bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Stable 2,3-Dihydroindolizines by the Reactions of Pyridinium Methylides with Various Acrylates
Authors: Kakehi Akikazu , Ito Suketaka
Published: July 2006

Pyridinium methoxycarbonylmethylides(5–8), readily obtainable from their corresponding salts(1–4), reacted with various acrylates to afford dimethyl 2,3-trans-dihydroindolizine-1,3-dicarboxylate derivatives(9–20) in moderate yields. These dihydroindolizines were very stable and were not aromatized by heating. However, treatment with lead tetraacetate gave the corresponding indolizine derivatives(21–32) in good yields. The configuration at C-2 and C-3 positions in these dihydroindolizines was assigned to trans from their NMR and by comparison with an authentic specimen(12).
The Effects of the Composition of Raw Cadmium Sulfide on the Characteristics of Cadmium Pigments
Authors: Tsunashima Makoto , Takahashi Hiroshi
Published: July 2006

The effects of the S/Cd mol ratios of cadmium sulfide precipitates on the particle size, the hexagonality, and the brightness of cadmium pigments were studied. The precipitates were prepared by mixing an aqueous solution of cadmium nitrate with either sodium sulfide or hydrogen sulfide. Then, cadmium pigments were made of these precipitates by heat-treatment under an atmosphere of oxygen or nitrogen. The characteristics of the pigments were affected by the following three factors; particle size, hexagonality, and brightness. These factors were closely related to the S/Cd mol ratio of the precipitates of the cadmium pigments. We found the minimum points on the curves of the particle size, the hexagonality, and the brightness in relation to the S/Cd mol ratio. From these results, it was concluded that the optimum range of the S/Cd mol ratios of the precipitates for the characteristics of the cadmium pigments was 0.98±0.01.
Photocyclization of [2.2]Metacyclophane at 2537 Å
Authors: Sorimachi Kenji , Morita Toshifumi , Shizuka Haruo
Published: July 2006

The photochemical reaction of [2.2]metacyclophane at 2537 Å has been studied spectrophotometrically. Photocyclization took place to give 4,5,9,10-tetrahydropyrene not only in aerated but also in degassed solutions. The quantum yields for the reaction were independent of the irradiation time, concentration of starting material, light intensity, and addition of piperylene. However, the reaction quantum yields increased with temperature rise. The quantum yields in the aerated system were somewhat larger than those in the degassed system. Radiationless deactivation in S1(ππ*) was very efficient, whose quantum yield was assumed to be ∼0.99, judging from the small reaction quantum yield (less than 0.01) and the lack of fluorescence and phosphorescence. It is proposed that the photocyclization of the molecule originates from S1(ππ*) to give intermediate M which is subsequently convreted into the product or the starting material. Activation energies in these processes were estimated.
Photochemistry of the Electron Donor-Acceptor System. I. Exciplex Fluorescence and the Fluorescence of the Charge-Transfer Complex in the Aromatic Hydrocarbon–Fumaronitrile System
Authors: Shirota Yasuhiko , Tsushi Isamu , Mikawa Hiroshi
Published: July 2006

The fluorescence of a series of aromatic hydrocarbons was quenched by the addition of fumaronitrile, which is consistent with the charge-transfer or electron-transfer mechanism. The fluorescence quenching was accompanied by the appearance of a new, broad structureless emission band attributed to the fluorescence from the exciplex in non-polar or slightly polar solvents. In highly polar solvents only quenching of the fluorescence occurred. The energies of the band maxima of the exciplex fluorescences and the magnitude of the ionization potentials of a series of fluorescers showed a good correlation with each other. Solvent and temperature dependence of the exciplex fluorescence was examined and discussed. The present aromatic hydrocarbon-fumaronitrile system also formed a charge-transfer complex in their ground states at relatively high concentrations of each component. The selective excitation of the ground state charge-transfer complex gave rise to the fluorescence emission in a fluid solution at room temperature at the same wavelength region as observed for the exciplex fluorescence. It was susgested that the electronic structure of the fluorescent state of the exciplex and the excited charge-transfer complex is the same.
An MO Study on the Hydrogen Bond System of H2O–HF
Authors: Yamabe Shinichi , Kato Shigeki , Fujimoto Hiroshi , Fukui Kenichi
Published: July 2006

An LCAO MO SCF calculation has been carried out on H2O–HF system with a minimal STO-3G basis set, with respect to three assumed models, i.e. SIGMA, PI, and BIFURCATED models. A configuration analysis of the wave function has shown that charge-transferred electron configurations weakly mix into the original electron configuration in the SIGMA and PI models, while the contribution of charge-transferred configurations is negligibly small in the BIFURCATED model. The SIGMA model has been found to be most stable mainly due to the Coulombic attraction energy between the two species. The intermolecular electron density between the two interacting systems has been investigated by means of a concept of orbital interaction, leading to a conclusion that the mixing-in of the occupied MO’s of H2O with the unoccupied MO’s of HF contributes slightly to the hydrogen bond in the SIGMA and PI models.
Properties of Protective Films Formed on an Iron Surface by Dialkyl Phosphate as a Corrosion Inhibitor
Authors: Nakagawa Satoru , Hashizume Genzo
Published: July 2006

The properties of films formed on an iron surface by di-n-dodecyl phosphate were studied. The inhibition effects for iron specimens treated with dodecyl phosphate were estimated from the losses in weight of iron specimens in 5% NaCl aqueous solutions. The Fe Lα, Lβ X-ray emission spectra of the iron surface were obtained by electron microprobe X-ray analysis. The value of the intensity ratio, Fe Lβ/Lα, of the untreated iron specimen was 0.17, while that of the treated iron specimen was 0.28. The infrared spectrum of the treated iron surface was similar to that of tribasic orthophosphate. The content of Fe in the film formed on the iron surface by di-n-dodecyl phosphate was from 4.3% to 6.98%. From these results, it was inferred that di-n-dodecyl phosphate reacted with iron atoms at the iron surface in a cyclohexane solution and that the main component of the film formed on the iron surface was [(RO)2POO]2Fe or [(RO)2POO]3Fe.
Infrared Spectra and Structure of Substituted Unsaturated Carbonyl Compounds. XVIII. N-Alkyl-enamino Thiones
Authors: Dabrowska Urszula , Dabrowski Janusz
Published: July 2006

Skeletal and N–H bending vibrations have been investigated in enamino thiones having the general formula R1C(S)CH=C(R3)NHR4 (R=alkyl) and compared with those of the oxygen analogues (enamino ketones).
Dithiocarbamate Complexes of Rhodium(III), Iridium(III), Palladium(II) and Platinum(II)
Authors: Margotrigiano G , Pellagani G C , Preti C , Tosi G
Published: July 2006

The complexes of rhodium (III), iridium(III), palladium(II) and platinum(II) with piperidine-, piperazine-, N-methylpiperazine-, morpholine- and thiomorpholine-dithiocarbamate have been prepared and characterized by spectroscopic methods. From the electronic absorption spectra the values of the ligand field parameters were determined. The nephelauxetic parameters are indicative of a strong covalency in the metal-ligand bond. A monomeric structure for the complexes is suggested. All the new compounds here reported are diamagnetic.
A Flash Photolytic Investigation of the Interaction between Halide Anions and the Triplet Eosin
Authors: Akiyama Takeshi , Kamiya Mamoru , Akahori Yukio
Published: July 2006

The quenching effect of the iodide ion to the triplet eosin in oxygen-free aqueous solution was strongly enhanced at 10−1–10−2 M, but the effects of bromide and chloride ions were negligibly small at 10−1–10−4 M. The above-mentioned results were found directly by means of a flash photolytic method.
The Formation of Crystalline Molecular Complexes between Inosine and Several Phenols
Authors: Suzuki Yoshihisa , Hara Kentaro , Hirahara Tsuneo
Published: July 2006

Inosine has been found to form. 1:1 crystalline molecular complexes with phenol, p-nitrophenol, and 1,2,3-trihydroxybenzene respectively, and to be inactive with o-, m-nitrophenol, 1,2,4-, 1,3,5-benzenetriol, benzenediols, aminophenols, and cresols.
Molecular Vibrations and Force Fields of Alkyl Sulfides. XII. Skeletal Conformations of Several Simple Aliphatic Sulfides
Authors: Ohsaku Masaru
Published: July 2006

A normal coordinate treatment of methyl propyl, methyl butyl, ethyl propyl, ethyl butyl, and dipropyl sulfides has been carried out. From the observed and calculated frequencies, the conformation about each of six C–C bonds-—CSC–CC, CSC–CCC, CCSC–CC, CCSC–CCC, and CC–CSC–CC-— was confirmed to be the T form in the annealed crystalline state.
Formation of Hydrogen Gas with an Electrochemical Photo-cell
Authors: Fujishima Akira , Kohayakawa Koichi , Honda Kenichi
Published: July 2006

In an electrochemical photo-cell the use of a basic electrolyte solution in the TiO2 electrode compartment and an acidic one in the Pt cathode compartment can produce a high yield of hydrogen gas.
An Electron Paramagnetic Resonance Study of Low-Spin Five-coordinate Cobalt (II) Complexes
Authors: Nishida Yuzo , Kida Sigeo
Published: July 2006

EPR spectra were measured for the fivecoordinate cobalt(II) complexes, [CoCldpe2]SnCl3 and [CoCldpe2]SnCl3·C6H5Cl, which had been determined by X-ray analyses to have a tetragonal pyramidal and trigonal bipyramidal structures, respectively. The observed g-values showed a satisfactory agreement with the previously reported prediction.
Atomic Absorption Spectrophotometry of Titanium in the Iron Sulfides of NiAs Type
Authors: Ametani Kohei
Published: July 2006

A method is described for the atomic absorption spectrophotometric determination of titanium in the sulfides, Fe1−xTixS (x≤0.3), of NiAs type. Potassium sulfate was added to both sample and standard solutions to suppress the iron interference. The powder and single crystal samples were successfully analyzed using 10 mg of samples.
Fourier Analysis of AC Polarogaphy: Kinetic Parameters for Zn(II)-1 M NaClO4 and KCl Systems
Authors: Hirota Michio , Umezawa Yoshio , Fujiwara Shizuo
Published: July 2006

The fundamental and second harmonic responses of the Zn(II)/Zn(Hg) electrode agreed with the theory with respect to the phase angle. The ekinetic parameters of the systems were: ks=(2.8±0.3)×10−3cm/s, α=0.30±0.05 in 1 M NaClO4 and ks=(3.3±0.3)×10−3 cm/s, α=0.27±0.03 in 1 M KCl.
The Transisopropylation of Naphthalene
Authors: Shimada Keizo , Nagahama Shizuo
Published: July 2006

The transisopropylation of naphthalene with p-cymene and isopropylxylenes in the presence of aluminum chloride–nitromethane complex as a catalyst was studied. It was observed that the α-isomer initially formed was isomerized to the β-isomer in the reaction with isopropyl-p-xylene. However, when p-cymene or isopropyl-o-xylene was used, the isomer distribution was almost constant from the beginning to the end of the reaction. This was attributed to the fact that the hydride abstraction mechanism plays a role in the latter case.
The Structure of Tedanin, a New Carotenoid of Tedania digitata (O. Schmidt)
Authors: Okukado Nobuhisa
Published: July 2006

A new carotenoid, tedanin, which was isolated as a main pigment from a sea sponge, “Tedania digitata (O. Schmidt),” was shown to have the (I) structure by means of spectroscopic and chemical evidence.
Steric Interaction between the 1-Methyl and 9-Hydrogen of 1,2,3,4-Tetramethyldibenzofuran
Authors: Keumi Takashi , Oshima Yoshibumi , Tokura Niichiro
Published: July 2006

1,2,3,4-Tetramethyldibenzofuran was newly synthesized and the steric interaction between the hydrogen atom at the 9-position and the methyl group at the 1-position was examined from the nuclear Overhauser effects.
Synthesis of 1,3-Diaryl-1,2-propanedione by Dehydrochlorination of 3-Chloro-2-hydroxy-1,3-diaryl-1-propanone Catalyzed by Hydrogen Chloride
Authors: Uchida Takane , Miyagi Yo , Maruyama Kazuhiro
Published: July 2006

Dehydrochlorination of 3-chloro-2-hydroxy-1,3-diaryl-1-propanone proceeds to give 1,3-diaryl-1,2-propanedione in a high yield on heating its dioxane solution with a catalytic amount of hydrogen chloride. Kinetic studies were carried out.
Photochemical Reaction of Friedelin. Formation of an ε,ζ-Unsaturated Aldehyde
Authors: Shirasaki Hidekazu , Aoyagi Reiko , Tsuyuki Takahiko , Takahashi Takeyoshi , Stevenson Robert
Published: July 2006

Friedelin (1) in n-pentane or ethanol was irradiated using a high pressure mercury lamp under a nitrogen atmosphere. From the aldehydic fraction of the photolysate, an ε,ζ-unsaturated aldehyde, 10β-(2-formylethyl)-5α-vinyl-des-A-friedelane (5) has been isolated. Upon oxidation with silver oxide, 5 afforded putranjivic aqid (6).
A Novel Reduction of the O-(3,5-Dinitrobenzoyl)-N,N-(aroylary)hydroxylamines by the Cyanide Ion in Dipolar Aprotic Solvents
Authors: Oae Shigeru , Sakurai Tadamitsu
Published: July 2006

The reaction of O-(3,5-dinitrobenzoyl)-N,N-(aroylaryl)hydroxylamines with the cyanide ion in dipolar aprotic solvents was found to afford the corresponding reduction products, i.e., N-aroylarylamines, in good yields via decarboxylation. The mechanism of this novel reduction was discussed.
Fundamental Studies of Solvent Dyeing with Tetrachloroethylene. II. The Diffusion of 1,4-Dia minoa nth raqui none in Nylon 6
Authors: Morita Zenzo , Uchimura Koji , Motomura Hiromi
Published: July 2006

The diffusion and sorption of 1,4-diaminoanthraquinone in nylon 6 were investigated using a cylindrical film-roll. The diffusion of the penetrant in nylon 6 from the aqueous dyebath was much faster than that from the tetrachlororoethylene (TCE) dyebath. The surface concentration from water was larger than that from TCE. The water added to the TCE dyebatb accelerated the diffusion of the penetrant in nylon 6.
The Spin-Statistical Contribution in Redox Chemiluminescence Quantum Efficiency
Authors: Keszthelyi Csaba P
Published: July 2006

The theoretical upper limit of the quantum efficiency of Redox Ghemiluminescence is shown to be 1.0 for both energy sufficient and energy deficient systems; whether the oxidant and reductant are generated in situ (as in ECL) has no effect on the chemiluminescence efficiency.
Microdetermination of Olefinic Linkage by N-Bromosuccinimide
Authors: Sakla Alfy Badie , Abdou Sadek Elsayed , El-khadrawy Olfat Ahmed
Published: July 2006

A simple, accurate, and relatively rapid procedure for the estimation of olefinic linkage with N-bromosuccinimide has been presented.
Syntheses of Trinuclear Riitheniiim(III) Complexes with Dichloroacetato Ligands
Authors: Mukaida Masao , Kusakari Mitsumasa , Togano Tadashi , Isomae Toshihiro , Nomura Terunosuke , Ishimori Tatsujiro
Published: July 2006

Trinuclear ruthenium(III) complexes were prepared by the reaction of the dinuclear ruthenium(II, III) acetato complex with dichloroacetic acid. On the basis of chemical and thermal analyses, and on the basis of observations of the magnetic properties, the conductivities, the molecular weight, the alkalimetry, the infrared spectra and the electronic spectra, the complexes prepared here were formulated as [RU3O(CHCl2COO)6(CH3OH)3](CHCl2COO) and [Ru3O(CHCl2COO)6(OH)(H2O)2].
Optically-active Vibrations and Effective Charges of Calcite and Magnesite
Authors: Yamamoto Akio , Shiro Yuji , Murata Hiromu
Published: July 2006

A rigid-ion model analysis was made for the optically-active crystal vibrations of calcite (CaCO3) and magnesite (MgCO3) with reference to the previous vibrational treatments. The effects of the effective charge distribution on the TO–LO splittings of the lattice modes were examined on the proposed distribution model, and the effective charges have been found: Zca=1.21, Zc=0.20, and Zo=−0.47 in calcite, and ZMg=1.28, Zc=0.21, and Zo=−0.50 in magnesite, all in electron units. The force fields and effective charges determined in the present study reproduce satisfactorily the observed transverse and longitudinal frequencies of the optically-active lattice vibrations.
Surface Water Content of Metal Oxides. II. Measurement of Samples Containing Pores: Silica, Alumina and Silica-Alumina
Authors: Naono Hiromitu , Kadota Toshie , Morimoto Tetsuo
Published: July 2006

Two essentially different methods for determining surface water content, i.e., a successive-ignition-loss method and chemical reaction of active hydrogen with methylmagnesium iodide, were applied to the measurement of samples containing pores: silica, alumina, and silica-alumina. It was found that the rate of reaction of methylmagnesium iodide with active hydrogen largely depends upon the pore size distribution. It took 20 min for completion of the reaction on the Aerosil sample having no pores, ca. 1 hr for alumina and silica-alumina which have peaks in the pore size distribution curve at radii 53 and 37 Å, respectively, and 17 hr for porous silica glass and silica gel which have peaks at radii 22 and 19 Å, respectively. The results obtained by the two methods were in good agreement with each other irrespective of the existence of pores in the transitional range. It was confirmed that the nature of the sample is decisive for the population of water content on metal oxides.
An ESR study of the Role of CoO and NiO in Al2O3–MoO3–CoO (or NiO) Desulfurization Catalysts
Authors: Ueda Hisashi , Todo Naoyuki
Published: July 2006

The ESR spectra from the catalyst/perylene/purified-benzene system were studied. The surface equilibria, Co3++P\ightleftharpoonsCo2++P+, Ni3++P\ightleftharpoonsNi2++P+, and Mo6++P\ightleftharpoonsMo5++P+, have been established, with the equilibrium constants at 20°C, 3.3×1015, 3.0×1014, and 6.8×109 respectively. In Al2O3–MoO3–CoO, Mo6++Co2+\ightleftharpoonsMo5++Co3+, is attained; the equilibrium constant obtained was 2.0×10−6, and the corresponding value for Mo6++Ni2+\ightleftharpoonsMo5++Ni3+ was 2.3×10−5. These results indicate that the roles of NiO and CoO in these catalysts are essentially the same. It has been found that the supporting order was important when CoO and MoO3were supported together, but unimportant when NiO and MoO3 were supported together. Considering the known fact that CoO is a more efficient Co-catalyst of MoO3 than NiO at lower supported concentrations (less than 2%), it has been concluded that CoO is incorporated in the alumina-carrier surface less stereospecifically, but more effectively, than NiO.
Reaction of 2-Halo-1-Olefin-1-Carboxylic Acid with Cu2O and Isonitrile
Authors: Ito Yoshihiko , Konoike Toshiro , Fujii Syotaro , Setsune Junichiro , Saegusa Takeo
Published: July 2006

A reaction of 2-halo-1-olefin-1-carboxylic acids with isonitrile and Cu2O is described. o-Chlorobenzoic acid is treated with ter-butyl isocyanide and Cu2O at 80°C to produce benzoic acid (1a), phthalic anhydride (2a), N-tert-butylphthalisoimide (3a) and N-tert-butylphthalimide (4a) in 5, 14, 18, and 32% yields, respectively. With 2-chloro-1-cyclohexene-1-carboxylic acid, a similar result is observed. However, the reaction of acyclic 2-chloro-1-olefin-1-carboxylic acid such as β-chlorocrotonic acid with isonitrile and Cu2O does not give any products corresponding to 1—4. These reactions are interestingly compared with the reaction of o-iodobenzoic acid and copper-(I) acetylide producing 3-alkylidenephthalide. A reaction mechanism involving a transient intermediate of α,β-unsaturated β-lctone (11) is proposed for the present reaction.
Studies of the Catalytic Properties of Synthetic Zeolite A. IV. The Thermal Stability of Silver-exchanged Zeolite A
Authors: Matsumoto Shigemi , Nitta Masahiro , Ogawa Kiyoshi , Aomura Kazuo
Published: July 2006

The effects of the degree of exchange and the dehydration upon the structural stability of silver-exchanged forms of the synthetic zeolite Linde 4A have been investigated by means of DTA, X-ray diffraction, and adsorption studies. The relative intensity of the X-ray powder diffraction decreased with an increase in the extent of Ag+-exchange, though it indicated no accurate information on the crystallinity. An exotherm on the DTA curves which shifted to a lower temperature with the degree of exchange became an indication of the collapse of the structure; this was in good agreement with the specific surface area of the sample heated at a higher temperature. From these results, the silver-exchanged zeolite A was concluded to be thermally unstable and to lose its crystal structure at a lower temperature than the original sodium form. It is also proposed that the comparison of the X-ray powder diffraction intensity is not suitable as a method for judging the crystallinity of zeolites A.
Conformations of Sequential Polypeptides of l-Leucine and Glycine in Solution
Authors: Iio Takayoshi , Takahashi Sho
Published: July 2006

With the aid of optical rotatory dispersion, circular dichroism, and infrared spectra, the conformations of the sequential polypeptides of l-leucine and glycine, (Leu3Gly)n, (Leu2Gly)n, (LeuGly)n, and (LeuGly2)n, were studied and compared with the conformation of poly-l-leucine. It was shown that the polymers (Leu)n, (Leu3Gly)n, (Leu2Gly)n, and (LeuGly)n could be α-helical in solution, but (LeuGly2)n was not. The order of the stability of the α-helix of these polymers was found to be: (Leu)n>(Leu3Gly)n∼(Leu2Gly)n>(LeuGly)n>(LeuGly2)n. This was attributed to interactions between side chains of l-leucines which were regularly arranged on the α-helix.
Liquid-phase Oxidation Catalyzed by Cu(II)–Cl. II. Chloride Ion Transfer during the Oxidation of Cyclohexene
Authors: Imamura Sei-ichiro , Otani Takafumi , Teranishi Hiroshi
Published: July 2006

Cyclohexene was oxidized in glacial acetic acid with a Cu(II)–Cl catalyst. In addition to the main oxidation products, 3-cyclohexenyl chloride, 3-cyclohexenyl acetate, 2-chlorocyclohexanol-(1), cyclohexene oxide, and hydrogen chloride were produced. The mechanism of the formation of these compounds was investigated in detail: the deactivation of the catalyst was explained by chloride ion transfer.
Syntheses and Properties of Crosslinked Ferrocene Polymers
Authors: Omori Mamoru , Kurono Masayasu , Yajima Seishi
Published: July 2006

The polycondensation reaction of acetylferrocene and furfural was investigated in the presence of concentrated H2SO4 as a catalyst without solvent. Stoichiometric reaction took place with 2 mol of acetylferrocene and 5 mol of furfural. Polycondensation afforded satisfactory results when 1 mol of acetylferrocene was treated with 2–7 mol of furfural. The structural evidence for these products was derived from chemical and infrared analyses. Density, micro Vickers hardness, magnetic susceptibility, and thermal behavior of these products were measured in comparison with those of other resins.
Formation of 9,9′:9′,9″-Terfluorenyl Isomers Using Metalated Fluorenes as Synthetic Intermediates
Authors: Minabe Masahiro , Suzuki Kazuo
Published: July 2006

Rotational isomers of 9,9′: 9′,9″-terfluorenyl were obtained by the addition of 9-lithiofluorene to 9,9′-bifluorenylidene (III). 2,7-Dibromo- (VI) and 2,7,2″,7″-tetrabromo-9′,9″-terfluorenyl (VIII) resulted from similar reactions of the corresponding bromo-derivatives. 9-Lithio-9,9′-bifluorenyl was treated with 9-bromo-9,9′-bifluorenyl to give 9,9′-bis(9,9′-bifluorenyl) (X), 9,9′: 9′,9″-terfluorenyl isomers (mp 293 °C (dec) (I) and mp 257 °C (dec) (II)), 9,9′-bifluorenyl (IX), III, and fluorenone. The isomerization of I by metallic potassium gave the other rotamer II, which decomposed into its components, IX, III, and fluorene (IV).
Multifunctional Hydrolytic Catalyses. III. Catalytic Hydrolysis of p-Nitrophenyl Acetate by Imidazole-4-carbohydroxamic Acids
Authors: Kunitake Toyoki , Horie Seiji
Published: July 2006

Imidazole-4-carbohydroxamic acids (I) and its N-methylhydroxamic acid derivative (II) were synthesized from imidazolecarboxylic acid and hydroxylamines, and the catalytic hydrolysis of p-nitrophenyl acetate was studied. The reaction was analyzed by the pseudo-first-order kinetics and the burst kinetics. The hydrolysis proceeds via the formation and the subsequent decomposition of the acetyl hydroxamate intermediate. The acylation rate with these catalysts were comparable to those observed with other simple hydroxamic acids. On the other hand, the deacylation of the acetyl intermediate of II was greater than expected and increased with pH. This suggests that the intramolecular imidazole group (neutral and/or anionic species) assists deacylation, thus increasing the overall efficiency of catalysis.
Photolysis of p-Benzoquinone in Aqueous Solution. Possibility of a Polar Mechanism in the Primary Process
Authors: Shirai Masamitsu , Awatsuji Toshio , Tanaka Makoto
Published: July 2006

The photochemistry of p-benzoquinone in water was investigated spectrophotometrically. The effect of p-nitroso-N,N-dimethylaniline as an additive confirmed a non-radical mechanism. The small positive deuterium isotopic effect suggests an electrophilic attack of the excited p-benzoquinone on water.
Syntheses of Fluorine-Containing Chromans: A Radical Cycloaddition of Phenyl Alkyl Ethers with Hexafluoropropene
Authors: Kimoto Hiroshi , Muramatsu Hiroshige , Inukai Kan
Published: July 2006

Four 2-substituted 4-trifluoromethyl-3,3,4-trifluorochromans were synthesized in one step by the radical cycloaddition of phenyl alkyl ethers and hexafluoropropene in the presence of di-t-butyl peroxide.
A Novel Synthesis of l-Pipecolic Acid
Authors: Fujii Toshiyuki , Miyoshi Muneji
Published: July 2006

A novel synthesis of l-pipecolic acid from l-lysine is described. Bromination of ε-NH2 group on Nα-tosyl-l-lysine, followed by cyclization with NaH in DMF gave N-tosyl-l-pipecolic acid in 45% yield.
A Study on Electronic Spectra of Organic Compounds with S–Cl Group
Authors: Yamabe Tokio , Nagata Shinichi , Kikuzono Yasuo , Fukui Kenichi
Published: July 2006

MO calculations were carried out for CH3SCl, C6H5SCl, and related compounds with the S–Cl group by the CNDO/2 or the ASMO-SCF method. The absorption bands in the 300–400 nm region observed were assigned to the σS-Cl*←nS transition in view of transition energy and oscillator strength. Such characteristic bands are attributed to the extraordinarily low energy level of the σS-Cl* orbital.
Charge-transfer Complexes of Vinyl Polymers with Large Pendant π-electron Systems. I. Poly(N-vinylcarbazole) and Related Compounds
Authors: Okamoto Ken-ichi , Ozeki Miyuki , Itaya Akira , Kusabayashi Shigekazu , Mikawa Hiroshi
Published: July 2006

The absorption spectra and the thermodynamic constants (KCT, ΔH, and ΔS of formation) of the charge-transfer (CT) complexes of poly-N-vinylcarbazole (PVCz), the oligomers of N-vinylcarbazole (VCzOlig I and II, ‾DP=5 and 10 respectively), poly-N-carbazolylethylvinylether (PCzEVE), and the monomeric model compounds were examined in solution in order to clarify the characteristics of the complexes of polymeric donors with large pendant π-electron systems. The apparent spectra were resolved into two CT bands. The complexes of PVCz and VCzOlig II showed a lower frequency shift in the absorption maximum of the first CT band and an increase in the intensity ratio of the first to the second CT bands as compared with those of the monomeric complexes. This behavior, regarded as a kind of so-called polymer effect, seems to arise from some electronic interaction between neighboring carbazolyl groups in one polymer chain; it can be explained by variation both in the electron-donating character and in the distribution of the orientational isomers between the PVCz complexes and the others. A comparison of the observed values of KCT, ΔH, and ΔS among the donors suggested that a dominant factor in determining these values is the steric hindrance rather than the small difference in the electron-donating character in the case of the structurally related polymeric complexes. The steric hindrance is important in the complexes of PCzEVE and VCzOlig I, where the electronic interaction is hardly present.
Simple and Complex Anion-radical Salts Derived from 2,3-Dicyano-1,4-naphthoquinone
Authors: Maki Izumi , Matsunaga Yoshio , Nakakura Mitsuru , Nonaka Akihiko
Published: July 2006

Simple and complex anion-radical salts were prepared by the reduction of 2,3-dicyano-1,4-naphthoquinone with a number of onium iodides. The simple salts are green-colored, and the complex salts, with a composition of 1: 2, are dark green or brown. The latter salts show electronic absorptions extending into the near-infrared region. The electrical resistivities are rather high— 107–1012 ohm cm in the simple salts and 103–107 ohm cm in the complex salts. The ESR spectra characteristic of triplet excitons were observed with polycrystalline samples, and the zero-field splitting parameters and the singlet-triplet separation energies were estimated for most of the salts. The anion-radicals appeared to be in strong pair-by-pair interactions in these salts.
An X-Ray Analysis of the Orientational Disorder of N-Methylphenazinium-TCNQ
Authors: Kobayashi Hayao
Published: July 2006

The X-ray diffraction patterns of NMP-TCNQ show diffuse streaks along the c* direction. The analysis of the intensities of these streaks revealed that the orientation of NMP is one-dimensionally disordered along the c axis. The structure obtained indicates that the potential exerting on an electron moving in a column of TCNQ is not random, but can be expressed by a periodic function; this implies that NMP-TCNQ, can not be regarded as a disordered one-dimensional conductor. The periodicity of the potential means that the one-dimensional energy band must be filled.
Electron Transfer Reaction in the Triplet State. Role of Ferrocene as an Electron Donor
Authors: Kikuchi Koichi , Kokubun Hiroshi , Kikuchi Masae
Published: July 2006

Quenching of the triplet state of methylene blue by ferrocene and p-phenylenediamine in ethanol has been investigated by an emission-absorption flash technique. The triplet dye is quenched by ferrocene and p-phenylenediamine at a diffusion-controlled rate, yielding the semi-reduced dye. Efficiency of the semi-reduced dye formation is 0.09 and 1.0 for ferrocene and p-phenylenediamine, respectively. Since the triplet level of the dye is lower than that of ferrocene, quenching of the triplet dye by ferrocene seems to occur through the charge (electron) transfer interaction.
The Micelle Formation of Mixtures of Polyoxyethylene Type Nonionic Surfactants in Aqueous Solutions
Authors: Nishikido Nagamune , Moroi Yoshikiyo , Matuura Ryohei
Published: July 2006

The critical micelle concentrations (CMC) of mixtures of nonionic surfactants with the same hydrocarbon, i.e. dodecyl group, and with various chain lengths of ethylene oxide, were determined. The observed values were compared with the values calculated by means of the equation derived from the pseudo-phase separation model on the assumption that the mixed micelle is a perfect solution. A good agreement between observed and calculated values was obtained in the mixtures of the surfactants with six or more ethylene-oxide units. However, the observed values of the two-component mixture, one component with five ethylene-oxide units, showed a small deviation from the calculated values. The difference between the above two cases was explained from the viewpoint of the most suitable packing of the first six or fewer ethylene-oxide units near the micelle core in the micelle state.
Basic Properties of Metal Phosphates and Their Catalytic Activity in the Decomposition of Diacetone Alcohol
Authors: Tada Akio
Published: July 2006

The basic properties of alkali and alkaline earth metal phosphates calcined at various temperatures were investigated. The strength of the surface base was determined by the adsorption of acidic indicators from benzene solution. It was found that K3PO4 shows a fairly high basic strength of H0≥17.2. The surface basicity was evaluated by the catalytic activity for the decomposition of diacetone alcohol, which is known to be catalyzed only by basic catalysts. Comparison of the result of the activity measurement with that of TGA indicated that the basicity of a metal phosphate reaches a maximum when dehydrated completely. The nature of the basic sites on metal phosphates is also discussed.
An Electron Spin Resonance Study of the Anion Radicals of Some Nitrotropolonates and 2-Methoxy-5-nitrotropone
Authors: Ikegami Yusaku , Seto Shuichi
Published: July 2006

The anion radicals of 5-nitro-, 3-nitro-, and 3,5-dinitro-tropolonates and of 2-methoxy-5-nitrotropone were generated electrolytically in N,N-dimethylformamide. Hyperfine structures of these ESR spectra were reasonably interpreted with the spin density calculations. The results for the 3-nitro- and 3,5-dinitro-tropolonates suggested that the 3-nitro groups were twisted about 40 and 55°, respectively, from the ring plane.
The Heating-rate Dependence of the Mechanical Properties of Several Polymers at Higher Temperatures
Authors: Furusho Noboru , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

Measurements of the mechanical properties of various polymers at higher temperatures under the conditions of several heating rates were carried out in the air using the torsional braid analysis (TBA) method. It has become apparent that the examples of the dependence of the mechanical properties upon the heating rate at higher temperatures are classified into two groups. The first is characterized by the fact that the temperature of the maximum in the logarithmic decrement remains unchanged, irrespective of any changes in the heating rate. This situation is related to the physical process. On the other hand, in the case of the second group, the TBA curves are shifted to higher temperatures with an increase in the heating rate; this is the results of chemical processes. A kinetic treatment of thermal analysis, in which kinetic parameters can be calculated from the heating-rate dependence of the characteristic point in the observed curves, was used in the present study. From this analysis, the apparent activation energies of the thermal degradation of polymers were obtained, and comparisons of these values with those from the isothermal measurements were made.
Synthesis and Proton Magnetic Resonance Spectra of Some Dichloro(picolinaldimine)palladium(II) and -platinum(II) Complexes
Authors: Kawakami Katsuhiko , Ohara Takeshi , Matsubayashi Gen-etsu , Tanaka Toshio
Published: July 2006

A series of dichloro(picolinaldimine)palladium(II) and -platinum(II) complexes was prepared. The PMR parameters, the chemical shifts of the ligand protons and the coupling constants between the platinum-195 nucleus and protons attached to carbons adjacent to donor nitrogens of the ligands, are discussed in the light of the metalto-ligand bonds.
The Coprecipitation of Strontium with Hydroxyapatite
Authors: Fujino Osamu
Published: July 2006

The distribution behavior of the strontium ion between hydroxyapatite and the parent solution was investigated. The hydroxyapatite was formed by the extremely slow addition of diammonium hydrogenphosphate to solutions of calcium and strontium nitrate buffered with ethylenediamine at 80 °C. The precipitate yielded a typical X-ray diffraction pattern of hydroxyapatite and had a composition in which the Ca/P molar ratio was 1.67 at pH 6.80. The strontium ion was coprecipitated in the apatite, obeying the Doerner and Hoskins logarithnmic distribution law. The distribution coefficient was scarcely affected by the strontium concentration on the pH value in the parent solution, and had a value of 0.26±0.02 at 80 °C. On the other hand, the apparent distribution coefficient was a little affected by such organic anions as acetate, citrate, lactate, glycinate, and glutamate ions. The lattice constants of the precipitates prepared in the research were measured in order to confirm the formation of the solid solutions.
Chemical Vapor Deposition of Tetraboron Silicide Whiskers
Authors: Motozima Seizi , Sugiyama Kozoh , Takahashi Yasutaka
Published: July 2006

Growth conditions of B4Si whiskers were investigated at the temperature range of 1000–1100 °C. Optimum composition of halides was determined as BCl3/SiCl4=2–0.5, and BCl3=1–6 vol% SiCl4=1–7 vol%. Gold had an excellent impurity effect with optimum concentration of 20–50 μg/cm2 on whisker growth, and gave wool like whiskers of 0.1–1 μm in thickness and 0.5–2 mm in length. B4Si whisker growth was explained in terms of a tip VLS mechanism, for a drop-like deposit of impurity was observed on each tip.
Nuclear Magnetic Resonance Studies of Bicyclic Thiophene Derivatives. I. Ring Current Effects of the Benzene Ring on the Hα and Hβ Signals of the Thiophene Ring in Benzoylthiophene, Thienopyrimidine and Thienodiazepine Derivatives
Authors: Hirohashi Toshiyuki , Inaba Shigeho , Yamamoto Hisao
Published: July 2006

Various thiophene derivatives such as 4-phenyIthienopyrimidines (1), 2-acetylamino-3-benzoylthiophenes (2), 5-phenyl-1,4-thienodiazepines (3) and 5-phenyl-1,4-thienodiazepine-4-oxides (4) have been prepared. Their proton magnetic resonance spectra show that Hα and Hβ of the thiophene ring become more shielded with an increase in bulk of ortho substituent of the benzene ring. This is attributed to the shielding effect of the benzene ring; a steric repulsion between ortho substituent of the benzene ring and some atoms on another moiety of each molecule. Such a repulsion should bring the benzene ring out of the plane of the thiophene ring. The degree of shielding on Hβ by the benzene ring is found to increase in the order 1<2<3<4. This can be taken to indicate that the amount of steric repulsion depends not only on the bulk of ortho substituent of the benzene ring but also on the geometry of each ring system of 1–4.
The Isomerization of the Stable Rotamers of 9,9′: 9′,9″-Terfluorenyls
Authors: Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The conformational change of the s-cis, s-trans-9,9′: 9′,9″-terfluorenyl to the s-cis, s-cis form via the radical process was performed by means of a reaction with N-bromosuccinimide and with various oxidizing agents. A reverse change occurred on treatment with lithium aluminum hydride and with sodium bis(2-methoxyethoxy)aluminum hydride.
The Thermolysis and Photolysis of 6-(Benzylidenehydrazino)uracils. New Syntheses of Pyrazolo[3,4-d]pyrimidines. A Method to Convert Aldehydes to Nitriles
Authors: Yoneda Fumio , Nagamatsu Tomohisa
Published: July 2006

The thermolysis of 6-(benzylidenehydrazino)uracil derivatives generally involves their oxidative cyclization to give the corresponding pyrazolo[3,4-d]pyrimidine derivatives. However, the thermolysis of fully methylated 6-(benzylidenehydrazino)uracils gave no pyrazolo[3,4-d]pyrimidines, but mixtures of the respective nitriles and 1,3-dimethyl-6-methylaminouracil. The photolysis of the fully methylated 6-(benzylidenehydrazino)uracils give the desired pyrazolo[3,4-d]pyrimidines.
The Intramolecular Participation of Sulfide Linkage on the Reactivity of Carbenes and Diazoalkanes. II. Alkylcarbenes and Diazoalkanes Bearing Arylthio and Allylthio Groups on β-Carbon
Authors: Kondo Kiyosi , Ojima Iwao
Published: July 2006

β-Arylthio- and β-allylthioalkylcarbenes were generated from the corresponding ketones by a modification of the Bamford-Stevens method. Chemical evidence for the formation of novel cyclic ylides, i.e., thietanonium ylides, by an intramolecular electrophilic addition of the carbene to the sulfur atom was obtained. The resulting ylides underwent various types of rearrangements to afford cyclopropyl sulfides, thiaazulenes, thietanes, and/or tetrahydrothiophenes. The mechanisms and the relative amounts of the transition energies for these rearrangements are discussed. An intramolecular cycloaddition of β-allyl- and β-crotylthioalkyldiazoalkanes is also described. The final products of the reaction were 3-thiabicyclo[4.1.0]heptanes. A thiabicyclic pyrazoline, which is presumed to be an intermediate of the cycloaddition, could be isolated in the case of the thermal decomposition of 4-allylthio-4-methylpentan-2-one tosylhydrazone.
The Reduction of Enamines with Carbonylhydridoferrates
Authors: Mitsudo Take-aki , Watanabe Yoshihisa , Tanaka Masato , Atsuta Shoji , Yamamoto Kazuo , Takegami Yoshinobu
Published: July 2006

Enamines react with an alcoholic solution of [FeH(CO)4]− (1), [Fe2H(CO)8]− (2), and [Fe3H(CO)11]− (3), with the absorption of carbon monoxide at room temperature, to give the corresponding saturated tertiary amines. The reduction of the pyrrolidine enamine of 2-methylcyclohexanone with 1, 2, and 3 gave cis and trans  N-(2-methyl-1-cyclohexyl)pyrrolidine. The cis/trans ratio of the products were characteristic of 1, 2, and 3; the values, 0.67, 1.2, and 2.1 respectively, represent the bulkiness of the hydrides. The mechanism of the reduction was discussed.
Synthetic Studies on Phosphorylating Reagent. IV. A Novel Synthesis of Nucleoside-3′,5′ Cyclic Phosphates by the Use of 2-(N,N-Dimethylamino)-4-nitrophenyl Phosphate
Authors: Taguchi Yoshihiko , Mushika Yoshitaka
Published: July 2006

A novel method for the synthesis of nucleoside-3′,5′ cyclic phosphate has been investigated. The intermediates, nucleoside-5′ 2-(N,N-dimethylamino)-4-nitrophenyl phosphates (3a–d), were prepared in good yields by the condensation of unprotected nucleosides with 2-(N,N-dimethylamino)-4-nitrophenyl phosphate (2), using dicyclohexylcarbodiimide (DCC) in dimethylformamide (DMF). Treatment of the intermediates 3a–d with acetic acid in boiling pyridine under high dilution condition gave nucleoside-3′,5′ cyclic phosphates in fairly good yields and small amount of other nucleotides, whereas nucleoside-2′,3′ cyclic phosphate was obtained by the reaction in DMF at 100 °C. An attempt at the direct synthesis of the cyclic nucleotide by refluxing the reaction mixture of unprotected nucleoside with DCC and 2 in pyridine was also successful to afford the similar results as in the stepwise procedure.
A Macrocyclic Enzyme Model System. Substrate Specificity for the Inclusion into Paracyclophane Oxime and the Subsequent Acyl Transfer Reaction
Authors: Murakami Yukito , Sunamoto Junzo , Okamoto Hiroshi , Kawanami Kiyomiki
Published: July 2006

In order to characterize the intrinsic nature of 10-hydroxy-11-hydroxyimino[20]paracyclophane (Oxime-I) as being an enzyme model, the acylation reactions of Oxime-I with p-nitrophenyl carboxylates have been investigated in an alkaline aqueous acetone. The usual saturation-type kinetics has been observed for the reactions of p-nitrophenyl decanoate (PNPD), laurate (PNPL), and palmitate (PNPP) with Oxime-I. The acyl transfer reaction was consistent with the following two sequences: (la) pre-equilibrium formation of the inclusion complex between Oxime-I and a substrate, (lb) pre-equilibrium acid dissociation of the inclusion complex, and (lc) rate-determining acyl transfer from a substrate to Oximate-I in the inclusion state; and (2a) pre-equilibrium acid dissociation of Oxime-I, (2b) pre-equilibrium formation of the inclusion complex between Oximate-I and a substrate, and (2c) rate-determining acyl transfer from a substrate to Oximate-I in the inclusion state. On the basis of the compensation correlation between enthalpy and entropy for binding process, the inclusion of a long chain carboxylate into the cavity of Oxime-I is controlled by entropy. It is interesting to note that the binding constants for the present inclusion complexes are considerably larger (K\simeq104–105 M−1) than those for the complexes formed between phenyl esters or azo dyes and cycloamyloses (K\simeq102–103 M−1). Thus, the paracyclophane skeleton provides an effective binding site due to the hydrophobic cavity. Since the most stable inclusion complex was formed with PNPD, the inclusion of the present esters may be not exclusively due to the hydrophobicity provided by an apolar hydrocarbon tail, but significantly due to the molecular geometry or bulkiness characterized by the folded ester molecule. This effect approves the presence of substrate specificity due to the molecular geometry for Oxime-I. In reference to the activation parameters, the acyl transfer process is controlled by entropy in a manner similar to the alkaline hydrolysis in the bulk phase and the complex formation as well. PNPP is least stabilized in the binding process due to the most unfavorable entropy effect, whereas most favorably deacylated in the acyl transfer due to the entropy factor. Consequently, the net change in the free energy is largely reflected on the entropy term. The deceleration effect observed in the reaction of PNPD with Oxime-I at a higher acetone content and the kinetic behavior of alkaline hydrolysis of the three carboxylate esters have also been discussed.
Autoxidation of Toluic Acids Catalyzed by Cobalt and Bromide Ions in Acetic Acid
Authors: Kamiya Yoshio , Ushiba Toshisuke
Published: July 2006

The effect of toluic acid concentration on the rate of autoxidation of toluic acids catalyzed by cobalt acetate and sodium bromide was elucidated. p-Toluic acid has shown a similar reactivity against oxidation to m-toluic acid, but a much different one from o-toluic acid. Although the rate of oxidation of p-toluic acid at 0.023 M cobalt increased with increasing p-toluic acid concentration and appeared to reach a limiting value, it was of first order with respect to the substrate concentration over wide range of concentration in the presence of 0.058 M cobalt. While, the rate of oxidation of o-toluic acid has shown higher values than the other toluic acids at substrate concentrations below 1.5 M and a maximum value at substrate concentration 0.75 M, suggesting that o-toluic acid can be oxidized easily but retards the catalysis by cobalt bromide. It was found that benzenecarboxylic acids remarkably retard the catalysis by cobalt and bromide ions, and the rate of oxidation of toluic acids is higher than that of toluene at such a low substrate concentrations as 0.34 M. The ease of oxidation of toluic acids can be attributed to the smaller rate constant of termination of carboxy benzyl peroxy radicals according to the polar and steric effects.
Carbon-Carbon Bond Formation by Selective Coupling of Alkylthioallylcopper Reagent with Allylic Halides
Authors: Oshima Koichiro , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

The reaction of 1-alkylthioallylcopper reagents with allylic halides affords the SN2′ type substitution product in excellent yield. The more synthetically useful reagent, 1,3-bis(methylthio)allylcopper reagent behaves in the same fashion. Attempts to hydrolyze the vinyl sulfide moiety to an aldehyde unit is successful only in the latter case. Yomogi alcohol is synthesized stereospecifically in the light of these results.
Steric Requirements in Base-Promoted Elimination Reactions
Authors: Ishizawa Akio
Published: July 2006

The effect of the steric requirement of the attacking base in base-promoted elimination reactions was studied using a variety of pairs of diastereoisomeric bases. The pairs of diastereoisomeric alkoxide bases examined gave difinitely different cis-olefin to trans-olefin ratios from elimination reactions of secondary alkyl bromides and tosylates in dimethyl sulfoxide. The results indicate unambiguously that the steric requirement of the attacking base is an important controlling factor in determining the olefinic product distribution in these elimination reactions. The structural effect of the solvent molecule was also investigated using pairs of diastereoisomeric alcohols in base-promoted elimination reactions. Under a variety of conditions the effect upon the product distribution observed was rather small, as compared with those observed for the diastereoisomeric bases, to be an important contributing factor on the product distribution.