bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the ESR Spectra of Semiquinone Anions of Xanthene Dyes. Variation in the Linewidth of the Phloxine Semiquinone Anion with the Temperature and the Viscosity in Protic Solvents
Authors: Kimura Kazuie , Imamura Masashi 
Published: July 2006

Abstract
The ESR linewidths of semiquinone anions of xanthene dyes in alkaline protic solvents were studied as functions of the temperature and the viscosity. It was found that the linewidths of phloxine semiquinone, the ESR spectra of which show three hyperfine lines due to two equivalent protons, decrease with a decrease in the temperature or an increase in the viscosity of the solvents, and vary unimolecularly. Such a variation can not be explained either by a usual “chemical exchange” process between different states or by intramolecular motion. We propose that the linewidths may be due to the modulation of the hyperfine coupling constants of H atoms; the modulation results from the dissociation and/or distortion of the hydrogen bonds.
A Polarographic Study of the Zinc(II)Ethylenediamine-N,N′diacetate (EDDA) and –Triethylenetetraamine (Trien) Complexes
Authors: Kodama Mutsuo 
Published: July 2006

Abstract
Zinc(II)–EDDA and –Trien complexes produced kinetic waves. By conducting a systematic examination of the nature of the kinetic waves, the reaction mechanisms and the rates of the rate-determining step were determined. The kinetic wave of the zinc(II)–EDDA complex could be ascribed to the reduction of the zinc(II) aquo ion formed upon its slow dissociation at the electrode surface. From a comparison of the observed rate constant with that estimated on the basis of the proposed reaction intermediate, the dissociation of the zinc(II)–EDDA complex was found to proceed through a reaction intermediate in which the leaving EDDA anion is bonded to the zinc(II) ion through the ethylenediamine chelate ring. In the case of the Trien complex, the kinetic wave could be ascirbed to the reduction of the zinc(II)–Trien complex formed upon the slow configurational change of the tetrahedral zinc(II)–Trien complex at the electrode surface.
The Relative cis/trans Reactivity in the Hydrochlorination of 1-Arylpropenes
Authors: Izawa Kunisuke , Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
Hydrochlorination of cis- and trans-1 -phenylpropenes and their ring-substituted derivatives (p-CH3O, p-CH3, and p-Cl) has been studied in acetic acid at 16–35°C. 1-Phenylpropene gave predominantly a cis-adduct while the p-CH3O derivative yielded a non-stereospecific product. For the p-CH3O and p-CH3 derivatives, the cis isomer was found to be more reactive than the corresponding trans isomer, while for the p-Cl derivative the opposite relative reactivity was observed. The origins of these cis/trans reactivities have been discussed in terms of the electronic and steric effects on stability of the solvated transition state.
The Addition of 2,4-Dinitrobenzenesulfenyl Chloride to cis- and trans-1-Arylpropenes and Some Other Olefins
Authors: Izawa Kunisuke , Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
Kinetic investigations were carried out on the addition of 2,4-dinitrobenzenesulfenyl chloride to the geometrically isomeric pairs of various 1-arylpropenes as well as some related olefins. All the trans isomers of 1-arylpropenes were more reactive than the corresponding cis isomers and the Hammett correlations were observed for respective isomers with ρ=−2.64 (trans) and −2.3 (cis). By contrast, cis-alkenes were more than 10 times as reactive as the corresponding trans isomers. The reactivities of various unsaturated compounds in this reaction were found to be correlated with their ionization potentials constituting two lines accodring to the type of substrates. It was concluded that the greater reactivity of trans-1-arylpropene as compared with the cis isomer is ascribable to the difference in the charge-transfer interaction between the electrophile and a substrate at the transition state. The conclusion is contrasting to the generalization that the relative cis/trans reactivity of alkenes is determined mainly by the Coulombic interaction at the transition state.
Formation and Conformation of Benzoyloxylated Sulfur-containing Heterocycles
Authors: Sugawara Tadashi , Iwamura Hiizu , Oki Michinori 
Published: July 2006

Abstract
Thiane, 1,3-dithiane, and 1,3,5-trithiane were treated with t-butyl peroxybenzoate in the presence of cuprous chloride to yield benzoyloxylated products. Methylenes placed between two sulfur atoms were found to be more reactive than those next to one sulfur atom. Introduction of two benzoyloxy groups into 1,3,5-trithiane afforded cis-2,4-dibenzoyloxy-1,3,5-trithiane only. PMR spectra of benzoyloxylated products at various temperatures indicate that benzoyloxy-axial conformation is overwhelming for all the compounds investigated.
Spin Trapping of Free Radicals Generated from Arylazo p-Tolyl Sulfones
Authors: Kobayashi Michio , Akiyama Eri , Minato Hiroshi , Kito Noboru 
Published: July 2006

Abstract
Arylazo p-tolyl sulfones(I) were thermolyzed or photolyzed in the presence of trapping agents such as α,N-diphenyl nitrone(II), α-phenyl N-t-butyl nitrone(III) and 2-methyl-2-nitrosopropane(X). ESR studies showed that phenyl radical or p-methoxy phenyl radical is produced from the decomposition of I and adds to II or III. The adduct of phenyl radical to II and that of p-methoxyphenyl radiacl to III were synthesized for comparison by separate pathways. The photolysis of phenyl p-tolylazo sulfone(Ia) in the presence of III yielded benzhydryl t-butyl nitroxide, benzoyl t-butyl nitroxide and t-butyl p-toluenesulfonyl nitroxide(XVI) radicals. The photolysis of la in the presence of X gave di-t-butyl nitroxide(XII) and XVI. The photolysis of phenylazotriphenylmethane in the presence of X yielded XII and t-butyl nitroxide radical. The mechanisms of the formation of these radicals are discussed. The formation of arenesulfonyl radicals from the decomposition of I has been proved indirectly (analyses of the products of the combination of nitroxide radicals with arenesulfonyl radicals) and directly (detection of t-butyl p-toluenesulfonyl nitroxide radical.
The Reaction of the Hydroxamic Acid Group in Polymer with p-Nitrophenyl Acetate
Authors: Kunitake Toyoki , Okahata Yoshio , Ando Reiko 
Published: July 2006

Abstract
Water-soluble copolymers containing protected hydroxamate groups were prepared by radical copolymerization of acetyl N-phenylacrylohydroxamate and acrylamide, and the hydroxamic acid group (PHA) was unmasked by treating it with hydroxylamine. In acetylation with p-nitrophenyl acetate (1.4 v/v% CH3CN–H2O, 30 °C) the PHA unit was less reactive than the corresponding monomeric compound. When the PHA content was low (3 mol%), the reactivity of a given PHA anion (true reacting species) was invariant (9.1 M−1 S−1) over a wide range of the dissociation of the PHA unit. However, in the case of the copolymer of a higher PHA content (11 mol%) the reactivity decreased as the neutralization of the PHA anion progressed. This phenomenon was attributed to the intramolecular aggregation of the undissociated PHA side chain. The deacylation rate of the acetylated PHA unit was comparable to those of the monomeric counterparts, in contrast with the acylation process. Finally, the probable role of the PHA unit as catalyst for the ester hydrolysis was discussed.
Studies of Unusual Amino Acids and Their Peptides. V. The Synthesis and the Absolute Configuration of β(2-Thiazolyl)-β-alanine Present in Bottromycin
Authors: Seto Yasuhiko , Torii Kazuhira , Bori K\={o}ichi , Inabata Kenichiro , Kuwata Shigeru , Watanabe Hiroshi 
Published: July 2006

Abstract
In order to obtain an optically-active β-(2-thiazolyl)-β-alanine, N-acyl-l-aspartic α-thionamide-β-methyl ester was condensed with diethyl bromoacetal, but the amino acid thus obtained showed no perceptible optical activity. The racemic amino acid, however, could be resolved into its antipodes by treating its phthalyl derivative with brucine. Thus, the (+)-amino acid, a constituent of bottromycin, was isolated in a pure state; it was determined to belong to the l-series by examining its optical behavior. This amino acid was proved to racemize easily under the conditions of the acid hydrolysis of bottromycin.
Fractionation of Polyvinyl Chloride Pitch by Vacuum Sublimation
Authors: Kamo Mutsukazu , Kanda Hisao , Sato Yoichiro , Setaka Nobuo 
Published: July 2006

Abstract
Pitch prepared by heating polyvinyl chloride at 400 °C (PVC pitch) was fractionated by vacuum sublimation. The fractions were studied by means of elementary analysis, determination of molecular weight, IR spectroscopy and NMR spectroscopy. It was found that each fraction has a characteristic constituent as follows: 1) Zones 1 and 2 are composed of some aromatic nuclei with 3–4 rings and 3–5 rings linked with aliphatic chains, respectively; 2) Zones 3 and 4 are composed of condensed aromatic nuclei with 6–8 rings and 6–7 rings, respectively; 3) In zone 5, aromatic nuclei have 2–4 aromatic rings on an average, and the ratio of the aliphatic group is higher than that of other zones; 4) The sublimation residue is mainly composed of condensed aromatic nuclei, and the ratio of aromatic hydrogen to aliphatic hydrogen in the residue is the highest.
The Alkylation of Phenol over the ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi , Shimokawa Katsuyoshi 
Published: July 2006

Abstract
The highly selective alkylation at the ortho position of phenol was caused by the dissociative adsorption of phenol; it was discussed by taking account of the acidic and the basic properties of the ZnO–Fe2O3 catalyst.
Energized Vinyl Radical Formation in the Photolysis of Ethylene
Authors: Hara Hiroshi , Tanaka Ikuzo 
Published: July 2006

Abstract
Energized vinyl radical formation was found in the primary process of the 1634 Å photolysis of ethylene in the pressure region up to about 1 atm. The energized vinyl radical either decomposes unimolecularly to give acetylene and a hydrogen atom, or is deactivated to a stable vinyl radical at collision.
The Reactions of Several Carbonyl Compounds with Hexamethylphosphoric Triamide
Authors: Arimatsu Seiji , Yamaguchi Ryohei , Kawanisi Mituyosi 
Published: July 2006

Abstract
Non-enolizable carbonyl compounds were found to undergo intriguing reaction upon heating with hexamethylphosphoric triamide; benzophenone gave 1,1,2,2-tetraphenylethane and benzophenone methylimine, while fluorenone afforded 9-methylfluorene, 9-dimethylaminofluorene, and fluorene. In contrast, anthrone, an enolizable compound, was completely recovered unchanged under the the same reaction conditions.
A Study of the Upper and Lower Bounds of the Second-order Perturbation Energy
Authors: Yamabe Tokio , Tanaka Kazuyoshi , Ishimaru Shingo , Fukui Kenichi 
Published: July 2006

Abstract
A method of calculation for the upper and lower bounds of the second-order perturbation energy is investigated. The expression for the upper bound is based on Hylleraas’s variation perturbation condition and is an improved version of that obtained by Goodisman. The lower bound is based on the Temple-type inequality and is an improved version of that by Prager and Hirschfelder. The result is numerically tested for examples of the polarizability of a hydrogen atom and the coefficients (C5 and C8) of the dispersion force between two separated hydrogen atoms, yielding fairly good results. Particularly, the results of the upper bound for C8 are the best so far calculated in a non-empirical way.
Asymmetric Synthesis with Sugar Derivatives. V. The Synthesis of α-Hydroxy Acids on Insoluble Polymer Supports
Authors: Kawana Masajiro , Emoto Sakae 
Published: July 2006

Abstract
The styrene-2% divinylbenzene copolymer containing 1,2-O-cyclohexylidene-5-O-trityl-α-d- or -l-xylofuranose (d- or l-3a) was prepared. Asymmetric Grignard additions to benzoylformate (3b) and pyruvate (3c) were carried out using these polymers as chiral ester-components. Enantiomers of α-hydroxy acids, such as atrolactic acid (4) and 2-hydroxy-2-phenyl-2-(p-tolyl)acetic acid (5), were obtained in relatively good synthetic and optical yields, depending on the use of either d- or l-3a. The optical yields of 4 for the polymer were higher than those for a low-molecular-weight compound, 1,2-O-cyclohexylidene-5-O-trityl-α-d-xylofuranose (8a). It was shown that the polymer could be used repeatedly.
Kinetics of the Autoxidation of Substituted Anthranols to Anthraquinones in Buffered Aqueous Dioxane
Authors: Ogata Yoshiro , Nate Kazuo , Yamashita Mitsuji 
Published: July 2006

Abstract
Autoxidation of 2-substituted anthranols to the corresponding anthraquinones in alkaline buffered aqueous dioxane (2:1 in vol) has been studied kinetically at 35 °C by means of the manometric method. The relative rate constants for the autoxidation of anthranyl oxide ions have been evaluated, in which dissociation of anthrones is taken into account. Application of substituent effect on the one-electron transfer to the oxide ion to the Hammett equation gives an average ρ-value of −1.5, which was little influenced by pH of the solution.
A Base-induced Elimination Reaction of Phenylsulfonylacetates. II. Effects of the Base and the Solvent on the Stereochemistry of Elimination
Authors: Mano Hiroshi , Sera Akira , Maruyama Kazuhiro 
Published: July 2006

Abstract
The base-induced elimination reaction of 1,2-diphenylethyl phenylsulfonylacetate was investigated in a variety of base–solvent systems. A stronger base was found to facilitate syn elimination. The addition of crown ether caused a remarkable change in the stereochemistry of elimination from syn to anti. In aprotic solvents, an overwhelming syn elimination was observed.
The Configuration at C–21 of Hydroxyhopanone
Authors: Sekiguchi Kazuo , Kanemoto Hiroaki , Hirao Yoji , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Hydroxyhopanone (1) was converted via two alternative routes (1→9→11a→12→14→15→16 and 1→10→17→18→19→20) to A-neohop-21-ene (16) and A-neohop-3-ene (20), respectively. These unsaturated hydrocarbons (16 and 20) were found to be identical; this provided evidence to confirm the 21β-H configuration for 1.
Studies on Benzoquinolines(f) and (h). Part II
Authors: Tyagi Rameshwar P , Joshi Bhuwan C 
Published: July 2006

Abstract
3-Hydrazino-1-methyl, 1-hydrazino-3-methylbenzo(f) quinoline (IA, IIA) and 2-hydrazino-4-methyl, 4-hydrazino-2-methylbenzo(h) quinoline (IIIA, IVA) were reported to give triazines and diazepines with nitrous and formic acids. It would be interesting to study the reactions of IA–IVA with acetylacetone and ethyl acetoacetate respectively.
Mechanism of the Oxygen Exchange Reaction of n-Butyl Methyl Sulfoxide in Sulfuric Acid
Authors: Oae Shigeru , Moriyama Masaru , Numata Tatsuo , Kunieda Norio 
Published: July 2006

Abstract
Mechanistic investigations of the concurrent oxygen exchange and racemization reactions of 18O-labeled and optically active n-butyl methyl sulfoxide in sulfuric acid of various concentrations have been carried out. The kinetic data were analyzed in the light of kex/krac values, activation parameters, correlations between the rates and acidity functions, etc. The results seem to suggest that the reaction proceeds through an A-1-like route to afford a cation radical (–\overset+·S–) or a dication (–\overset++S–) intermediate, followed by a fast nucleophilic attack of water to give the starting sulfoxide.
A Novel Rearrangement of Styryl Sulfoxide Induced by Phosphorus Pentachloride
Authors: Miyamoto Norioki , Fukuoka Daisuke , Utimoto Kiitiro , Nozaki Hitosi 
Published: July 2006

Abstract
The reaction of both isomers of methyl styryl sulfoxide (Ia) with the title chloride affords methyl phenacyl sulfide (IIa) and phenyl(α-methylthio)acetaldehyde (IIIa) besides β-chlorostyryl methyl sulfide (IVa). Phenyl styryl sulfoxide reacts similarly.
The Thermal Decomposition and Reduction of Silver(I) Oxide
Authors: Nakamori Issei , Nakamura Hidetsugu , Hayano Toshiyuki , Kagawa Shuichi 
Published: July 2006

Abstract
The thermal decomposition of silver(I) oxide and its reduction with reductive gases, such as ethylene, hydrogen, and carbon monoxide, have been studied by using a fixed-bed flow reactor. Under isothermal conditions, each reaction gave a sigmoidal shape to the fractional decomposition vs. time curves, and these curves were in good agreement with Avrami’s equation. The temperature at which the reaction commenced corresponded well to the chemical affinity of the reaction, and a linear free-energy relationship holds between the apparent activation energy and the standard enthalpy change of the reaction. In the thermal decomposition, an enlargement in particle size resulting from the melting and sintering of the product silver was recognized, but in the reduction the particle size scarcely varied during the reaction. On the basis of these results, the mechanism of each reaction was discussed.
An Infrared Study of the Steric Effects of Alkyl Substituents on the N–H Stretching Absorptions of sym-Dialkylureas
Authors: Mido Yoshiyuki 
Published: July 2006

Abstract
By examining their N–H stretching absorptions in the hydrogen-bonding system, the steric effects of the substituent on the C=O or N–H group have been studied for sym-disubstituted alkylureas of the RHNCONHR′ type in carbon tetrachloride. By comparing the estimated percentage of the monomer, it is concluded that the steric effects are not large enough to convert the trans conformation into the cis conformation, though the branched alkyl groups may prevent another molecule from approaching more strongly than the normal alkyl groups. Correlations among some spectral parameters have been examined, such as the estimated percentage of the monomer, the frequency shift upon hydrogen-bond formation, the apparent integrated absorption intensity, and the halfintensity width of the associated band.
The Electro-Initiated Polymerization of Acrylamide in an Aqueous Solution of Trifluoroacetic Acid and Potassium Trifluoroacetate
Authors: Ogumi Zenpachi , Tari Isao , Takehara Zenichiro , Yoshizawa Shiro 
Published: July 2006

Abstract
The electro-initiated polymerization of acrylamide was investigated in an aqueous solution of trifluoroacetic acid and potassium trifluoroacetate. An oligomer with a molecular weight of 4000–6000 was thus obtained. The initiating ability of Kolbe’s intermediate radicals was recognized by an analysis of the fluorine contained in the polymerized products as the end group. Kolbe’s intermediate radicals, R·, react with monomers, M, to form RM·, which takes the paths of polymerization and other reactions. The rate of reaction to form RM· is so fast that no Kolbe’s dimer, C2F6, is obtained. Gas analysis clarified the ratio of CF3COO· to CF3·, which reacted with the monomer. The comparison of the molecular weights as measured by the two different methods suggests that the coupling reaction of radical ends terminates the propagation reaction. The rate of oligomer production was independent of the current density.
Force Field of Allene
Authors: Tanabe Kazutoshi , Saëki Shinnosuke 
Published: July 2006

Abstract
The force constants based on the simple or modified Urey-Bradley, and the general force fields have been determined from the observed fundamental frequencies, Coriolis coupling constants and centrifugal distortion constants of allene C3H4, C3D4 and C3H2D2 by the damped least-squares method. It is concluded that the simple or modified UBFF is not suitable for reproducing the observed data. In order to attain the best fit between the observed and calculated values, new bond-angle interaction constants q(CH, CCC) and q(CC, HCH) as well as the bond-bond and angle-angle interaction constants p and l should be added to the simple UBFF.
The Microwave Spectrum of 3,3,3-Trifluoropropene
Authors: Saito Shuji , Makino Fumio 
Published: July 2006

Abstract
The microwave spectra of normal, 2–13C, and three monodeuterated isotopic species of 3,3,3-trifluoropropene have been studied. The combined structure of ro and rs was obtained from the rotational constants observed. It has been necessary to take account of a tilt angle of the symmetry axis of the trifluoromethyl group. The following structural parameters have been determined: r(C–C)=1.489±0.002Å, r(C=C)=1.312±0.010Å, r(C–H1)=1.085±0.011 Å, r(C–H2)=1.092±0.009 Å, r(C–H3)=1.109±0.003 Å, ∠F–C–F=106.8±0.3°, ∠C–C=C=124.8±0.4°, ∠C=C–H1=120.6±1.0°, ∠C=C–H2=122.8±1.0°, ∠C=C–H3=121.2±1.0°, and θt=1.0±0.8° on the assumption that r(C–F)=1.345±0.003Å, where θt denotes the tilt angle of the CF3 top axis relative to the C–C bond away from the double bond of the vinyl group. The components of the electric dipole moment have been determined to be μa=2.331±0.014 D and μb=0.698±0.025 D; these values give a total dipole moment of 2.433±0.020 D at an angle of 7±1° with the symmetry axis of the trifluoromethyl group. The relative intensity between the rotational transitions in the ground state and in the first torsionally-excited state has been measured. The torsional frequency has been determined to be 88±25cm−1.
The Reaction of Hot Deuterium Atoms with cis-2-Butene
Authors: Sato Shin , Nishida Seishi , Hosoya Kiyoshi 
Published: July 2006

Abstract
The photolysis of deuterium iodide at the wavelength of 2288 Å was carried out in the presence of cis-2-butene and iodine at 40 °C. Among the products, hydrogen (D2 and HD), methane (CH3D), propylene (CH3CH=CHD), n-butane (CH3CHDCHDCH3), and 1-butene were measured as a function of the pressure of cis-2-butene. The formation of HD at higher pressures of cis-2-butene was attributed to the abstruction of H atoms from cis-2-buteneby hot D atoms. This reaction accounted for 8% of the total D atom-reaction. The formations of CH3D, C3H5D, and C4H8D2 were well explained by the successive reactions of hot butyl radicals, C4H8D*.
The Radiolytic-chain Dechlorination of Polychlorinated Biphenyls in Alkaline 2-Propanol Solutions
Authors: Sawai Takeshi , Shimokawa Toshinari , Shinozaki Yoshiharu 
Published: July 2006

Abstract
The radiolysis of solutions of polychlorinated biphenyls (PCB’s) and potassium hydroxide in simple aliphatic alcohols was studied. The major products in alkaline 2-propanol solutions were potassium chloride, acetone, lower chlorinated biphenyls, and biphenyl. Their yields increased and the concentration of the hydroxide ions decreased with the dose. Acetone and potassium chloride were formed in high yields, and their concentrations were almost equal to the diminution in the hydroxide ions. The dechlorination yield was determined as a function of the dose, the dose rate, and the concentrations of PCB’s, potassium hydroxide, and organic solutes. The chain-dechlorination reaction proceeded in the alkaline 2-propanol solution, but not in alkaline methanol, ethanol, 1-propanol, and butanols. The 2-propoxide radical anion, which is formed by the electron transfer from the hydroxide ion to the 2-propanol radical, is the chain carrier for the dechlorination reaction of PCB’s in alkaline 2-propanol solutions. The mechanism is discussed in detail.
Photolysis of 2,2-Diethoxy-2,3-dihydrophenalene-1,3-dione
Authors: Otsuji Yoshio , Wake Shigeo , Maeda Eiichi , Imoto Eiji 
Published: July 2006

Abstract
Irradiation of 2,2-diethoxy-2,3-dihydrophenalene-1,3-dione (6) with a pyrex-filtered high-pressure Hg arc lamp afforded acetaldehyde, 2-ethoxy-3-hydroxyphenalene-1-one (7) and bis-2-(2-ethoxy-l,3-dioxo-2,3-dihydro) phenalenyl (8). Mechanistic studies revealed that the first step of this photoreaction was a homolytic fission of the C–OC2H5 bond to 2-(2-ethoxy-1,3-dioxo-2,3-dihydro)phenalenyl radical (9) and ethoxyl radical. This homolytic fission occurred mostly from the triplet and in part from the singlet excited state of 6. Dimerization of 9 gave 8 and the disproportionation between 9 and ethoxyl radical gave acetaldehyde and 7. The photochemical behaviors of a variety of triketone derivatives were discussed.