic fields. Though HCHO is an asymmetric-top molecule, the rotational structure of the 3390 Å band of this molecule is close to that of a perpendicular band of a symmetric-top molecule, at least, for not too small values of K. The variation in the band structures with the applied fields can be illustrated by the behavior of several selected bands, pP, pQ, rR, and rQ. Below 100 kV/cm, the overall Stark splittings have been linearly dependent on the field strength, regardless of the branch types. Over 100 kV/cm, however, a deviation from the linear dependence has been found for a certain branch. Changes in the band shape have appeared at such small values of external fields that no deviation from the linear field dependence of the overall Stark splitting has been observed. Such changes are dependent on the branch types, especially in the cases of branches with small J values and with K&lt;J. The intensity enhancement of some forbidden bands has also been observed, the magnitude of which is proportional to the square of the field strength below 100 kV/cm. However, the relation between the intensity enhancement and the electric fields has been found to be complicated at fields over 100 kV/cm, the enhanced intensity being proportional to a coupled sum of E2 and higher terms. At a fixed electric field, a linear relation has been found between the overall Stark splitting and the various μ values assumed for the excited state. The analysis of the data has enabled us to determine the electric dipole moment of the lowest n→π* excited state of HCHO as 1.65 D.
Study on Zinc O,O-Diisobutyl Dithiophosphate as Antioxidant
Authors: Ohkatsu Yasukazu , Kikkawa Kazumi , Osa Tetsuo 
Published: July 2006

Abstract
Cumyl hydroperoxide has been decomposed using zinc O,O-diisobutyl dithiophosphate. The decomposition reaction consisted of three stages including the first homolytic decomposition and the last heterolytic decomposition. These decomposition modes depended considerably on the relative concentration of the complex to the hydroperoxide and the total concentration. From these results and on the basis of decomposition reaction in the presence of both zinc O,O-diisobutyl dithiophosphate and bis(O,O-diisobutoxyphosphonothioyl) disulfide, it has been shown that the formation of sulfuric acid was most important for heterolytic decomposition.
Preparation of Alkylthio- and Phenylthio(triphenylphosphine)copper(I) Complexes and Their Catalytic Activity for Transesterification of S-Alkyl Ethanethioates and Thiols
Authors: Kubota Minoru , Yamamoto Akio 
Published: July 2006

Abstract
Alkylcopper complexes, RCu(PPh3)2 (R=methyl, ethyl, propyl, isobutyl)reacted with sulfur smoothly at low temperatures to produce dialkyl disulfides. This indicates the insertion of sulfur to alkyl-Cu bond taking place followed by coupling of the two alkylthio–Cu bonds. Methylcopper complex, CH3Cu(PPh3)2·0.5Et2O reacted with thiols to produce alkylthio- and phenylthiocopper complexes having one or two triphenylphosphine ligands. The reactions of these alkylthiocopper complexes with acyl halides and acid anhydrides produced S-alkyl ethanethioates in high yields, whereas the reactions of alkylthiocopper complexes with alkyl halides produced dialkyl sulfides. Alkylthio- and phenylthiocopper complexes were found to catalyze the transesterification reactions between S-alkyl ethanethioates and thiols. The exchange reactions also take place between the alkylthiocopper complex and benzenethiol producing phenylthiocopper complex with liberation of alkanethiol.
The Hydrocracking of Alkyl-substituted Polynuclear Aromatic Hydrocarbons over ZnCl2/CuCl Molten Salt Catalyst
Authors: Nakatsuji Yohji , Ikkaku Yasuhiko , Nomura Masakatsu , Kikkawa Sh\={o}ichi 
Published: July 2006

Abstract
The hydrocracking of alkyl derivatives of polynuclear aromatic hydrocarbons (naphthalene, anthracene, dihydroanthracene, phenanthrene, and dihydrophenanthrene) over ZnCl2/CuCl molten salt was examined at 400 °C for 3 h in a batch autoclave system. The kinds of alkyl groups, the positions of the alkyl groups, and the types of condensed rings were changed in order to clarify the decomposition process of the polynuclear aromatic hydrocarbons. On the basis of the detailed product distribution obtained by using GC-MS, the behavior of the alkyl group attached to the condensed ring under these reaction conditions was found to be different. Generally, in this investigation, the alkyl group was not completely dealkylated in the initial stage and remained in the products as monocyclic aromatics; the extent of dealkylation was found to be dependent upon the type of starting materials. In the hydrocracking of 9,10-dihydroanthracene, dehydrogenation occurred in preference to the opening of the central ring.
The Reaction of Thio-substituted Cyclopropenium Ions with Iminopyridinium and Sulfonium Ylides
Authors: Inoue Shinichi , Yasuda Gorou , Hori Takuya 
Published: July 2006

Abstract
The reaction of several thio-substituted cyclopropenium ions with iminopyridinium and sulfonium ylides in organic solvents at reflux and room temperature under N2 gave N,N′-dicyclopropenylidene urea derivatives, together with some unidentified compounds.
Reactions of Benzyl 2-Benzyloxycarbonylamino-2-deoxy-3-O-mesyl-α-d-gluco- and -α-d-allopyranoside Derivative with Iodide
Authors: Sano Hiroshi , Iimura Seiji , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
The reactions of benzyl 4,6-O-benzylidene-2-benzyloxycarbonylamino-2-deoxy-3-O-mesyl-α-d-glucopyranoside (1), its N-methyl derivative (4) and 3-epimer (8) with sodium iodide in DMF were studied. Compound 1 gave several products including 2,3-alloepimine, 4 an oxazolidinone and 8 a 3-iodo derivative.
Cyclohexadienyl Radicals in γ-Irradiated catena-μ-Ethylenedi aminecadmium(II) catena-Tetra-μ-cyanomercurate(II)–Benzene (1/2) and the Analogous Clathrates
Authors: Iwamoto Toschitake , Kiyoki Mamoru , Matsuura Niro 
Published: July 2006

Abstract
Cyclohexadienyl radicals produced by γ-ray irradiation are thermally stable up to 423 K in the mother benzene clathrates Cd(en)Hg(CN)4·2C6H6, Cd(en)Cd(CN)4·2C6H6, Cd(tn)Hg(CN)4·2C6H6, and Cd(NH3)2Hg(CN)4· 2C6H6. However, no thermally stable C6H7· radicals have been observed in Cd(NH3)2Ni(CN)4· 2C6H6 and Cd(en)Ni(CN)4·2C6H6 even immediately after irradiation. The ESR spectra of C6H7· show the hyperfine splitting constants of the methylene, para, ortho, and meta protons 48, 13, 9, and 3 G, respectively.
The Construction of an Energy-dispersive X-Ray Diffractometer for Liquids and Its Application to CCl4
Authors: Murata Yoshitada , Nishikawa Keiko 
Published: July 2006

Abstract
An energy-dispersive X-ray diffractometer using a solid-state detector is constructed for the determination of the liquid structure. It has two merits over the usual angle-dispersive diffractometer, i.e., a higher resolution of the s-value and a wider measurable s-region. The procedure of the data analysis and the results for liquid CCl4 are described. The absorption correction is important in the reflection method. By taking advantage of the energy-dispersive method, it is shown that liquid CCl4 has a long-range correlation at room temperature.
The Molecular Sieving Action of Ion-exchanged Zeolites A
Authors: Ohgushi Tatsuo , Yusa Atsushi , Kinoshita Kunio , Yatsurugi Yoshifumi 
Published: July 2006

Abstract
K12-A zeolite was ion-exchanged with Mg2+, Mn2+, Co2+, Cd2+, or Pb2+, and molecular sieving properties of the resultant zeolites were studied, mainly for PH3 and SiH4. (K, Mg)-A and (K, Mn)-A adsorbed PH3 but not SiH4, and hence are usable as a purifier for SiH4. (K, Co)-A, (K, Cd)-A, and (K, Pb)-A decomposed both PH3 and SiH4, and are unsuitable as an adsorption purifier for SiH4. By using adsorption columns containing (K, Mn)-A or (K, Mg)-A, breakthrough curves were obtained for PH3 in SiH4. The breakthroughs of (K, Zn)-A and (K, Ca)-A columns were also measured for comparison. The breakthrough point increased in the order of (K, Ca)-A&lt;(K, Mg)-A&lt;(K, Mn)-A&lt;(K, Zn)-A. The mechanism of the molecular sieving is discussed. It is concluded that introduced bivalent cations increase the Debye-Waller factor of K+ blocking the windows. A large Debye-Waller factor causes a decrease in the activation energy required for adsorbate molecule to pass through the blocked window.
ESR Spectra of Bis(acetylacetonato)oxovanadium(IV) and Related Chelates in Molten o-Terphenyl and Some Other Organic Compounds
Authors: Matsunaga Yoshio 
Published: July 2006

Abstract
All the patterns from the isotropic ESR spectrum to the anisotropic one of bis(acetylacetonato)oxovanadium(IV) and related chelates are recorded by employing molten o-terphenyl as a solvent and by changing the temperature above and below the melting point. The results are qualitatively explained in terms of the anisotropic molecular motion and are considered to be evidence for the presence of clusters in the melt. Similar observations are made with some derivatives of 2,4,6-trinitrodiphenylamine, but only partially with m-terphenyl and the 3′-methoxy and 3′-ethoxy derivatives of 2,4-dinitrodiphenylamine. The implications of the results concerning the structure of the melts are discussed.