bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Tengerite Type Rare Earth Carbonates
Authors: Wakita Hisanobu , Nagashima Kozo 
Published: July 2006

Abstract
Rare earth carbonates which give the same X-ray powder diffraction pattern as tengerite were prepared by heating aqueous solutions containing rare earth chlorides and ammonium trichloroacetate. Y, Er, Ho, and Gd gavee xactly the same X-ray powder pattern as tengerite, while Nd and Sm were similar to tengerite but with a few additional diffractions. X-ray powder data of the tengerite type rare earth carbonate were indexed and cell parameters of a0=9.20±0.02 Å, b0=11.32±0.03 Å, and c0=7.59±0.01 Å for Y2(CO3)3·nH2O (n=2–3), with 4 moles of formula units per cell and orthorhombic symmetry were established. Linear correlations were demonstrated between refractive indices or cell parameters of the synthesized carbonates and their respective rare earth element atomic numbers.
Preparation and Circular Dichroism Spectra of Bis(aminoacidato)ethylenediaminecobalt(III) Complexes
Authors: Matsuoka Nobuko , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Cis(O) and trans(O) complexes of bis(l-serinato)ethylenediaminecobalt(III) ion have been prepared and completely separated into six possible isomers by ion-exchange column chromatography. These isomers have been assigned to Λ-trans(O), Δ-trans(O), Λ-C2-cis(O), Δ-C1-cis(O), Λ-C1-cis(O) and Δ-C2-cis(O) in the elution order, on the basis of their absorption and circular dichroism spectra. Trans(O)- and C1-cis(O)-bis(glycinato)ethylenediaminecobalt(III) complexes have been resolved into their optically active isomers, and trans(O)-bis(l-alaninato)ethylenediaminecobalt(III) ion has been prepared and separated into two configurationally active isomers. The absorption and circular dichroism data of six isomers of [Co(l-ser)2en]+, two isomers of [Co(l-ala)2en]+ and two isomers of [Co(gly)2en]+ have been discussed in being compared with those of the corresponding isomers of oxalatobis(l-serinato)cobaltate(III) complex.
Ring Expansion through a 1,3-Acyl Rearrangement. Reactions of Cyclic Sulfonium Ylides with Acetylenic Compounds
Authors: Higo Moriaki , Sakashita Takeshi , Toyoda Minoru , Mukaiyama Teruaki 
Published: July 2006

Abstract
Ring expansion of cyclic sulfonium ylides with acetylenic compounds was investigated. It was found that a six-membered cyclic sulfonium ylide (I) gave eight-membered ring expansion products (IIIa—e) in high yields under mild conditions on treatment with acetylenic compounds (IIa—e) in dimethyl sulfoxide. In a similar manner, the reactions of five- and seven-membered cyclic sulonium ylides with II afforded ring expansion products (XIa) and (IXa—c). The ring expansion was considered to proceed through an intramolecular 1,3-acylrearrangement. It was found that, when the reaction of I and IIIa was carried out in benzene, an intermediate bicyclic sulfonium betaine (VIIa) was obtained as yellow precipitates. The properties and reactions of VIIa were investigated. It was shown that the ring expansion product IIIa gave cyclooctenone derivatives (XIIIa—c) by the reaction with some nucleophiles. IIIa was found to give diene esters (XIII, R=acyl)and diene ethers (XIII,R=alkyl) upon reaction with acyl and alkyl halides.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XXIV. The Effect of Unsaturated Compounds on the Asymmetric Activity of the Catalyst
Authors: Ninomiya Toshio 
Published: July 2006

Abstract
Dehydroacetic acid and methyl cis-3-acetoxycrotonate were picked out as trace impurities of the substrate, methyl acetoacetate. The effects of dehydroacetic acid, methyl cis-3-acetoxycrotonate, and diketene, which is the starting material for the preparation of methyl acetoacetate, on the asymmetric activities of catalysts modified with l-amino acids were examined in the hydrogenation of methyl acetoacetate. The above three compounds, when added to the hydrogenation system, raised the asymmetric activity of the catalyst. Also, simple unsaturated compounds, such as acetone and diethyl maleate, has a similar effect on the catalyst. The effects of the above unsaturated compounds on the asymmetric activities of the catalysts modified with l-amino acids were discussed, and it was suggested that the unsaturated compounds adsorb on the catalyst surface and might scavenge the asymmetrically uncontrolled active hydrogen absorbed on the catalyst surface.
β-(2,4,6-Cycloheptatrien-1-yl)ethylcarbene. The Synthesis of 9-Substituted Bicyclo[4.2.1]nona-2,4,7-trienes and 9-Substituted Barbaralanes
Authors: Tsuruta Haruki , Kurabayashi Katsuhiko , Mukai Toshio 
Published: July 2006

Abstract
The thermal decomposition of sodium salt of (2,4,6-cycloheptatrien-1-yl)acetaldehydes tosylhydrazone (4, 6, and 8) afforded 9-substituted bicyclo[4.2.1]nona-2,4,7-triene (9, 11, and 14) and 9-substituted barbaralane (10, 12, and 15). In the case of 8, products containing two nitrogen atoms (17 and 18) were isolated. The structure and the photochemical reaction of 17 provided strong support for the intermediacy of the tetracyclo[4.3.0.02,9.05,7]-nona-3-ene (37) derivative for the formation of the bicyclo[4.2.1]nona-2,4,7-triene derivatives. The difference in energy surface between C9H10 and C10H10 hydrocarbons was discussed.
1,2: 8,9-Dibenzo-3,10-bisdehydro[14]annulene-5,12-dione
Authors: Kojima Takashi , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
An annelated[14]annulenedione (V) was prepared by the Castro reaction of cuprous salt of o-iodocinnamoylacetylene (IV) in order to examine the aromatic character of the inner fourteen membered ring. The NMR spectra of V in arsenic trichloride and deuterotrifluoroacetic acid suggest that significant downfield shift of the inner protons HB is due to a paramagnetic ring current arising from polarization of two carbonyl groups in the inner ring, compared with the spectra of a reference compound VI.
Studies on Aminosugars. XXIX. The Synthesis of 3′-O-Methylkanamycin
Authors: Umezawa Hamao , Tsuchiya Tsutomu , Muto Ryujiro , Umezawa Sumio 
Published: July 2006

Abstract
6-O-(3-Amino-3-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine, previously synthesized, was masked with ethoxycarbonyl, isopropylidene, and benzyl groups to give 6-O-(2-O-benzyl-3-deoxy-3-ethoxycarbonylamino-4,6-O-isopropylidene-α-d-glucopyranosyl)-N,N′-diethoxycarbonyl-2-deoxystreptaniine, which was condensed with 6-azido-2,4-di-O-benzyl-6-deoxy-3-O-methyl-α-d-glucopyranosyl chloride by a modified Koenigs-Knorr reaction to give a mixture of α,α- and α,β-diglycoside compounds. Hydrogenation of the azido group and removal of the masking groups gave a mixture of 3′-O-methylkanamycin and its diastereomer. The 3′-O-methylkanamycin was devoid of antibacterial activity.
The Constituents of Hops (Humulus lupulus L.). VII. The Rapid Analysis of Volatile Components
Authors: Naya Yoko , Kotake Munio 
Published: July 2006

Abstract
The volatile constituents from several varieties of Hops have been investigated by the direct loading of fresh plant tissue through GC-MS. The Saaz variety was distinguished among the examined varieties by its high content of β-farnesene. Hallertau was characterized by a low content of myrcene and a high content of humulenes. Shinshu-wase differed in its high content of myrcene and its low content of humulenes. Northern Brewer was rather close to Hallertau, whereas Yakima appeared to be closely related to Shinshu-wase. The myrcene content of hop oil was observed to correlate competitively with the total amount of humulenes, caryophyllene, and farnesene. 2-Methylbutyl isobutyrate accumulates in company with myrcene. The biosynthetic implication of these relationships have been briefly discussed.
Shapes of Fundamental Bands of Liquid Carbon Disulfide, Vibrational and Reorientational Relaxations
Authors: Kakimoto Masao , Fujiyama Tsunetake 
Published: July 2006

Abstract
The shapes and intensities of the fundamental bands, v2 (the CSC bending) and v3 (the C–S antisymmetric stretching), were measured for liquid carbon disulfide and its chloroform solutions. The intensity data were corrected for the effect of the dielectric field at each frequency. The analyses of the v2 and v3 bands indicate that the band-widths of liquid carbon disulfide can not be explained only in terms of reorientational relaxation. It is also shown that the vibrational relaxation of the resonance type can well explain the concentration dependence of the observed band-widths. The magnitudes of the vibrational and reorientational relaxations obtained from the bandshape analyses are given. It is emphasized that the measurement of the absolute intensity is indispensable for the analyses of the infrared-band shapes of condensed phases.
Computer Simulations of the ESR Spectra of the Triplet Dimers of Bis-(N-Salicylidenemethylaminato)copper(II) in Toluene
Authors: Ghikira Makoto , Isobe Taro 
Published: July 2006

Abstract
It has been concluded, from computer simulations of the observed ESR line shapes, that the dimeric structure of bis- (N-salicylidenemethylaminato)copper(II) in a frozen toluene solution is similar to that in its γ-form crystals. Furthermore, the difference between the hyperfine splittings observed at both edges of the triplet spectra for ΔM=1, the large frequency dependence of the fine-structure splitting, and the additional hyperfine structures observed in the field range between the so-called low-field parallel and perpendicular lines have been found to be due to the noncoincidence of the principal axes of the g tensor with those of the fine-structure tensor.
The Photolysis of Ethoxycarbonylmethyltriphenylphosphonium Salts
Authors: Nagao Yoshihiro , Shima Kensuke , Sakurai Hiroshi 
Published: July 2006

Abstract
Irradiation of ethoxycarbonylmethyltriphenylphosphonium salts (IV) gave products expected to be derived from the homolytic fission of the P–CH2CO2Et or P–Ph bond. The rate of the product formation was dependent strongly on the anion species and on the solvent polarity; an oxidizable anion was effective for the photolysis and the less polar the solvent the faster the rate became. It was found through the measurement of the electrical conductance that the degree of electrolytic dissociation of IV was very low at the concentration employed in the photolysis. On the basis of these results, the photolysis of IV was confirmed to proceed through a direct charge transfer from an anion to a cation.
The Singlet-triplet Absorption Spectra of Heterocyclic Amine N-Oxides (I)
Authors: Kubota Tanekazu , Yamakawa Masumi , Mizuno Yoshiko 
Published: July 2006

Abstract
The singlet-triplet absorption (T1←N) spectra of pyridine N-oxide, quinoline N-oxide, isoquinoline N-oxide, and acridine N-oxide have been observed by applying the oxygen-intensification technique. The correlation between the T1←N absorption bands and the singlet-singlet (S*←N) absorption bands of these N-oxides has been established and discussed theoretically. The lowest triplet state of the N-oxides has been assigned as the π-π* transition of a 3La (CT) nature. The T1←N absorption bands obtained show a blue shift in polar solvents. The results have been compared with the case of S*←N transitions and have been reasonably explained by taking into account the contribution from the intramolecular charge transfer.
Comparison of the Electronic Spectra of Geometric Isomers. III. β-Substituted Styrenes
Authors: Fueno Takayuki , Yamaguchi Kizashi , Naka Yuji 
Published: July 2006

Abstract
The ultraviolet absorption spectra of cis and trans isomers of various β-substituted styrenes have been measured both in the gaseous state and in n-hexane solution. The excitation energies observed for cis isomers are either smaller or greater than those of the trans, depending on the type of β-substituents. The isomeric difference in the energy of the lowest allowed transition was found to be linearly correlated with Taft’s steric substituent constants. The electronic states of the various isomeric pairs were calculated by the LCAO–SCF–CI method of the Pariser-Parr-Pople type. The results were found to be entirely in line with the observed spectral features.
A Computer Simulation of the Oxidation Mechanism. The Liquid-phase Oxidation of Cumene Catalyzed by Triphenylsulfonium Chloride
Authors: Ohkubo Katsutoshi , Hashimoto Tohru 
Published: July 2006

Abstract
The mechanism of the liquid-phase oxidation of cumene (RH) catalyzed by triphenylsulfonium chloride was investigated by the computer simulation on the basis of the kinetic analysis. We will discuss particularly the initial short stage of the reaction through the time-conversions of the concentrations of components produced or consumed: R·, RO2·, ROOH, a complex between the catalyst and O2 (Cat.–O2), etc. We determined the values of the rate constants appearing in the reaction steps with a good analytic fit to the experimental results, together with the activation energies of all the reaction steps. The following relationships were found between the initial rate of the component formation, ri (component), and the initial concentration of reactants ((Cat.)i, (RH)i, and (O2)i):
ri(Cat.–O2)\simeq1.243×10−2(Cat.)i0.970(RH)i0.0(O2)i0.964 mol⁄l·min
ri(R·)\simeq4.705×10−12(Cat.)i0.648(RH)i1.886(O2)i−0.422 mol⁄l·min
ri(RO2·)\simeq5.837×10−12(Cat.)i0.316(RH)i0.509(O2)i0.737 mol⁄l·min
ri(ROOH)\simeq4.860×10−4(Cat.)i0.436(RH)i1.842(O2)i−0.850 mol⁄l·min
Electrical and Optical Properties of the Iodine Complexes of Phenoxazine, Phenoselenazine, and Benzophenothiazines
Authors: Matsunaga Yoshio , Suzuki Yukio 
Published: July 2006

Abstract
The electrical resistivities and Seebeck coefficients of the 2 : 3 iodine complexes of phenoxazine, phenoselenazine, and benzophenothiazines were measured as a function of the temperature. They have resistivity values at 20°C ranging from 10 ohm·cm for the phenoxazine complex to 34 ohm·cm for the benzo[a]phenothiazine complex. Employing the equation of Johnson and Lark-Horowitz for the Seebeck coefficient of an intrinsic semiconductor, the ratio of the electron-to-hole mobility in the phenoselenazine complex was found to be 1.07 and the electron mobility was estimated as 0.26 cm2/V sec. By an examination of the vibrational spectra, the expected cation-radical character was confirmed for the complexes of phenoselenazine and benzophenothiazines. The presence of a broad electronic absorption band in the rock-salt region characteristic of low-resistivity organic semiconductors was noted in every case.
The Resonance Raman Spectrum of the Poly(vinyl alcohol)-Iodine Complex
Authors: Inagaki Fuyuhiko , Harada Issei , Shimanouchi Takehiko , Tasumi Mitsuo 
Published: July 2006

Abstract
The resonance Raman spectra were observed from dilute aqueous solutions of the poly (vinyl alcohol)-iodine complex, using the He–Ne 632.8 run and Ar+ ion 488.0 nm lines for excitation. Two kinds of poly (vinyl alcohol) were used; one (A) had the degree of polymerization of 500, and the other, (B) 2000. For both samples, the resonance Raman spectra taken with the 632.8 nm line are similar to that of the starch-iodine complex, the intensity of the Raman band at 155 cm−1 being strongly enhanced. This band is assigned to the antisymmetric stretching vibration of the I3− ion aligned in the helical poly(viny alcohol) molecule. On the other hand, the intensity of the Raman band at 106 cm−1 is enhanced for Sample A when the 488.0 nm line is used for excitation. This band is assigned to the symmetric stretching vibration of the I3− ion. Its overtones were observed until the sixth. It is clear that the enhancement of the intensities of the 155 and 106 cm−1 bands is closely connected with the absorption bands at 670 and 490 nm respectively.
Photolysis of Nitromethane in Gas Phase at 313 nm
Authors: Honda Koichi , Mikuni Hitoshi , Takahasi Makoto 
Published: July 2006

Abstract
Photolysis of nitromethane in gas phase at 313.0 nm was studied at 55°C. Methyl nitrite, formaldehyde, nitrosomethane and NO were obtained as main products, their quantum yields being determined to be φCH3ONO=0.22, φHCHO=0.20, φCH3NO=0.06 and φNO=0.10. The dependence of the quantum yields on the pressure of quenching gases such as ethylene, cis-2-butene, CO2 and NO were investigated. The quantum yields of products except formaldehyde decrease with increase in pressure of ethylene or cis-2-butene. The sensitized isomerization of 2-butene was also observed. The quantum yield of triplet nitromethane was determined by the Gundall method and compared with that by product analysis. Both give the identical value 0.6. Since φHCHO is not affected by any quencher, it is concluded that formaldehyde is formed directly from singlet excited nitromethane.
A Theoretical Aspect on the Mechanism of Thermal Dimerization of Cyclooctatetraene
Authors: Iwamura Hiizu , Morio Kazuhiko 
Published: July 2006

Abstract
Thermal isomerization of cyclooctatetraene to semibullvalene 6 has been studied theoretically by the MINDO methods. The reaction is predicted to be exothermic by comparison of the calculated heats of formation and to be allowed as a concerted cyclization by constructing a complete MO correlatiom diagram. These findings together with the knowledge of thermal interconversion of cyclooctatetraene and bicyclo[4.2.0]octa-2,4,7-triene 5 suggest a tentative mechanism for thermal dimerization of cyclooctatetraene in which dimers 2, 3, and 4 are formed by coupling of the two isomers 5 and 6 of cyclooctatetraene.
Inositol Derivatives. V. Selective Benzoylation of 1,2-O-Cyclohexylidene-myo-inositol and Preparation of New O-p-Tolylsulfonyl-myo-inositols
Authors: Suami Tetsuo , Ogawa Seiichiro , Ohashi Kumiko , Oki Shuichi 
Published: July 2006

Abstract
The reaction of l,2-O-cyclohexylidene-myo-inositol (1a) with 1.5 equiv. of benzoyl chloride below 0°C gave 3-O-benzoate (2a) predominantly in 40% yield, together with easily separable 3,6-di-O-benzoate (3a) in 2.5% yield. Selective sulfonylation of 2a gave three new O-p-tolylsulfonyl-myo-inositols (the 4,6- (8a), 4,5- (9a), and 4,5,6-p-toluenesulfonates (10)). From 3a, two O-p-tolylsulfonyl derivatives (5- (15a) and 4,5-p-toluenesulfonates (16)) were obtained. The relative reactivities, toward benzoylation, of the hydroxyl groups of 1a were shown to be almost similar to those observed in tosylation. The p-tolylsulfonyloxy function on C–5 of 10 was found to be readily displaced preferentially by chloride ion.
Calculation of Optical Rotational Strength by Means of Various Types of Molecular Orbitals
Authors: Imamura Akira , Hirano Tsuneo , Nagata Chikayoshi , Tsuruta Teiji 
Published: July 2006

Abstract
The optical rotational strengths of the methyl derivatives of cyclohexanone were calculated by means of various types of molecular orbitals, which were converted from those used in the CNDO/2 method. One of them is represented as a Sla ter-basis atomic orbital transformed from molecular orbitals on a CNDO basis by using the overlap matrix. Another was obtained only by modifying the normalization coefficient of the molecular orbitals. From the results, the two-center matrix elements in the calculation of rotational strengths was found to be not negligible, hence, the above-mentioned transformation was indicated to be indispensable. Good agreement with the experimental results was found for the transformed molecular orbitals, especially for those with a modification of the normalization coefficient. The theoretical grounds for these transformations are discussed. The formulae for the matrix elements of the gradient operator which are necessary for the calculation of the rotational strength are given in the appendix.
Studies of Helical Aggregates of Molecules. III. The Bivalent Metal Soaps of Optically Active 12-Hydroxyoctadecanoic Acid
Authors: Tachibana Taro , Kayama Kazuko , Takeno Hideko 
Published: July 2006

Abstract
The bivalent metal soaps of optically-active 12-hydroxyoctadecanoic acid were found to crystallize out in the form of twisted fibers from aqueous or anhydrous ethanol solutions. Most soaps of this class produced both righthanded and left-handed fibers from the same specimen, more of the latter in the case of the D-enantiomer. An enantiomorphic relationship of the sense of twist was clearly demonstrated by using both enantiomers of the Ca soap. Under a high-resolution electron microscope, it was observed on the Sr soap that Sr atoms are arranged in lines along the fiber axis with a periodicity of 33–40 Å, showing that the hydroxyoctadecanoate chains of the soap molecules are aligned approximately parallel to the width of the fiber. The twisting of the soap fibers was associated with the layer structure characteristic of soap.
The Second CMC of the Aqueous Solution of Sodium Dodecyl Sulfate. I. Conductivity
Authors: Miura Masaji , Kodama Michiko 
Published: July 2006

Abstract
The conductivity studies of the aqueous solution of sodium dodecyl sulfate (SDS) over the concentration range of 0–0.12 m revealed that there exists a so-called 2nd critical micelle concentration (CMC) at about 65 mm in addition to the 1st CMC at 8.3 mm. The 2nd CMC was greatly influenced by additives; sodium chloride lowered the 2nd CMC, whereas organic substances, such as dodecyl alcohol and n-hexane, raised it. Moreover, the specific conductivity-concentration curve of the pure SDS solution broke upward at the 2nd CMC, and its slope increased in the presence of sodium chloride, while it bent toward the concentration axis in the presence of a certain amount of dodecyl alcohol or n-hexane. These facts may afford a clue for explaining the micelle structure above the 2nd CMC.
The Synthesis of Purine Nucleosides of l-Mycarose and l-Cladinose
Authors: Koto Shinkiti , Zen Shonosuke , Omura Satoshi , Hata Toju 
Published: July 2006

Abstract
Purine nucleosides of l-mycarose and l-cladinose, neutral branched-chain sugars of macrolide antibiotics, synthesized by a fusion method with the aid of dichloroacetic acid. The structure of these synthesized nucleosides was determined on the basis of the results of elemental analyses and the ultraviolet absorption and proton magnetic resonance spectra, as well as on the basis of the optical rotatory dispersion.
Studies on Stable Free Radicals. VII. The Mechanism for Cyclization Reaction of α-Amino Nitriles with Carbonyl Compounds
Authors: Toda Toshimasa , Morimura Syoji , Murayama Keisuke 
Published: July 2006

Abstract
Substituted 4-oxoimidazolidines were prepared by the condensation of α-amino nitriles with carbonyl compounds, or by the self-condensation of α-amino nitriles. The mechanism of the reaction was studied. The mass spectrum of the condensation product obtained by the reaction of cyclohexanone with 1-amino-1-cyano-15N-cyclohexane (III) or by the self-condensation of III, and the ESR spectrum of corresponding nitroxide radical obtained by the oxidation of the respective condensation products served to elucidate the reaction mechanisms for these condensation reactions. The mechanism for the self-condensation of α-amino nitriles proposed previously was corrected from the spectral data of the reaction product. Possible mechanisms for these condensation reactions are proposed.