bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Orbital Treatment of Nitric Oxide Radicals. I. Electronic Structure and Spectrum of the H2NO Radical
Authors: Kikuchi Osamu 
Published: July 2006

Abstract
A theoretical treatment of the H2NO radical is presented. In the calculation, the approximate SCF method of Longuet-Higgins and Pople for open-shell molecules is applied to the valence electron system, the CNDO/2 approximation is adopted, and the molecular excited states are approximated by linear combinations of some doublet Slater determinants constructed by means of the SCF MO for the ground state. The results thus obtained for the electronic structure of the H2NO radical are discussed. The calculated spectrum for the H2NO radical shows that the longest wavelength band has the n→π* character, and the π→π* transition energy is smaller than that for the n→σ* transition. The π→π* transition energy, 5.77 eV, calculated by the method in which only the π-electrons were explicitly considered, indicated that the π→π* band falls into the area near 240 mμ. From the calculated results for the H2NO radical and the solvent effect on the absorption bands of aliphatic nitric oxide radicals, two bands, at 450 mμ, and 240 mμ, characteristic of the latter radicals have been assigned to the n→π* and π→π* transitions respectively.
Intramolecular Hydrogen Bonds. XIV. Correlation of the Hydroxyl and the Carbonyl Frequencies of Methyl Salicylates with Hammett’s Substituent Constants
Authors: Mori Nobuo , Asano Yuzuru , Tsuzuki Yojiro 
Published: July 2006

Abstract
The infrared OH and C=O stretching spectra of methyl 4- or 5-substituted salicylates have been measured in dilute carbon tetrachloride solutions, and the respective peak-frequencies have been correlated with ordinary Hammett’s σ-constants. The best linear relationship has been established between the γOH and the (σOH−0.38σCOOMe) values and between the γC=O and the (σCOOMe−0.49σOH) values, where σOH and σCOOMe are the σ-constants of a substituent with respect to the OH and the COOMe group respectively. Besides, in other internally-bonded phenol systems, including o-bromophenols, o,o′-dihalophenols, and salicylic acids, the plotting of the OH frequencies against the (σOH−AσX) values gave the best linear relationship, where A is a constant depending on the kind of proton acceptor, X. The value of A can be a measure of the electronic effects of the substituent, influencing the bonded OH frequency through X.
Synthesis of 1- and 2-Piperidinophenazine Derivatives
Authors: Endo Hideo , Tada Masao , Katagiri Ken 
Published: July 2006

Abstract
A number of new piperidinophenazines have been prepared by the reactions of various halogenophenazines and their oxides, including several new compounds, with piperidine. The halogenactivating effect of the oxide groups in 1- or 2-halogenophenazine oxides, which had previously been known, was also observed in the present piperidination. It has been found that 1-chlorophenazine was considerably less reactive than 2-chlorophenazine in the piperidination, that but the 5-oxide group in 1-chlorophenazine-5-oxide enhanced the reactivity of chlorine.
The Cooxidation of Hydrocarbons in the Liquid Phase. V. Determination of the Reactivity Ratios
Authors: Niki Etsuo , Kamiya Yoshio , Ohta Nobuto 
Published: July 2006

Abstract
The cooxidations of cumene (C) and tetralin (T) and of styrene (S) and tetralin were studied in the presence of azobisisobutyronitrile; the reactivity ratios, r, were obtained as rC=0.21 and rT=5.0 for the cumene-tetralin system at 80°C and as rS=2.7 and rT=0.49 for the styrene-tetralin system at 70°C. A new method for the determination of r values from the rates of cooxidation has been developed. The merits and demerits of several methods for the determination of r values are discussed. In cases where a large curvature, preferably a rate minimum, is obtained by plotting the rates against the reactant compositions, the determination from the rates of cooxidation may be most suitable. In other cases, the use of the copolymerization equation may be preferable by product analyses. The hydroperoxide method may be valid for some systems.
The Flow Properties of γ-Polyglutamic Acid Solutions in Capillary
Authors: Mineshita Takeshi , Matsumura Shigeru , Ono Hiromi , Watanabe Takehiko , Ono Sôzaburo 
Published: July 2006

Abstract
Dependence of the viscosity of the solution of γ-polyglutamic acid in eater at various pH’s on the bore-size of the capillary viscometer has been studied at 25°C at various concentrations (0.01–0.05 g/100 ml). Measurements were carried out with a Maron-Belner type low shear capillary viscometer with various capillary radii (1.9×10−2–7.6×10−2cm) within the shear stress range 0.2–20 dyn/cm2 at the capillary wall. The polymer solutions showed a non-Newtonian flow behavior and a capillary bore-size dependence and both of these properties were diminished with the decreasing of pH. This capillary bore-size dependence may be attributed to the geometric hindrance of the capillary wall to the thermal motion of the polymer molecules near the wall. The dissolved state of the polymer molecules in solutions of various pH’s has been studied by means of optical rotatory dispersions, flow birefringence and intrinsic viscosity. The dissolved state of the polymer solution as well as the capillary bore-size dependence were sensitive to pH. The polymer molecule in neutral and alkaline media may be in the form of a highly expanded chain and in acid medium in a contracted form having a some ordered chain conformation.
Zeeman Effect of Phosphorescence. II. Intensity Considerations on Pyrazine Phosphorescence
Authors: Azumi Tohru , Ito Mitsuo , Nagakura Saburo 
Published: July 2006

Abstract
The Zeeman splitting of pyrazine phosphorescence is observed. The amount of splitting is 1.4 cm−1 under the magnetic field of 15 kilogauss. This magnitude is just what one expects for the free spin, which means that the zero-field splitting parameters are small compared with the observed splitting. On the assumption of random orientations of the pyrazine molecules in the sample, the phosphorescence intensities from the three split subcomponents are expected to be in the ratio of 13g1 : 16g0 : 13g−1 where g’s represent populations. This expectation is roughly manifested in the experimental observation. Finally, the theoretical calculation of the zero-field splitting parameters, D and E, is attempted, and the results are interpreted in terms of the experimental data.
Studies of Purine N-Oxides. III. The Synthesis of Purine 3-N-Oxides
Authors: Kawashima Hideaki , Kumashiro Izumi 
Published: July 2006

Abstract
6-Methoxy- and 6-ethoxypurine 3-N-oxides were obtained by the direct oxidation of the corresponding 6-alkoxypurines with hydrogen peroxide in aqueous acetic acid. 6-Chloropurine was oxidized with monoperphthalic acid in ether to give 6-chloropurine 3-N-oxide. These purine 3-N-oxides were then converted to hypoxanthine 3-N-oxide by hydrolysis with a sodium hydroxide solution. 6-Methoxypurine 3-N-oxide and hypoxanthine 3-N-oxide were identified with authentic samples unambiguously synthesized from 6-methylsulfonylpurine 3-N-oxide, which had itself been obtained by the oxidation of 6-methylthiopurine 3-N-oxide. The treatment of hypoxanthine 3-N-oxide with hydrochloric acid gave 6,8-dihydroxypurine, 8-chlorohypoxanthine, hypoxanthine, and 2-chloro-4-amino-5-imidazolecarboxamide.
Polymerization of Naphthalene and Reactions of Polynaphthalene
Authors: Minato Hiroshi , Higosaki Nobuyuki , Isobe Chieko 
Published: July 2006

Abstract
Naphthalene was polymerized by use of anhydrous aluminum chloride. The polynaphthalene formed was soluble in various organic solvents. The molecular weight determination suggested that the average degree of polymerization was six. The NMR spectrum indicated the presence of non-aromatic hydrogens, and the elemental analysis roughly corresponded with (C10H8)n. The reactions of the polymer was examined such as hydrogenation, bromination, thermal dehydrogenation, chloromethylation and epoxidation.
The Wolff Rearrangement. V. Kinetic Isotope Effect of α-Diazoacetophenone
Authors: Yukawa Yasuhide , Ibata Toshikazu 
Published: July 2006

Abstract
Kinetic isotope effect of the Wolff rearrangement of carbonyl-14C and phenyl-1-14C labeled α-diazoacetophenone was measured in t-butyl alcohol at 30°C, using a solution of silver benzoate in triethylamine as a catalyst. No apparent kinetic isotope effect was observed in both cases within experimental error. These results suggest that the elimination of nitrogen and the migration of phenyl group proceed in two steps in the rate-determining step.
Thermodynamic Properties of Neopentane from 4°K to the Melting Point and Comparison with Spectroscopic Data
Authors: Enokido Hisae , Shinoda Takako , Mashiko Yo-ichiro 
Published: July 2006

Abstract
Heat capacities, latent heats and vapor pressures of solid and liquid neopentane were measured and the following values were obtained; heat of transition=628.7±0.3 cal/mol, T(trans. pt.)=140.498±0.05°K, heat of fusion=740.0±0.3 cal/mol, T(triple pt.)=256.750°K, and P(triple pt.)=268.47±0.13 Torr. The amount of impurity in the sample after purification was estimated from a plot of the equilibrium temperature against the reciprocal of the fraction melted. From the result the impurity present was found to be 0.0032 mol%. Despite of high purity, Cp value in the region below the melting point increases unexpectedly with temperature. This is interpreted as an effect of formation of vacancies in the crystals. The enthalpy required to form vacancies was estimated to be 3240±220 cal/mol from the analysis of the heat capacity curve in the region below the melting point. The molal entropy of the ideal gas at the boiling point, calculated from the calorimetric data, was 71.24±0.3 e. u. To bring this value into agreement with the value calculated from the infrared and Raman frequencies and the moments of inertia, requires the assumption of three equal potential energy maxima of 4.4 kcal/mol for hindered internal rotation of the methyl groups.
Effect of Potassium Promoter on Iron Oxide Catalysts for Dehydrogenation of Ethylbenzene to Styrene
Authors: Shibata Katsue , Kiyoura Tadamitsu 
Published: July 2006

Abstract
The catalytic activity and the sintering property of iron oxide catalysts with and without potassium additives have been studied. The potassium oxide acts as a promoter and is effective under given conditions in increasing the activity of the catalyst from four to ten times. The effects of the promoter can be classified thus: (1) Structural promoter: The increase in the apparent bulk density and the shrinkage of the catalyst tablet upon calcination during the preparation of the catalyst are prevented by potassium additives. The differences in the specific surface area and in the pore volume of the catalyst between with and without potassium promoter are slight. These effects on iron oxide appear to be caused largely by the formation of K2Fe22O34. (2) Synergetic promoter: The potassium promoter changes the apparent energy of activation of the dehydrogenation reaction from 28 to 43 kcal/mol. The increase in the catalytic activity is due to the increase in the pre-exponential factor. The increase in the factor can be explained in terms of the higher concentration of the active center produced by the interaction of the potassium promoter with iron oxide. (3) Selectivity promoter: The formation of benzene by a side reaction is retarded by potassium additives.
The Crystal and Molecular Structure of Bis-(N,N′-π-cyclopentadienyl cobalt)-di-tert-butyl Urea, (π-C5H5Co)2(N,t-C4H9)2CO
Authors: Matsuura Yoshiki , Yasuoka Noritake , Ueki Tatzuo , Kasai Nobutami , Kakudo Masao 
Published: July 2006

Abstract
The crystals of (π-C5H5Co)2(N-t-C4H9)2CO are orthorhombic, and the space group is Fdd2, with a=9.101, b=17.973, c=23.616 Å, and Z=8. The crystal structure was determined with use of MoKα counter data, the final R being 0.063 for 578 non-zero reflections. The molecules has a C2 symmetry, and the carbonyl group lies exactly on the two-fold axis. Unexpectedly, the molecule has the local structure of N,N′-di-t-huty urea, two nitrogen atoms being bridged to two cobalt atoms. The two crystallographically independent Co-N bonds are 1.942 and 1.951 Å, which are equal within the limits of experimental error. Two cobalt atoms are directly bonded to each other at a distance of 2.371 Å, which is shorter than that of 2.47 Å found in (CO)6Co2(C2Ph2).
The Crystal Structure of Two Crystalline Polymorphs of N-(p-Methoxy phenyl-3-propyl)-p-bromobenzamide
Authors: Yasuoka Noritake , Kasai Nobutami , Kakudo Masao 
Published: July 2006

Abstract
The crystal structure analysis of N-(p-methoxyphenyl-3-propyl)-p-bromobenzamide was carried out by means of X-rays. This compound crystallizes in two crystalline polymorphs, both belonging to the monoclinic system.
α-form:a=14.592,b=9.572,c=11.242Å,β=94.26°;Z=4;space groupP21c
β-form:a=11.940,b=10.019,c=6.577Å,β=90.56°;Z=2;space groupP21.
A little difference in structure is observed between the molecules in the two polymorphs, while the conformations of the carbon-carbon bonds in the 3-aminopropyl group are of the trans form. In both forms, belts of molecules parallel to the b axis are formed by hydrogen bonds between the amide groups of the molecules related by the twofold screw axis. These belts are packed anti-parallel in the α-form, but parallel in the β-form.
The Electronic Structures of Unstable Intermediates. Benzyne and Hetarynes
Authors: Yonezawa Teijiro , Konishi Hideyuki , Kato Hiroshi 
Published: July 2006

Abstract
A semi-empirical SCF MO method for valence electron systems, a modification of our previous method made by introducing the zero-differential overlap approximation except for the one-center exchange integrals, is presented. The results calculated for benzene, pyridine, pyrimidine and thiophene, the parent molecules of benzyne and hetarynes, using this modified method are compared with those obtained by the other calculations and experiments. The unstable intermediates treated in the present paper are benzyne, pyridynes, pyrimidyne and thiophynes. The unknown bond lengths of benzyne and hetarynes are estimated by a semi-empirical relation given in the present treatment. The nature of the carbon-carbon triplet bonds of benzyne and hetarynes is studied on the basis of the bond lengths and the total π bond orders for these bonds. The charge distributions and excitation energies of benzyne and hetarynes, and the chemical reactivity of some hetarynes are also discussed. The lowest triplet states of these intermediates are shown to be close to the singlet ground states.
The Yields of Photonuclear Reactions Leading to the Production of Beryllium-7 with Bremsstrahlung up to 60 MeV
Authors: Oka Yoshinaga , Kato Toyoaki , Yamadera Akira 
Published: July 2006

Abstract
Beryllium, boron, carbon, oxygen, and fluorine targets with natural isotopic compositions were irradiated by bremsstrahlung with four maximum energies, 30, 45, 55 and 60 MeV, and the yields of 7Be from each of these targets were determined by means of chemical separation and gamma-ray spectrometric measurements. The yields were obtained relative to the yield of the 12C(γ, n)11C reaction at each bremsstrahlung energy. The possible reaction pathways leading to the production of 7Be were discussed. The exponential decrease in the yield value against the difference in mass between the target and the product nuclei was observed.
Cobalt(IV) Ammine Complexes with 5-Nitrosalicylato or Similar Ligands. II. Preparation and Properties of Derivatives
Authors: Yamamoto Yoshihisa , Mori Masayasu , Yoneda Hayami , Misumi Soichi , Ito Kazuo 
Published: July 2006

Abstract
Cobalt(IV) compounds of the formulae: (Remark: Graphics omitted.) have been obtained by procedures analogous to that reported for cobalt(IV) ammine complexes with 5-nitrosalicylato ligands.
The Solvent Extraction of Metal Ions from Sulfuric Acid Solutions with a Mixed Extractant—Long-chain Primary Amine and Di-2-ethylhexylphosphoric Acid
Authors: Watanabe Hiroto 
Published: July 2006

Abstract
The distribution of metal ions between phases of dilute sulfuric acid and carbon tetrachloride containing long-chain primary amine (Primene JM) and di-2-ethylhexylphosphoric acid (D2EHPA) has been investigated. The degree of the extraction of bi- and tervalent metal ions, such as zinc, iron (III), indium, lanthanum, and cerium(III), is found to be the lowest when the organic phase contains 5 g/l of Primene JM and 7–8 g/l of D2EHPA, while a minimum extraction of thorium occurs at a different composition of the organic phase. Thus, thorium can be quantitatively separated from most other metals by extraction from a 0.1n sulfuric acid medium with carbon tetrachloride containing 5 g/l of Primene JM and 7–8 g/l of D2EHPA. Under these extraction conditions, a single extraction is sufficient for the quantitative separation of thorium from high concentrations of lanthanide metals. Contrary to the usual method of extraction using long-chain amines, which involves a tedious multiple extraction, the mixed-extractant technique described is simple and will find many uses in the determinations of thorium in a variety of samples.
Solvent Effects on the g Factors of Semiquinones
Authors: Yonezawa Teijiro , Kawamura Takashi , Ushio Masaru , Nakao Yukimichi 
Published: July 2006

Abstract
The dependence of the g factors of p-benzosemiquinone and its tetrahalogenated derivatives on the solvent composition has been studied in the dimethyl sulfoxide-water system. When the water content of the solvent increases, the g factor of p-benzosemiquinone decreases, that of tetrachloro-p-benzosemiquinone scarcely changes, and the g factors of tetrabromo- and tetraiodo-p-benzosemiquinones increase. These phenomena are interpreted qualitatively by assuming that the water molecule solvates to the carbonyl oxygen atom of semiquinones and by using Stoned equation for the g factor of the polyatomic radical. The dependence of the g factor of p-benzosemiquinone on the solvent composition is quantitatively studied by means of the theory of solvent effects proposed by Gendell, Freed and Fraenkel and by using the 2-site model of Stone and Maki and also the 4-site model. The former model assumes that one carbonyl oxygen atom has one site occupied by a solvent molecule, thus resulting in a dominant g shift. In the later model, two solvent molecules interact with one carbonyl oxygen atom. Both models predict the same relation between the g shift and the solvent composition; this experiment cannot confirm which model is more adequate, although the deduced values of the equilibrium constants indicate that the 4-site model is preferable.
Verification of the Conduction Method in Calorimetry
Authors: Tanaka Satohiro , Amaya Kazuo 
Published: July 2006

Abstract
An ideal three-dimensional model of a conduction calorimeter is presented. In the model, the heat transfer takes place only by conduction. The proportionality relation between the quantity of heat and the area enclosed by the recorded temperature curve and the time axis is proved under several sets of ideal conditions under which the proportionality relation is valid are examined, and thermal compensation is recommended for more precise measurements of heat and for convenience in obtaining thermogenesis curves.
The Crystal and Molecular Structure of Bis(2-hydroxyethylimino-salicylaldehydato)copper(II)
Authors: Iijima Kinya , Oonishi Isao , Muto Fumio , Nakahara Akitsugu , Komiyama Yoshimichi 
Published: July 2006

Abstract
The crystal structure of bis(2-hydroxyethyliminosalicylaldehydato)copper(II) has been determined by means of an X-ray diffraction study of a single-crystal specimen. Four formula units are contained in the monoclinic unit cell, the P21⁄c space group, with lattice parameters of: a=18.41 A, b=4.82 Å, c=19.86 Å, and β=99.1° (Dm=1.50 g·cm−3; Dx=1.50 g·cm−3). The structure has been refined, by means of three-dimensional difference syntheses and the least-squares method, to R=0.095. It has been confirmed that copper(II) links to the 2-hydroxyethyliminopyruvate anion through the phenolic oxygen and the nitrogen of the Schiff base linkage, while the alcoholic oxygen in the ethanol-amine moiety is free from coordination. The two Schiff-base ligands are coordinated around copper(II) in the trans-configuration. All the bond distances and angles in the complex are within the range of normal values. The N-Cu-O angles (91.3 and 91.8°) in the chelate rings are close to a right angle, showing that there is less strain in the chelate structure than in the case of a similar chelate of the pyruvate Schiff base (84.6°).
Mössbauer Studies of the Thermal Decomposition of Iron(II) Pyridine and Picoline Complexes
Authors: Tominaga Takeshi , Takeda Masuo , Morimoto Takeshi , Saito Nobufusa 
Published: July 2006

Abstract
The thermal decomposition of tetrakispyridineiron(II) chloride, tetrakis(γ-picoline)iron(II) chloride, and tetrakispyridineiron(II) isothiocyanate has been studied in nitrogen. These complexes presumably decompose in the following sequences:
Fe(py)4Cl2 → Fe(py)2Cl2 → Fe(py)Cl2 → Fe(py)2⁄3Cl2 → FeCl2,
Fe(γ-pic)4Cl2 → Fe(γ-pic)Cl2 → FeCl2 and Fe(py)4(NCS)2 → Fe(py)2(NCS)2 → Fe(NCS)2.
The Mössbauer spectra of these complexes and of their decomposition products have been studied in terms of the structural change about the iron atom during the thermal decomposition process.
Reaction of Olefin-Palladium(II) Chloride Complexes with n-Butylamine
Authors: Hirai Hidefumi , Sawai Hiroaki , Makishima Shoji 
Published: July 2006

Abstract
Olefin-palladium(II) chloride complexes reacted with n-butylamine to form Schiff’s bases. N-Ethylidene-n-butylamine was obtained by the reaction of the ethylene complex with n-butylamine, accompanied by reduction of palladium(II) to the metal. A tris(n-butylamine)palladium chloride complex was formed simultaneously by ligand substitution reaction. The yield of N-ethylidene n-butylamine was 15–19mol% (calcd on palladium) in 2.5 hr at 25°C, and decreased at temperatures higher than 60 °C with increasing reduction of palladium(II), owing to conversion of N-ethylidene-n-butylamine into either N-crotylidene-n-butylamine or a tarry polymeric substance by aldol type condensation reaction. The n-butylamine-palladium(II) chloride complex did not react with ethylene at 25°C, but reacted with ethylene at 150°C to form a large amount of tarry polymer and a small amounts of N-ethylidene-n-butylamine and N-crotylidene-n-butylamine. The propylene complex and the cyclohexene complex reacted with n-butylamine to yield both 2- and 1-N-propylidene n-butylamine, and N-cyclohexylidene-n-butylamine respectively. The yield of Schiff’s bases from olefin complex decreased in the order, ethylene&gt;propylene&gt;&gt;cyclohexene.
Scrambling of Oxygen in the Diester Produced from Labeled Diacyl Peroxide-Olefin Reaction
Authors: Kobayashi Michio , Minato Hiroshi , Ogi Yoshikuni 
Published: July 2006

Abstract
dl-Dihydroanisoin bis-m-bromobenzoate produced from the reaction between p,p′-dimethoxy-trans-stilbene and m,m′-dibromobenzoyl peroxide labeled with oxygen-18 at the carbonyl oxygen was found to possess completely equilibrated oxygens, and this finding indicated that a four-centerd mechanism was unlikely.
The Reaction of Sulfenyl Chlorides with Thioethers. I. The Scope of the Reactions
Authors: Oki Michinori , Kobayashi Keiji 
Published: July 2006

Abstract
It was found that thioethers reacted with sulfenyl chlorides to give four kinds of products. When the alkyl part of the thioether is capable of producing a rather stable carbonium ion, the thioether gives the chloride and an olefin, which are derived from the cation, the latter reacting also with the sulfenyl chloride to give adducts. There is another path to afford alkyl chloride; that is, an SN2-type reaction takes place when the alkyl part gives a less stable carbonium ion. The third and fourth products are α-chloro sulfide and α,β-unsaturated sulfide, which are seemingly produced via a common intermediate. The latter may react further with the sulfenyl chloride to give enedithiol derivatives.