bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Separation Scheme for the Analysis of Metal Ions Using Column Extraction Chromatography. Grouping of Nineteen Metal Ions into Six Fractions
Authors: Akaza Ikuko , Tajima Takatoshi , Kiba Toshiyasu 
Published: July 2006

Abstract
A new scheme for the quantitative group separation of 19 common cations by reversed-phase extraction column chromatography has been devised. The following six columns, in which the organic solvent was adsorbed on Daiflone(polytrifluorochloroethylene), were prepared: a TBP–2n HCl column for Fe(III), Hg(II), and Sn(IV); a TOA(CCl4)–2n HCl column for Ag(I), Bi(III), Zn(II), and Cd(II); a TBP–6n HCl column for Sb(III); an AcAc(CHCl3)–pH 5.0 column for Cr(III) and Al(III); a TTA(MIBK)-pH 5.0 column for Cu(II), Co(II), Ni-(II), Pb(II), Mn(II), and Mg(II), and a TTA(MIBK)-pH 7.0 column for Ca(II), Sr(II), and Ba(II). After a test solution had been passed through the six columns successively in the above order, the metal ions are grouped and entirely retained on the specified columns.
Dehydration in Liquid Sulfur Dioxide. I. Acid Amide and Acid Anhydride Synthesis in an Iodine—Pyridine—Sulfur Dioxide System
Authors: Nojima Masatomo , Hasegawa Shigeru , Tokura Niichiro 
Published: July 2006

Abstract
A novel dehydrating reagent consisting of the I2–pyridine–liq. SO2 system has been examined in order to obtain acid amides from carboxylic acids and amines in liq. SO2. Among the amines, aniline gave the most satisfactory results. A fairly good yield was also achieved when the SO2Cl2–Py–SO2 system was used in place of the I2–Py–SO2 system. Various amines in the absence of acids in this system gave N,N′-disubstituted diaminosulfone derivatives in good yields. Benzoic acid itself in the absence of amines gave benzoic acid anhydride in this system slowly.
The Photochemical Reaction of Diphenylacetylene with Enamines
Authors: Miyamoto Norioki , Nozaki Hitosi 
Published: July 2006

Abstract
The irradiation of a mixture of diphenylacetylene (I) and the enamine of the diethyl ketone (II) or of cyclopentanone (IV) gives two β,γ-unsaturated ketones, III and X respectively, in which the diphenylacetylene moiety is formally inserted into the respective enamine double bond under hydrogen migration. The reaction with the enamine of cyclohexanone (V) affords 2-(1,2-diphenylvinyl)cyclohexanone (XIII) as the major product in addition to the cycloadduct (XV). In each case, the formation of photodimers of I has been observed. The reaction is quenched by the addition of pyrene, is sensitized by triphenylene, and is supposed to proceed by way of a triplet path. The different routes of the enamine reactions can be explained by considering the geometry of the intermediate diradicals.
Studies on Aminosugars. XXXIII. Syntheses of 4-Azido-2,3,6-tri- O-benzyl-4-deoxy- and 6-Azido-2,3,4-tri-O-benzyl-6-deoxy-α-d-glucopyranosyl Chloride
Authors: Takagi Yasushi , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
The titled compounds (8 and 13) have been prepared as synthetic intermediates.
Quantitative Estimation of the Fehling Reaction of 1-O-Protected Uronic Acids
Authors: Yoshimura Juji , Hashimoto Jun-ichi , Ando Hiroaki 
Published: July 2006

Abstract
Quantitative estimation of the Fehling reaction of 1-O-protected uronic acid derivatives showed that the reducing power of 1-O-protected hexofuranuronic acid derivatives corresponds to 23–37% of that of d-glucose. The presumption that the reducing ability might be attributed to the formation of unsaturated aldehydo-sugars by removal of the 1-O-protecting group through a cupric ion-catalyzed β-elimination was supported by the fact that 2,5-dimethoxy-6-oxo-2,4-hexadienoic acid was formed by alkaline β-elimination of methyl (methyl 2,3,5-tri- O-methyl-α-d-glucofuranosid)uronate.
The Reaction of Nitriles with Phosgene. VII. Synthesis of α,β-Unsaturated Isocyanates
Authors: Ohoka Masataka , Yanagida Shozo , Sugahara Kenji , Fujita Tetsuo , Okahara Mitsuo , Komori Saburo 
Published: July 2006

Abstract
The reaction of nitriles with phosgene in the presence of hydrogen chloride was carried out for synthesizing α,β-unsaturated isocyanates. 3-Chloropropionitrile, 2,3-dichloropropionitrile, isobutyronirtile, and 2-chloromethylpropionitrile gave the corresponding α-chloro-α,β-unsaturated isocyanates in moderate yields (27–50%). Propionitrile, n-butyronitrile, and 3-phenylpropionitrile gave the corresponding pyrimidines as the major product. 3-Phenylpropionitrile, however, gave the isocyanate as the major product when the amount of benzene as a solvent increased. Reaction pathways to isocyanates and pyrimidines were discussed.
Semiconducting Properties of Ln2CuO4 (Ln=Rare earths)
Authors: Kenjo Tadao , Yajima Seishi 
Published: July 2006

Abstract
The temperature dependence of the resistivity and the thermoelectric power of Ln2CuO4 (Ln=rare earths) have been measured. The compounds of Gd, Sm, Nd, and Pr are semiconductive, while La2CuO4 shows metallic conductivity. The tetragonal lattice of La2CuO4 shrinks in the a axis and expands in the c axis compared to Pr2CuO4, in spite of the steady expansion of these lattice parameters for the compounds between Gd and Pr. The thermoelectric power of Ln2CuO4, but not La2CuO4, is negative, suggesting an electron-conducting or n-type semiconductor. The resistivity of the Ln2CuO4 at room temperature increases essentially with an increase in the atomic number of Ln. The plots of the thermoelectric power vs. the reciprocal temperature showed a steeper slope for the compounds of the heavier rare earths. The semiconductor-metal transition observed between La2CuO4 and Pr2CuO4 was explained in relation to the structural change (the shrinkage of the a axis and the expansion of the c axis) as being due to the change in the electron configurations of Cu2+.
Interpretation of Photoelectron Spectra of Halomethanes
Authors: Katsumata Shunji , Kimura Katsumi 
Published: July 2006

Abstract
Theoretical studies of the electronic structure of chloromethanes (CH4−nCln, where n=1∼4) were carried out by the CNDO/2 method. The resulting Koopmans’ theorem ionization energies were generally in good agreement with the experimental data available, and somewhat different assignments from those previously reported were obtained for the nonbonding orbitals. A “sum rule” was employed for interpreting the photoelectron bands of three series of di- and poly-halomethanes (chloro-, bromo-, and iodo-methanes) in terms of some localized molecular orbitals. Reasonable assignments were derived for the photoelectron spectra of all these halomethanes and the resulting assignments for the chloromethanes were in good accord with those obtained from the CNDO/2 calculation.
Dielectric Studies on Isobutyl Halides in the Liquid State
Authors: Das Arati , Ghatak Alpana , Hasan Abul 
Published: July 2006

Abstract
The activation energies of dielectric relaxation ΔHτ in three isobutyl halides in the liquid state are found to be almost equal to the mean value of the electrostatic self energies of the trans and gauche isomers in the corresponding compounds. The energy difference between the two isomers in the liquid state obtained from the dipole moment measurements agree well with those obtained by the spectroscopic method.
On the MO Perturbation Theory of Molecular Rearrangements
Authors: Fujimoto Hiroshi , Miyagi Morio , Yamabe Shinichi , Fukui Kenichi 
Published: July 2006

Abstract
The relationship between two simple Hückel MO perturbation treatments of electrocyclic reactions formerly proposed has been examined. The reason why the two different approaches give the same prediction with regard to the favorable paths of the reactions has been established numerically. A calculation of the thermal ring-closing of butadiene has been carried out, including both sigma and pi electrons.
An X-Ray Redetermination of the Crystal Structure of Tin(II) Chloride Dihydrate
Authors: Kiriyama Hideko , Kitahama Katsuki , Nakamura Osamu , Kiriyama Ryôiti 
Published: July 2006

Abstract
The crystal structure of tin(II) chloride dihydrate, SnCl2·2H2O has been redetermined by a single crystal X-ray diffractometer technique. The crystal is monoclinic, space group P21⁄c with a=9.313, b=7.250, c=8.970 Å, β=114°55′ and Z=4. The structure was solved by three-dimensional Patterson and electron density syntheses. An anisotropic least-squares refinement, based on 1695 independent reflections gave an R value of 0.04. The tin(II) atom forms a pyramidal complex with two chlorine atoms and one oxygen atom; the bond lengths in the pyramid are Sn–O, 2.33 and Sn–Cl, 2.50 and 2.56 Å and the bond angles are 86.9, 85.0, and 87.9°. These results support a view that the bonding in dichloroaquotin(II) complex is considerably ionic in character. This crystal consists of double layers of the aquocomplex, SnCl2·(OH2), parallel to (100) with intervening layers of the second water molecules. Both kinds of the water molecules are linked together by hydrogen bonds of 2.74, 2.79, and 2.80 Å into two-dimensional networks. The structure reported previously was found to be in error, although its essential feature was quite similar to the present one.
Ion-Solvent Interaction of Tetraalkylammonium Ions in Solvents of High Dielectric Constant. III. Conductance and Walden Product of Some Partially Substituted Alkylammonium Ions in N-Methylacetamide and N-Methylpropionamide at Different Temperatures
Authors: Singh Raj Deo 
Published: July 2006

Abstract
Ion-solvent interaction of some partially substituted alkylammonium ions in N-methylacetamide (NMA) and N-methylpropionamide (NMP) has been investigated from the point of view of electrical conductance and the derived Walden product. From the results, it seems that like tetraalkylammonium (R4N+) ions, Me3NH+ and CeMe3N+ ions are structure breakers in these solvents while Me3PhN+ ion is neither structure breaker nor structure maker.
Transmission of Substituent Effects through Oxygen and Sulfur Atoms. I. 1H Chemical Shifts of Ring-substituted Phenyl Vinyl Ethers and Sulfides
Authors: Fueno Takayuki , Kajimoto Okitsugu , Izawa Kunisuke , Masago Mitsuru 
Published: July 2006

Abstract
The proton chemical shifts of the vinyl group in ring-substituted phenyl vinyl ethers (PVE) and sulfides (PVS) were measured and related to the Hammett σ constants. It was found that the ρ value for the β-trans proton of PVS, −0.448 τ⁄σ, is greater in magnitude than that of PVE, −0.378 τ⁄σ, in contrast to the tendency reported for the methyl hydrogens in anisole and thioanisole. The results can best be explained in terms of the concept of the through-conjugative (pπ-dπ-pπ) behavior of the sulfur atom interposed between two unsaturated groups.
Transmission of Substituent Effects through Oxygen and Sulfur Atoms. II. 13C Chemical Shifts of Ring-Substituted Phenyl Vinyl Ethers and Sulfides
Authors: Kajimoto Okitsugu , Kobayashi Masaru , Fueno Takayuki 
Published: July 2006

Abstract
The 13C chemical shifts of ring-substituted phenyl vinyl ethers and sulfides were measured and discussed in relation to the change in electron distribution caused by the ring-substitution. The Hammett plots of the shifts for the terminal carbon confirm the greater transmission efficiency of sulfur atom. An “inverse” substituent effect was found for the α-carbon of both compounds. This suggests that the bond-polarization plays an important role in the transmission of electronic effect.
Bond Orbital Calculations on the Methane and Silane Molecules
Authors: Kohda Susumu , Katagiri Shigeyoshi 
Published: July 2006

Abstract
The non-empirical calculations of CH4 and SiH4 are carried out by the bond orbital (BO) and McWeeny and Ohno (MBO) methods. The lowest total energies obtained in these calculations are −40.1621 and −290.1809 a.u. for CH4 and SiH4 respectively. The ordinary SC–LCAO–MO calculations are also made for the sake of comparison using the same parameters. The results are compared with the similar calculations of H2O and NH3, we can thus see that the BO and MBO calculations show almost the same features as in H2O and NH3.
Peptide Synthesis via N-Acylated Aziridinone. II. The Reaction of N-Acylated Aziridinone and Its Use in Peptide Synthesis
Authors: Miyoshi Muneji 
Published: July 2006

Abstract
Optically active N-acylated aziridinone, which was synthesized by the dehydration of the corresponding l-acylamino acid, was treated with various nucleophiles, such as alcohol, amine, and water. The ring fission of the aziridinone took place exclusively at the carbonyl-nitrogen bond to give l-acylamino acid derivatives. The reaction was used successfully in the peptide synthesis, using an amino acid ester as a nucleophile. A retention of the optical activity was observed throughout the reaction.
The Reactions of 2-Hydroxybenzophenones with Lead Tetraacetate and Manganic Acetate
Authors: Kurosawa Kazu , Sasaki Yasuko , Ikeda Mikio 
Published: July 2006

Abstract
2-Hydroxy-4-methoxy- and 2-hydroxy-4,4′-dimethoxybenzophenones were oxidized to dimeric compounds with lead tetraacetate and with manganic acetate. 2-Hydroxy-2′,4,4′-trimethoxy- and 2-hydroxy-3′,4,4′trimethoxybenzophenones were oxidized to substituted xanthones. The structures of the products were determined by NMR and mass spectra, and were confirmed by syntheses.
Aminosugars. XXI. Conformation of Cyclic Imido Groups Attached to the Glucopyranose-ring
Authors: Iwakawa Masaharu , Yoshimura Juji 
Published: July 2006

Abstract
Conformation of cyclic imido groups at different positions on O-acetylated-d-glucopyranose-ring was examined from the anisotropic effect of the carbonyls on vicinal ring-protons. The imide-plane at β-C1, C3 were deduced to be slightly inclined counter-clockwise, from the right angle to the mean plane of the pyranose ring, and that at α-C2 and C4 clockwise. 3-Deoxy-1,2 ; 5,6-di-O-isopropylidene-3-phthalimido-α-d-gluco- and -allofuranose were also examined.
Mössbauer Study of the Thermal Decomposition Products of SrFeO4
Authors: Ichida Toshio 
Published: July 2006

Abstract
The thermal decomposition products of SrFeO4 were studied by 57Fe-Mössbauer-effect and X-ray-diffraction measurements. Below 300°C in air, an amorphous Fe3+ product was formed. The Fe4+ or Fe5+ state was not observed in the process. A single-phase product with a perovskite structure was obtained in air at temperatures above 400°C. The products obtained between 400 and 650°C showed cubic symmetry, but above 700°C they showed tetragonal distortion. Two kinds of Fe3+-ion sites were detected in the tetragonal SrFeOx. compounds. All the products obtained under the oxygen pressures from 50 to 500 atm and at temperatures from 300 to 900°C showed cubic symmetry. The Fe3+/Fe4+ ratio in those products was determined from the relative intensities of the Mössbauer absorptions.
Infrared Study of Carbon Dioxide Adsorbed on Magnesium and Calcium Oxides
Authors: Fukuda Yasuo , Tanabe Kozo 
Published: July 2006

Abstract
The infrared absorption spectra of CO2 adsorbed on MgO and GaO were measured in the wide region 700–4000 cm−1 at various amounts of adsorbed CO2 and temperatures of adsorption and desorption. It has been found that both uni- and bidentate carbonates are formed on MgO when a small amount of CO2 is adsorbed and that unidentate carbonates predominate as the amount of adsorbed CO2 is increased. On the other hand, only unidentate species were formed on CaO at room temperature independently of the amount of adsorbed CO2, but bidentate species were also formed on CaO when the temperature of adsorption was high. The unidentate carbonates formed on both MgO and CaO at room temperature partially changed to bidentate carbonates upon evacuation at higher temperatures. The correlation between Δv=|v1–v5| and the partial charge on oxygen atoms of various oxides, which corresponds to basic strength on the surface, was examined.
Studies on Actinoid Elements. V. The Determination of the Np(V)/Np(IV) Ratio in an Aqueous Solution by Means of the Partition Method
Authors: Ohyoshi Akira , Kawamura Tsuneo 
Published: July 2006

Abstract
The distribution study of neptunium ions in an aqueous solution containing Np(IV) and Np(V) was made using the metal chelate extraction system, TTA-benzene, or HDEHP-benzene at room temperature. The results obtained by this method were then compared with those obtained by spectrophotometry. In each system, a linear relationship was obtained between the fraction of the Np(V) ion and 1/(D+1), where D is the distribution ratio of neptunium. This analysis was performed with an accuracy of ±5% and was established within one minute in the case of the HDEHP-benzene system. The results obtained by this method were in good agreement with those obtained by spectrophotometry.
Studies of the Surface of Rutile Single Crystals by Means of Electrical Conductivity
Authors: Iwaki Toru 
Published: July 2006

Abstract
The surface properties of rutile single crystals were studied by the measurement of the d.c. electrical conductivity. Upon successive thermal treatments in vacuo from 25 to 550°C, the electrical conductivity on the (110) plane increased remarkable, while the activation energy decreased. The addition of oxygen decreased the conductivity according to the oxidation temperature, whereas the reduction by hydrogen above 300°C increased the conductivity greatly. The number of carriers was also determined from the measurement of the Hall effect. These results, by reference to those of the photoconductivity, were interpreted in terms of the change in the energy band structure near the surface associated with the defect centers on the surface.
Dielectric Behavior of the Packing Bed of Alumina Granules with Adsorbed Water
Authors: Umeya Kaoru , Kanno Takashi 
Published: July 2006

Abstract
Dielectric behavior of the packing bed of alumina granules with various amounts of adsorbed water were determined in the frequency range 30 Hz–3 MHz. The dielectric relaxations characterized by a distribution in relaxation time were attributed to interfacial polarizations due to the adsorbed ions accumulated around the non-conductive points (i.e., discontinuous points on conducting paths consisting of water films adsorbed on alumina granules). Some of the adsorbed ions were carried away to the electrodes through the points of contact between the water films adsorbed on granules adjacent to each other (i.e., continuous conducting paths), giving rise to d.c. conductance and electrode polarization. When insulating sheets were inserted between the electrodes and surfaces of the packing bed, both the d.c. conductance and electrode polarization disappeared and another dielectric relaxation was observed. This was attributed to the interfacial polarization due to the ions accumulated at the interfaces between insulating sheets and water adsorbed on alumina granules.
Potentiometric Studies of Cadmium- and Zinc-Halide Complexes in Acetonitrile
Authors: Aihara Makoto , Misumi Seizo 
Published: July 2006

Abstract
The overall formation constants of cadmium- and zinc-halide complexes in acetonitrile were determined by potentiometric titration using a saturated metal amalgam indicator electrode. The effect of ion-pair formation was taken into consideration to elucidate the free halide ion concentration in the experiments. The values of logβ3 and logβ4 for cadmium-halide complex were found to be: I−, 22.4 and 26.5; Br−, 25.3 and 29.8; Cl−, 29.2 and 34.0. The values for zinc-chloride complex were 20.1 and 23.4.
Derivatographic Studies on Transition Metal Complexes. IX. Thermal CN-Bridging Reaction of Double Complex Salts in Solid Phase
Authors: Tsuchiya Ryokichi , Nakagawa Shigeo , Uehara Akira , Kyuno Eishin 
Published: July 2006

Abstract
It was found by derivatography and spectral measurements that the double complex salts, [Co(H2O)2N4] [Co(CN)6]·nH2O, where N4 is 4NH3, two moles of ethylenediamine (en) or one mole of triethylenetetramine (trien), [Co(NH3)2trien][Co(CN)6]·2H2O, [Co(NH3)tepa][Co(CN)6].2H2O, where tepa is tetraethylenepent-amine, and [Co(H2O)2trien][Cr(CN)6]·2H2O underwent deaquation-or deammonation-CN-bridging formation reaction upon heating. The general tendency was observed to be as follows: the more stable the structural configuration of the coordination sphere, the higher the activation energy. In the case of the complex containing hexacyanochromate(III) as an anion, the activation energy for the bridging formation reaction is especially high as a result of possible flipping in CN bridging groups.
Determination of Arsenic(III) by Anodic Stripping Method Using Co-deposition with Copper
Authors: Kuwabara Takeshi , Suzuki Shigetaka , Araki Shun 
Published: July 2006

Abstract
The determination of arsenic(III) by anodic stripping using co-deposition with copper was worked out. A 0.24 M hydrochloric acid containing arsenic(III) and copper(II) was electrolyzed with a rotating platinum electrode (rpm=800) at a constant current. The deposit on the electrode was stripped by linear potential sweep method in 4 M hydrochloric acid. The stripping voltammogram was recorded in the span voltage −0.2–+1.2 volt vs. SCE. The stripping voltammogram showed two peaks, at zero volt and 0.5 volt vs. SCE. The area of the second peak was proportional to the concentration of arsenic. Linear dynamic range was 1–20 microgram per milliliter. The method was rapid and simple, the time required for analysis being about 35 minutes (electrolysis temperature, 25°C). X-ray and electron diffractions indicate that the second peak in the stripping voltammogram results from the dissolution of Cu3As.
Methylene Analogs of Cyclobutenedione. VII. Photolysis of 2,3-Bis-(diphenylmethylene)cyclobutanone and Its Derivatives
Authors: Toda Fumio , Nakaoka Hisao , Yuwane Kentaro , Todo Eishiro 
Published: July 2006

Abstract
Photolysis of 2,2-dimethoxy-3,4-bis(diphenylmethylene)cyclobutanone (I), 2,3-bis(diphenylmethylene)cyclobutanone (XIV), and 3,4-bis(diphenylmethylene)cyclobutanedione (XXV) in methanol was investigated. Photolysis of I afforded tricyclic compound(II) and dimethyl cyclobutanedicarboxylate (III) in 48 and 35% yields, respectively. Photolysis of XIV and XXV afforded the dihydronaphthalene derivatives (XIX) (88% yield) and XXIV (72% yield), respectively. The mechanisms of these reactions were also studied.
Mechanism of Oxygen Exchange Reaction of Diaryl and Alkyl Aryl Sulfoxides in Sulfuric Acid
Authors: Kunieda Norio , Oae Shigeru 
Published: July 2006

Abstract
The mechanistic investigations of the concurrent oxygen exchange and racemization reactions of 18O-labeled and optically active methyl p-tolyl sulfoxide (I) and phenyl p-tolyl sulfoxide (II) in sulfuric acid of various concentrations have been carried out by the determination of detailed kinetics. The kinetic data were analyzed in the lights of kex⁄krac values, activation parameters, correlations between the rates and acidity functions, solvent isotope effects, polar effects of substituents, etc.. A gradual change of mechanism of the reaction from an SN2 type process to a predominant A-1 like one (in above 95% sulfuric acid) with the increase of the concentration of sulfuric acid was observed. All these observations suggest that the A-1 like reaction takes place through a cation radical (–\overset+·S–) or a dication (–\overset++S–) intermediate at higher concentrations of sulfuric acid, while the SN2 type reaction that involves a water molecule as nucleophile in the rate-limiting step is the predominant path in less concentrated sulfuric acid.
Polarographic Studies of Some Lanthanoids(III) in N,N-Dimethylacetamide
Authors: Aihara Makoto , Misumi Seizo 
Published: July 2006

Abstract
Polarographic behaviour of some lanthanoids(III) has been studied in N,N-dimethylacetamide. La(III), Pr(III), and Nd(III) showed irreversible, three-electron reduction wave and the other lanthanoids(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), and Lu(III) except Sm(III), Eu(III), and Yb(III), gave irreversible, three-electron reduction wave with a pre-wave. The kinetic parameters for La(III), Pr(III), and Nd(III) were determined by means of Koutecky’s method. Sm(III), Eu(III), and Yb(III) showed two-step reduction waves, the first wave being a reversible, one-electron reduction wave. These solvated lanthanoids(III) were investigated also by cyclic voltammetry.