bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of the Decarboxylation of Benzylmalonic Acid, Ethylmalonic Acid, and Dimethylmalonic Acid in Hydroxylic Solvents
Authors: Biswas Mihir K , Majumdar Dilip K
Published: July 2006

Kinetics of the decarboxylation of benzylmalonic acid, ethylmalonic acid, and dimethylmalonic acid have been shown to follow first order rate equation in several solvents, namely alkanediols and diethylene glycol (DEG), polyethylene glycol (PEG), and polypropylene glycol (PPG). The enthalpy and entropy of activation for the decarboxylation reactions were determined and the plot of ΔH\eweq  vs. ΔS\eweq was found to be linear through all the solvents.
A Novel Preparation of Bicyclo[3.2.2]nonanes and Bicyclo[4.2.2]decanes Substituted at the Bridgeheads
Authors: Sakai Yasuo , Terashima Kaoru , Tobe Yoshito , Odaira Yoshinobu
Published: July 2006

A novel preparation of 1,5-disubstituted bicyclo[3.2.2]nonanes and 1,6-disubstituted bicyclo[4.2.2]decanes based on the one-pot reaction of [3.2.2]- and [4.2.2]propellanecarboxylic acids with 2 equiv. of lead tetraacetate, followed by catalytic hydrogenation, is described.
Studies on the Complex Formation between o-Quinones and Metal Chlorides in Nitromethane Solution
Authors: Kataoka Kazuaki , Kimura Sumihisa , Shirakawa Fumiko , Sasaki Yoshio
Published: July 2006

Complex formation between several kinds of metal chlorides and 4,5-dimethoxy-1,2-benzoquinone (1) or 4-methoxy-1,2-naphthoquinone (2) has been studied by means of NMR and spectrophotometry in CH3NO2. Stability constants of the 1 : 1 complex were found to decrease in the order of SnCl4>InCl3>ZnCl2>BiCl3>SbCl3>HgCl2. ΔδML and Δνmax, which indicate the change in the chemical shift and the wavenumber on the formation of the 1 : 1 complex, were also arranged in the above order. The same order was reproduced from an electrostatic potential. Both ΔδML and Δνmax were proved to be a convenient scale for the relative acceptor strength of metal chlorides. For the basicity of o-quinones, the order of 1>2 was obtained from the thermodynamic data and from the negative charge on the carbonyl oxygens. The solute-solvent interaction model was also found appliciable in this system.
Interaction between Pyrazine and Halomethanes. I. Complex Formation between Pyrazine and Halomethanes at Room Temperature
Authors: Kuroi Tatsuaki , Gondo Yasuhiko , Kuwabara Masamichi , Shimada Ryoichi , Kanda Yoshiya
Published: July 2006

The absorption spectrum of pyrazine has been studied at room temperature in various mixed solvents of cyclohexane and halomethanes such as carbon tetrachloride, chloroform and dichloromethane. With increasing concentration of halomethane, the singlet-singlet (S-S) and singlet-triplet (S-T) n→π* absorptions decrease in intensity and become structureless, whereas the S-S π→π* absorption remains essentially unchanged. The observations are attributed to the complex formation between pyrazine and halomethanes involving the non-bonding electrons in pyrazine. From the concentration and temperature dependences of the n→π* absorption spectra, the equilibrium constants, enthalpy and entropy changes have been obtained for the complex formation in all the systems studied. The equilibrium constants obtained from the S-S and S-T n→π* absorptions are in good agreement with each other.
Interaction between Pyrazine and Halomethanes. II. Effects of Halomethanes on the Phosphorescence of Pyrazine at 77 K
Authors: Kuroi Tatsuaki , Gondo Yasuhiko , Kuwabara Masamichi , Shimada Ryoichi , Kanda Yoshiya
Published: July 2006

The phosphorescence and phosphorescence excitation spectra of pyrazine have been studied at 77 K in various mixed solvents of cyclohexane and halomethanes such as carbon tetrachloride, chloroform, and dichloromethane. When the halomethane concentration was low (below 10−2 mol dm−3), only the cyclohexane-phase phosphorescence was observed at 77 K; the lower energy components of the well-known doublet band series in the cyclohexanephase phosphorescence were found to decrease in intensity relative to the higher energy components, with increasing concentration of halomethane. When the halomethane concentration was raised to a range higher than 10−1 mol dm−3, where the complex formation between pyrazine and the halomethanes was confirmed through absorption spectroscopy, new phosphorescence bands appeared in the 373–375 nm region for all the systems studied. With further increase of the halomethane concentration, the new bands decreased in intensity or disappeared, and the phosphorescence approached to those in the pure halomethanes. Comparison of the absorption and phosphorescence excitation spectra shows that the new phosphorescence bands result from the 1 : 1 pyrazine–halomethane complexes. The possibility of hydrogen-bonding species formation with chloroform and dichloromethane has been discussed in the light of the phosphorescence spectra studied in the ethanol–cyclohexane mixed solvents.
The trans-cis Isomerization of Potassium Diaquabis(oxalato)chromate(III) in Various Organic Solvent–Water Mixtures
Authors: Uchida Kengo , Takinami Yoshinobu
Published: July 2006

Kinetics of the trans-cis isomerization of K[Cr(ox)2(H2O)2] have been investigated in binary mixed solvents, including ethanol–, dioxane–, and acetone–water mixtures. The first-order rate constant decreases with an increase in the concentration of an organic solvent. A similar decrease by the addition of an organic solvent was observed in the presence of univalent and bivalent cations. These results are in contrast to those for the analogous malonato complex, and suggest that both dissociation and twist mechanisms are involved in the reaction.
Solubility Isotherms of Systems Containing Optically Active Tris(ethylenediamine)cobalt(III) Ion. II. Reciprocal Salt-pairs, (Λ-[Co(en)3]3+, Δ-[Co(en)3]3+)–(I−, (R,R)-C4H4O62−), at 25 °C
Authors: Fuyuhiro Akira , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

A four-component solubility isotherm consisting of Λ-[Co(en)3]3+, Δ-[Co(en)3]3+)–(I−, (R,R)-C4H4O62−)–H2O was determined at 25 °C. It was found that four double salts rac-[Co(en)3]I3·H2O, Λ-[Co(en)3]I(d-C4H4O6)·2H2O, Λ-[Co(en)3]0.48·Δ-[Co(en)3]0.52(d-C4H4O6)1.5·5H2O, and Δ-[Co(en)3]I(d-C4H4O6)·nH2O exist, six invariant points appearing. Application of this phase diagram to practical optical resolution is discussed in comparison with a system containing Br−. Some models of phase diagram for effective optical resolution in reciprocal salt-pairs are proposed.
The Initial Sintering of Alkaline Earth Oxides in Water Vapor and Hydrogen Gas
Authors: Ito Tomoyasu , Fujita Masato , Watanabe Masahiro , Tokuda Taneki
Published: July 2006

The initial sintering (crystallite growth and surface-area diminution) of freely dispersed powders was studied. For MgO in H2O vapor, the sintering rate at 1073 K was directly proportional to the water-vapor pressure, PH2O, in the range of 27–2700 Pa, and the apparent activation energy, E, for the sintering was 137 kJ mol−1. These facts lead to the conclusion that, in this system, the surface migration of O2− caused by the repetition of the adsorp-tion-desorption cycle of the H2O molecule is rate-determining step for the sintering. For CaO in H2O vapor, the rate-determining step appears to be migration on and/or near the surface of a cation vacancy produced by the H2O adsorption, judging upon the facts that the sintering rate at 873 K was proportional to PH2O0.34 in the range of 11–1600 Pa and that E was 79.4 kJ mol−1. For MgO in H2 gas, the sintering rate at 1123 K was approximately proportional to the hydrogen pressure in the range of 3.3–66.5 kPa and E was 310 kJ mol−1, indicating that the sintering in H2 was caused by H2O vapor formed upon the desorption of the surface hydroxyl groups which had been produced by a heterolytic dissociative adsorption of H2.
Molecular Conformations of 4-Aminomethyl-1-cyclohexanecarboxylic Acids in Aqueous Solution
Authors: Yanaka Mikirô , Enomoto Satoru , Inoue Yoshio , Chûjô Riichirô
Published: July 2006

The structures of cis- and trans-4-aminomethyl-1 -cyclohexanecarboxylic acids were studied by proton and carbon-13 NMR, and by semiempirical molecular orbital methods (CNDO/2 and MNDO). Both isomers exist in zwitter ionic forms in aqueous solution. It was found that the most stable conformations for them are all staggered forms: the diequatorial conformer in the trans form and the axial carboxyl group in the cis form. These preferred conformers are similar to those in crystalline states. In these conformers the deformation is very small in the cyclohexane ring of the trans form. The atomic distance between the nitrogen of amino group and the carbon of carboxyl group in the preferred conformer of trans form is 0.65 nm and that in cis form is 0.55 nm. This distance of 0.65 nm will play an important role in the antifibrinolytic effect.
Liquid Crystal Formation in Binary Systems. III. Effect of the Central Double Bond Linkage on the Induction of Nematic Liquid Crystals
Authors: Araya Kotaro , Matsunaga Yoshio
Published: July 2006

The effect of central double bond linkage on the induction of liquid crystals has been examined employing eight binary mixtures of potentially mesomorphic electron donors and acceptors of the type 4-X–C6H4–Z–C6H4–OC2H5-4. The central linkage Z is –N=N–, –CH=N–, or –CH=CH– group. The terminal substituent X is a dimethylamino group in the donor compounds and a nitro group in the acceptor compounds. A stable nematic liquid crystal is observable with the systems of azo-azo and azo-azomethine compounds. When the acceptor is the nitro derivative of stilbene, a 2 : 3 molecular complex is formed and no liquid crystal can be found, irrespective of whether the partner is an azo or azomethine compound. The latent induction of nematic liquid crystals in these combinations has been proved by studies on the phase diagrams of the pseudo-binary systems with a reference nematogen, azoxy-dianisole. The nematic liquid crystal-isotropic liquid transition temperatures of both the component compounds and the equimolar mixtures depend on the central double bond linkage: the order is –CH=CH–>–N=N–>–CH=N–. On the other hand, the order of –N=N– and –CH=N– groups is reversed in the extent of the induction of nematic liquid crystals.
UV Absorption Studies of the Pyrolysis of Butane in Shock Waves
Authors: Koike Tohru , Morinaga Kihei
Published: July 2006

The UV absorption measurements at 216 nm were carried out for three shock-heated mixtures, 1, 2, and 2 8% n-C4H10 diluted in Ar, in the temperature range of 1290–1610 K and at about half atmospheric pressures. From the initial absorption rise, which can be attributed to the CH3 growth, the rate constant of the reaction, n-C4H10=CH3+n-C3H7, was evaluated as k2=8.9×1013exp (−71.9 kcal⁄RT) (s−1). A computer modeling using a 44-reaction mechanism including the k2 value so evaluated could reproduce the absorption early in the reaction and in the temperature range of 1420–1610 K with a reasonable value.
Highly Active Aluminas far Isomerization of 1-Butene and Hydrogen Exchanges between Ethylene or Cyclopropane and Deuterium
Authors: Utiyama Masahiro , Hattori Hideshi , Tanabe Kozo
Published: July 2006

Among eleven kinds of aluminas, alumina V prepared from aluminium sulfate with urea exhibited a pronounced activity for the isomerization of 1-butene, while alumina III or II prepared from aluminium nitrate with ammonia or urea showed the highest activities for the exchange reactions between ethylene or cyclopropane and deuterium, respectively.
Ozonization of Organic Compounds. V. Aromatic Compounds
Authors: Saito Tsuneo , Niki Etsuo , Kamiya Yoshio
Published: July 2006

The ozonization of several aromatic compounds has been carried out at 30 °C in carbon tetrachloride. It was found that three processes proceeded simultaneously; that is, normal and anomalous ozonolyses to give respectively α,β-dicarbonyl and carboxylic compounds and polymerization. Carboxylic acids were the major products. Benzene and hexamethylbenzene gave formic acid and acetic acid respectively, while toluene and 1,3,5-trimethylbenzene gave mixtures of these acids. As the ozonization proceeded, white gummy polymers precipitated, the molecular weight ranged from several hundreds to a few thousands. They contained high concentrations of oxygen which was incorporated into polymer as carbonyl, carboxylic acid, peroxide and/or ether. The polymers were thermally stable below 150 °C.
A Convenient Synthesis of Azuleno[2,1-b]thiophene
Authors: Yamane Kameji , Fujimori Kunihide , Takeuchi Toru
Published: July 2006

Azuleno [2,1-b]thiophene and its derivatives were prepared from ethyl 2-chloro-3-formylazulene-1-carboxylate and ethyl mercaptoacetate in a few steps.
Properties of Poly electrolyte Complexes Consisting of [2-(Diethylamino)ethyl]dextran Hydrochloride, Carboxymethyldextran, and Sodium Dextran Sulfate for Clot Formation in Vitro
Authors: Kikuchi Yasuo , Shimizu Koji
Published: July 2006

A polyelectrolyte complex (PEC) prepared at higher hydrogen ion concentration enhanced the coagulation of blood, whereas PEC prepared at lower hydrogen ion concentration prevented coagulation of blood. This difference sholud be attributed to the difference in the molecular structures of the PEC prepared.
Stabilization of Normal Methyl Radicals after γ-Radiolysis at 300 K
Authors: Oduwole Duro A , Wiseall Barrie
Published: July 2006

Radiolytically produced normal methyl radicals are stabilized on solid surfaces at room temperature for the first time. The remarkable stability of this species on basic and neutral alumina surfaces at 300 K and in the presence of oxygen makes this system potentially useful as an intermediate in organic synthesis.
Reaction between Aluminium Trichloride and Steam in the Vapor Phase and Properties of the Aluminium Oxide Formed
Authors: Shoji Yuichi , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction between gaseous AlCl3 and steam, and the products formed were examined by X-ray analysis, TG, DTA, and electron microscopy. The thermal transitions of the Al2O3 formed under various conditions were also examined. The reaction between gaseous AlCl3 and steam occurs even at 150 °C and proceeds rapidly above about 400 °C. The product is amorphous Al2O3 below 600 °C, amorphous Al2O3 containing poorly crystallized γ-Al2O3 at 800 °C, γ-Al2O3 containing amorphous Al2O3 at 900 °C, and γ-Al2O3 at 1000 °C. Also, it was observed that the Al2O3 formed below 900 °C included a chloride oxide of aluminium, which decomposed in the vicinity of 830 °C to form γ-Al2O3 with the evolution of gaseous AlCl3. On heating the amorphous Al2O3 formed by the reaction between gaseous AlCl3 and steam, the transition: amorphous \xrightarrowca.700°C χ \xrightarrowca.800°C κ \xrightarrowca.1000°C α occurs; and on heating the γ-Al2O3 formed by the same reaction, the transition: γ \xrightarrowca.900°C δ \xrightarrowca.1000°C θ \xrightarrowca.700°C α occurs.
Dealkylation Reaction of Acetals, Phosphonate, and Phosphate Esters with Chlorotrimethylsilane/Metal Halide Reagent in Acetonitrile, and Its Application to the Synthesis of Phosphonic Acids and Vinyl Phosphates
Authors: Morita Tsuyoshi , Okamoto Yoshiki , Sakurai Hiroshi
Published: July 2006

A mild and efficient method has been developed for carbon-oxygen bond cleavage using chlorotrimethylsilane/sodium iodide in acetonitrile. It was applied to synthetic transformation under nonaqueous and neutral conditions, such as acetal deprotection and the synthesis of phosphonic acids from the corresponding dialkyl phosphonates via methanolysis of their silyl esters. Effectiveness of various kinds of metal or ammonium iodides for this type of dealkylation was examined in the acetonitrile solution by 1H NMR. Satisfactory results were also obtained with lithium or potassium iodide in place of sodium iodide. However, copper(I) or quarternary ammonium iodide was ineffective. Chlorotrimethylsilane/lithium bromide in acetonitrile is effective for selective dealkylation of multifunctional phosphonic esters or dialkyl vinyl phosphates.
Reaction of Organic Sulfur Compounds with Hyperoxide Anion (O2\ewdot). IV. Evidence for Formation of Peroxysulfur Intermediates: Oxidation of Sulfoxides, Phosphines, and Olefins with Intermediary Peroxysulfur Species
Authors: Oae Shigeru , Takata Toshikazu , Kim Yong Hae
Published: July 2006

Formations of peroxy-sulfenate(I), -sulfinate(II), and -sulfonate(III) as intermediates have been confirmed by stripping the peroxy oxygen with three kinds of trapping agents such as sulfoxides, phosphines, and olefins, added in the reaction systems of various organic sulfur compounds with hyperoxide anion (O2\ewdot). These sulfoxides, phosphines, and olefins were inert to O2\ewdot alone while electrophilic olefins, such as α,β-unsaturated ketones reacted readily with O2\ewdot to afford the carboxylic acid. Sulfoxides, added into the reaction system of disulfide, thiosulfinic S-ester, thiosulfonic S-ester, or sulfonyl chloride with O2\ewdot, were found to be oxidized to the sulfones with peroxysulfur intermediates formed in situ in the system. Phosphines, added into the reaction system of disuflide or sodium thiolate with O2\ewdot were also oxidized to the phosphine oxides. Not only stilbene and acenaphthylene but also chalcone and its derivatives, placed in the reactions of sulfonyl chloride, sulfinyl chloride and thiosulfonic S-ester with O2\ewdot were found to be oxidized to the corresponding epoxides. These observations suggest clearly that the intermediary peroxysulfur compounds can act as oxidizing agents which oxidize these trapping agents by the nucleophilic oxygenative oxidation. Similar intermediates were postulated and confirmed in the alkaline autoxidations of thiol and disulfide in which added phosphines and sulfoxides were also found to be oxidized to their oxides. The mechanisms of the reactions of these trapping agents with peroxysulfur intermediates are discussed.
Synthesis of 7-Alkylidene-5-oxadispiro[2.0.4.4]dodecan-6-ones
Authors: Kakiuchi Kiyomi , Yonei Takehito , Tobe Yoshito , Odaira Yoshinobu
Published: July 2006

7-Alkylidene-5-oxadispiro[2.0.4.4]dodecan-6-ones, having a cyclopropane ring, were synthesized by the α-alkylidenation of easily available 5-oxadispiro[2.0.4.4]dodecan-6-one. Also, α-alkylidene-γ-butyrolactones, containing an additional hydroxyl group, were prepared. The screening of the biological activities of these γ-lactones gave the interesting results. For instance, α-isopropylidene-γ-lactone exhibited the antiarrhythmia activity in vivo.
A Photoelectrochemical Study of Polyacetylene, (CH)x
Authors: Yamase Toshihiro , Harada Hideo , Ikawa Tsuneo , Ikeda Sakuji , Shirakawa Hideki
Published: July 2006

The photoelectrochemical behavior of p-type semiconducting trans-(CH)x film in the presence of N,N′-dimethyl-4,4′-bipyridinium as the solution species is described. The spectral response of the photocurrent shows a mismatch with the absorption spectrum, and the quantum yield (≈10−3) of the charge flow is extremely low. It is assumed that (CH)x film has a high trap density and that the lifetime of the photogenerated hole is limited by trapping and recombination in the space-charge region.
Prediction of Adsorption Isotherms of Organic Compounds from Water on Activated Carbons
Authors: Abe Ikuo , Hayashi Katsumi , Kitagawa Mutsuo
Published: July 2006

An adsorption equation is postulated for predicting the adsorption isotherms of organic compounds from water on activated carbons.
The Measurement of the Distribution Equilibrium Constant of Metallic Mercury for Hg(aq)\ightleftharpoonsHg(gas)
Authors: Okouchi Shoichi , Sasaki Sokichi
Published: July 2006

The gas-aqueous distribution equilibrium constant of mercury(0) was determined in the temperature range from 5 to 45 °C. The experiment was made by volatilizing metallic mercury dissolved in water to the gas phase, which was connected with the absorption cell in a cold-vapor atomic absorption spectrophotometer, and by measuring the absorbance under gas-aqueous distribution equilibrium conditions. The distribution equilibrium constant, [Hg]gas/[Hg]aq, was found, e.g., to be 0.40±0.02 at 25 °C. The effect of the concentration of NaCl on the distribution equilibrium constant was measured at 25 °C. The salting-out effect was found to be expressed by the Setschenow equation, and the salting-out coefficient was found to be 0.105.
Reaction of μ-Peroxo Complexes of Palladium with Alcohols, Amines, and Thiols
Authors: Sugimoto Ryuichi , Eikawa Hajime , Suzuki Hiroharu , Moro-oka Yoshihiko , Ikawa Tsuneo
Published: July 2006

Reactions of μ-peroxo complexes of palladium with alcohols, amines, and thiols proceed at room temperature to afford hydrogen peroxide and alkoxo-, amido-, and alkylthio-bridged complexes of palladium, respectively.
Cyclodehydrogenation of 3-Cinnamoyltropolones with 2,3-Dichloro-5,6-dicyanobenzoquinone
Authors: Imafuku Kimiaki , Yamaguchi Kazuko
Published: July 2006

3-Cinnamoyltropolone and 3-(3-methoxycinnamoyl)tropolone were oxidized with 2,3-dichloro-5,6-dicyanobenzoquinone to give 2-phenyl- and 2-(3-methoxyphenyl)-4,9-dihydrocyclohepta[b]pyran-4,9-diones, while 2′-and/or 4′-methoxy-substituted 3-cinnamoyltropolones gave 2-arylmethylene-2H-3,8-dihydrocyclohepta[b]furan-3,8-diones.
Temperature Dependence of the Rate Constants of H and D-Atom Additions to C2H4, C2H3D, C2D4, C2H2, and C2D2
Authors: Sugawara Ko-ichi , Okazaki Kiyoshi , Sato Shin
Published: July 2006

The high pressure limiting rate constants of H and D-atom additions to C2H4, C2H3D, C2D4, C2H2, and C2D2 have been measured in the temperature range from 206 to 461 K by means of the pulse radiolysis-resonance absorption method. Practically no isotope effects due to the deuteration of ethylene and acetylene could be observed. The rate constants were compared with those calculated by the activated complex theory using the potential energy surfaces provided by the ab initio calculations. Concerning the isotope effects, very poor agreement was obtained between theory and experiment. This seems to suggest that the assumptions on which the activated complex theory is based have to be reconsidered when it is applied to such reactions as H+C2H4→C2H5 and H+C2H2→C2H3.
Spherical Particles and Their Surface Properties. III. Formation of Spherical Particles of Metal Oxides by O2–H2 Flame Fusion
Authors: Kittaka Shigeharu , Morimoto Tetsuo
Published: July 2006

The formation mechanism of spherical particles of various metal oxides through O2–H2 flame fusion was investigated. Molten droplets of Al2O3 are solidified to form spherical particles having the structure of δ- and θ-Al2O3 in the surface layer and α-Al2O3 inside. Heat treatment of the spherical particles of Al2O3 at temperatures higher than 1573 K gave rise to the transition from δ- and θ-Al2O3 to α-Al2O3 and made the crystal growth, but no change in the smooth surface structure was observed, contrary to the case of TiO2 where facetting of the surface occurred on heating. In the cases of NiO and Cr2O3, particles bigger than 2–3 μm in diameter are spherical, but smaller ones are apt to form single crystals. With ZnO, SnO2, and MgO, no spherical particles were formed. It is suggested that amorphous or polymorphous substances easily form spherical particles but monomorphous ones do not. Substances, which can sublime or have higher melting point, do not give pherical particles but only single crystals.
Amination of Chloromethylated Polystyrene with Amino Alcohols
Authors: Kawabe Hiroshi
Published: July 2006

The amination of chloromethylated polystyrene (CMPS) and benzyl chloride (BC) with amino alcohols was investigated kinetically in dioxane, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). The amination rate was related mainly to the branching structure and partly to the pK of amino alcohols; ΔG\eweq and ΔH\eweq increased in the following order: 2-aminobutanol<1-amino-2-propanol<2-amino-1-butanol<2-amino-2-methyl-1-propanol<tris(hydroxymethyl)methanamineDMF>DMSO. The difference in the amination rate between CMPS and BC is also discussed in terms of the activation parameters. The amination rate of the polymer partly containing quaternary ammonium groups (QCMPS) in DMSO was found to be greater than that of CMPS probably owing to the ion-dipole interaction.
Effect of Pressure on Charge-transfer Spectra and Equilibria in Solutions of Tetracyanoethylene and Styrene Derivatives
Authors: Uosaki Yasuhiro , Nakahara Masaru , Sasaki Muneo , Osugi Jiro
Published: July 2006

Charge-transfer spectra of trans-stilbene–, cis-stilbene–, 1,1-diphenylethylene–, and α-methylstyrene–TCNE mixtures in chloroform and in 1,2-dichloroethane have been measured at high pressures at 25 °C. The spectra shifted to a lower energy (red shift) with increasing pressure, the two bands in each complex shifting almost in parallel to each other. The shifts are qualitatively interpreted by McRae’s theory. The spectral changes in intensity with pressure was analyzed taking account of reversible formation of the EDA complex and 1,4-cycloadduct; only the complex was formed in the stilbene systems. Volume changes for the complex formation are in the range of −4 to −7 cm3 mol−1 and those for the cycloaddtion are in the range of −23 to −30 cm3 mol−1. The latter slightly increase in magnitude when solvent is changed from chloroform to a more polar solvent, 1,2-dichloroethane.
Tetrahedral Transition Metal Complexes of [MW12O40]-type (M=CuII, FeIII, CoII) with Dodecatungstate as Tetrahedral Ligand
Authors: Nomiya Kenji , Miwa Makoto , Kobayashi Ryoichi , Aiso Masahiro
Published: July 2006

Tetrabutylammonium salts of 12-heteropolytungstates with central transition metal ions in a tetrahedral oxygen environment, MW12O40 (M=CuII, FeIII, CoII), have been prepared and their spectroscopic data (infrared (IR), near-infrared, UV-vis, and magnetic circular dichroism (MCD)) presented.
Synthesis of o-(2-Indolyl)benzoic Acids from Indole
Authors: Itahara Toshio
Published: July 2006

Treatment of 6H-isoindolo[2,1-a]indol-6-ones with potassium t-butoxide/t-butyl alcohol containing a small amount of water at 82°C afforded o-(2-indolyl)benzoic acids in good yields.
A Synthesis of Human Proinsulin C-Peptide
Authors: Igano Ken’ichi , Minotani Yuriko , Yoshida Nobuo , Kono Masao , Inouye Ken
Published: July 2006

A peptide corresponding to the thirty-one amino acid sequence of human proinsulin C-peptide (positions 33–63 of proinsulin) was synthesized by the solid-phase method. The product was purified consecutively by gel filtration, DEAE-cellulose chromatography, and high-performance liquid chromatography (HPLC). The purified material behaved as a single component in reversed-phase HPLC, gave correct amino acid ratios, and was not distinguished from natural human C-peptide in terms of immunoreactivity and chromatographic behaviors. The α→β transpeptidation at the Asp-Leu sequence, possible to occur associated with the HF cleavage, was studied using model peptides to demonstrate that the formation of β-peptide was 3–4% regardless of whether the β-carboxylic acid is free or protected as a benzyl ester.
Adsorption Behavior of N-Containing Heterocycles at a Mercury/Water Interface
Authors: Ikeda Osamu , Goto Fumio , Tamura Hideo
Published: July 2006

Adsorption behavior of 1-methylimidazole and 1-methylbenzimidazole at a mercury/water interface were investigated by electrocapillary measurement. These heterocycles showed a horizontal orientation at lower surface excesses, but at higher surface excesses a vertical one complicated by the presence of the horizontal one. In positive surface charge density, 1-methylbenzimidazole showed an anomalous behavior in which the potential drops across the inner layer, Δ2Mφ does not change with adsorption through the displacement of the water molecules on the electrode. The analysis of the electrosorption valency indicated the absence of a partial charge transfer between the electrode and the adsorbate. This anomalous behavior was interpreted by the compensation effect between the polarization of the water molecules due to the permanent dipoles and that of the 1-methylbenzimidazole molecules due to the dipoles induced in the electric field.
The Electronic Spectra of Psoralens in Their Ground and Triplet Excited States
Authors: Song Pill-Soon , Shim Sang Chul , Mantulin William W
Published: July 2006

The first absorption band in psoralens arises from the coumarin moiety, and its location, intensity and polarization are strongly dependent on 5- and 8-substitution. The first two absorption bands in psoralen, angelicin, and methylpsoralens are polarized nearly parallel (angle between them Δθ≤20°), while methoxypsoralens display wider polarization angles.
Mössbauer Study of Solid State Photolysis of Alkali Tris(oxalato)ferrates(III)
Authors: Brar Ajaib Singh , Randhawa Balwinder Singh
Published: July 2006

Solid state photolysis of alkali tris(oxalato)ferrates(III) (Li, Na, K, Cs, and NH4) was studied with mercury radiation in the visible region by means of Mössbauer spectroscopy. The intermediate K6[Fe211(ox)5] is formed in the case of potassium tris(oxalato)ferrate (III) and FeC2O4·2H2O in the case of other alkali tris(oxalato)ferrates(III) [Li, Na, Cs, and NH4].
Studies in the Molten State, Viscosities of trans-Stilbene, N-Benzylideneaniline, and N-Benzylidene-p-toluidine Melts Near Their Melting Temperatures
Authors: Kwatra Bimla , Ramakrishna Venketachari , Suri Sushil Krishan
Published: July 2006

The viscosities and densities of trans-stilbene, N-benzylideneaniline (BA) and N-benzylidene-p-toluidene (BT) melts at various temperatures near their respective melting temperatures have been determined. In all the cases, a precursor behaviour in crystal phase at temperatures below the melting temperature has been observed. The viscosity vs. temperature relationships have been discussed in two parts: one in the liquid state and the other in the supercooled region. The values of energy and entropy of viscous flow are indicative of molecular association in BA and BT. The enhanced viscosity in the supercooled region has been attributed to the cluster formation. The hinderance to molecular rotation, as a factor influencing viscosity can not be ruled out.
Optical Determination of Pair Correlation in π-Electron System
Authors: Basu Sadhan
Published: July 2006

α, p, and β bands in the electronic spectra of polynuclear aromatic hydrocarbons have been found to converge to a limiting value. This has been ascribed to pair correlation effect arising from interaction of π-electrons with σ-framework and with molecular vibrations of appropriate symmetry.
Flavonoids of Polygonum sieboldi and P. filiforme
Authors: Isobe Takahiko , Kanazawa Keiji , Fujimura Makoto , Noda Yukinao
Published: July 2006

Five flavonoids containing a new flavonol glycoside were isolated from Polygonum  sieboldi and P. filiforme. The structure of the new compound was determined as quercetin 3-rhamnoside 2″-gallate by chemical and spectroscopic data.
Nature of Acid Sites on TiO2, and Their Reactions with OH and NH2 Groups of 3-Amino-1-propanol, 1-Propanol, and 1-Propylamine
Authors: Kantoh Toshinori , Okazaki Susumu
Published: July 2006

The IR spectra for pyridine adsorbed on the surfaces of TiO2 (SA) (anatase type), prepared from titanium tetraisopropoxide, showed the existence of only Lewis acid sites which were not converted to the Br\ddotonsted type by the addition of water. However, TiO2 (SB) (anatase type), prepared by the hydrolysis of titanium oxide sulfate, showed both Lewis and Br\ddotonsted acidities. The Lewis acidity of SB was converted to the Br\ddotonsted type by the introduction of water vapor. The 3-amino-1-propanol compound interacted with both Lewis and Br\ddotonsted acid sites on the TiO2 surfaces in a manner similar to propylamine rather than to 1-propanol. However, in the case of SA, interactions between OH groups of the amino alcohol and surface OH groups seemed to take place to some extent. The mode of the surface reaction of TiO2 differes markedly from that of SiO2 which has no surface acidity. A linear relationship between the amount of surface OH groups on SB and the amount of the reaction of 3-amino-1-propanol at 235 °C in an autoclave was observed. The formation of oriented and closely packed layers of adsorbed molecules was observed for all the combination of SB and 3-amino-1-propanol, in which some condensation (mainly dimerization) seemed to be promoted by acid sites on SB.
The Crystal Structure of N-Methylviologenium 2-Dicyanomethylene-1,1,3,3-tetracyanopropanediide, [(CH3·NC5H4·C5H4N·CH3)2+·(C10N6)2−]
Authors: Nakamura Kenichi , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

[(CH3·NC5H4·C5H4N·CH3)2+·(C10N6)2−] crystallizes in the space group of P21⁄c, with four formula units. The unit-cell dimensions are; a=14.625(2), b=8.361(2), c=17.332(3) Å, and β=107.51(2)°. The crystal structure was established by means of the symbolic addition method. For 2767 non-zero reflections, R is 0.074. In the crystal, divalent cations and divalent anions are stacked alternately to form infinite columns which are parallel to the b axis. Short atomic contacts are mostly involved between nitrogen atoms of the anion and carbon atoms of the cation. The (C10N6)2− anion takes a three-bladed propeller shape; however, it has no symmetry, unlike those in hexahydrated calcium and quinolinium salts. In the [(CH3·NC5H4·C5H4N·CH3)2+] cation, two pyridine rings are twisted about the central C–C bond; the dihedral angle between the planes of two rings is 19.6(2)°.
Vibrational Spectra and Normal Coordinate Calculations for Trimethylgermane
Authors: Imai Yoshika , Aida Koyo
Published: July 2006

Vibrational spectra of (CH3)3GeH, (CH3)3GeD, (CD3)3GeH, and (CD3)3GeD were obtained. Assignments for all the fundamentals except internal torsions were made by assuming the C3V molecular symmetry. Normal coordinate calculations were carried out to confirm the assignments.
High-performance Liquid Chromatographic Determination of Organic Substances by Metal Chelate Derivatization. I. Dithiocarbamate Chelates of Aliphatic Amines
Authors: Moriyasu Masataka , Hashimoto Yohei , Endo Masaru
Published: July 2006

The use of the conversion of aliphatic primary and secondary amines into metal dithiocarbamate chelates was examined for high-performance liquid chromatographic determination of these amines. Characteristic chromatogram patterns based on the difference in the rate of ligand exchange were obtained for different central metal ions. When Hg(II) chelates were tested, trace determination of individual secondary amines was possible because only the peaks of binary complexes corresponding to each amine appeared on chromatograms. When Ni(II) and Pd(II) chelates were tested, peaks to ternary complexes as well as those of binary complexes appeared on chromatograms. This phenomenon was applied to the determination of optical purity of optically active amines. A description is given of applications to microdetermination of antiasthmatic ephedrine isomers, to determination of their optical purity in Chinese crude drugs, and to their preparation.
Mass-spectrometric Measurement of Activities in Both Solid and Liquid Solutions of the KCl–NaCl System
Authors: Itoh Mitsuru , Sasamoto Tadashi , Sata Toshiyuki
Published: July 2006

The activities of the KCl–NaCl system were mass-spectrometrically determined by the ion-current-ratio method in the temperature range From 793 to 1083 K. As a result, the activities of KCl or NaCl in the solid solution showed greatly positive deviations from Raoult’s law while the liquid solution at 1083 K gave slightly negative values. The heats of mixing in the solid solution were calculated from the temperature dependence of the modified ion-current ratios, [(INa2Cl+/XNaCl2)/(IK2Cl2/XKCl2)]. The excess entropy of mixing in the solid solution was attributed to the change in the vibrational spectrum, and the vibrational contribution to the heat of mixing was evaluated.
Catalytic Activity of V–Sn Oxides for Oxidation Reactions
Authors: Ono Takehiko , Nakagawa Yoshiro , Kubokawa Yutaka
Published: July 2006

The rate of oxidation of C3H6, C2H4, C3H8, and CO has been investigated over V–Sn oxides of various compositions. The rate shows two maxima at V–Sn(V/Sn=2/1) and (1/8) oxides. Comparison between the rate of reduction of the oxides with C3H6 and that of the corresponding catalytic oxidation suggests that the oxygen species responsible for oxidation differs for V–Sn(2/1) and V–Sn(1/8) oxides. The amount of oxygen desorbed in the temperature range 400–530 °C varies with the composition of the V–Sn oxides, showing a maximum at V–Sn(2/1) oxide. With V–Sn(1/8) oxide, little or no oxygen desorption is observed. On the basis of these results together with those of structural studies, it is concluded that the rate maximum with V–Sn(2/1) oxide arises from formation of an amorphous material from which lattice oxygen is easily released, while the rate maximum with V–Sn(1/8) oxide is associated with the presence of V4+ ions dissolved in SnO2.
Photoreaction of N,N′-Dibromo-2,5-piperazinedione
Authors: Sera Akira , Itoh Kuniaki , Yamada Hiroshi , Aoki Ryuichi
Published: July 2006

The photolysis of N,N′-dibromo-2,5-piperazinedione in dichloromethane gave an unstable photoproduct. The alcoholysis of the photoproduct in the presence of a small amount of hydrogen bromide yielded 3,6-diethoxy-2,5-piperazinedione and its alcoholyzed products, ethyl diethoxyacetate, ethyl 2-(diethoxyacetylamino)-2-ethoxyacetate, N-(1-ethoxy-1-ethoxycarbonylmethyl)oxamide, and ethyl N-(diethoxyacetyl)glycinate. The reactions of the photoproduct with other nucleophiles also gave the corresponding substituted 2,5-piperazinediones. The structure of the primary photoproduct was deduced to be 3,6-dibromo-2,5-piperazinedione on the basis of these observations.
Branched-chain Sugars. XXIII. Stereoselectivities in the Addition of Nucleophiles to Several 4-Uloses
Authors: Matsuzawa Masafumi , Sato Ken-ichi , Yasumori Toshio , Yoshimura Juji
Published: July 2006

The stereoselectivities in the 1,2-addition of nucleophiles such as methylmagnesium iodide, vinylmagnesium bromide, and 2-lithio-2-methyl-1,3-dithiane to seven kinds of 4-uloses were examined. The configurations of C-vinyl derivatives obtained were determined from the chemical shifts of α-carbons in 13C-NMR spectra.
Oxidation of Olefins into α-Phenylseleno Carbonyl Compounds. Highly Regioselective anti-Markownikoff Type Oxidation of Allylic Alcohol Derivatives
Authors: Shimizu Makoto , Takeda Ryo , Kuwajima Isao
Published: July 2006

By using (C6H5Se)2–t-BuOOH or (C6H5Se)2–(C6H5SeO)2O system, oxoselenenylation reactions of C=C bonds have been examined with allylic and homoallylic alcohol derivatives, and substituted cyclohexenes, and allyl t-butyldimethylsilyl ethers are found to undergo regioselective conversion into β-siloxy α-phenylseleno carbonyl compounds in high yields.
Absolute Intensity Measurement of the ν4 Band of Fluoroform by the Use of a Tunable Diode-laser Source
Authors: Sofue Susumu , Kawagughi Kentarou , Hirota Eizi , Fujiyama Tsunetake
Published: July 2006

The absolute infrared absorption intensities have been measured for the P35(35) and P36(36) lines, which belong to the ν4 fundamental of fluoroform, by the use of a tunable diode-laser source. The observed intensity, Γ, was 5360+220 cm2 mol−1. This intensity value was compared with that observed by the conventional method.
Effects of Intermolecular Hydrogen-bonding on the Luminescence Properties of Acetophenone, Characterization of Emission States
Authors: Ghoshal Suniti Kumar , Sarkar Susil Kumar , Kastha Gouranga Sundar
Published: July 2006

The effects of intermolecular hydrogen-bond formation by protic solvents on the absorption and luminescence properties of acetophenone have been investigated. It has been concluded from analysis of the T←S0 absorption, phosphorescence excitation spectra and the emission characteristics that the lowest triplet state of acetophenone in its vapor phase and in nonpolar as well as in moderately polar solvents (e.g., ethanol, EPA etc.) is of n-π* character. In rigid polar media, acetophenone exhibits a very weak 1π-π*→S0 fluorescence and a weak 3π-π*→S0 phosphorescence superposed with the principal 3π-π*→S0 emission. A progressive enhancement of both of these emissions with increasing polarity of the solvent has been observed. It is shown that the fluorescence and the dual phosphorescence emissions from acetophenone in rigid polar media arise as a result of decreased efficiencies of the spin-orbit and vibronic coupling interactions due to intermolecular hydrogen-bond formation by the protic solvents.
Oxidation of Copper in Nitrogen Dioxide
Authors: Takasu Yoshio , Tomo-oka Teruhide , Matsuda Yoshiharu
Published: July 2006

Thermal microgravimetry, mass spectrometry, and X-ray diffractometry were used to investigate the ability of NO2 to oxidize copper. NO2 oxidizes a copper plate with formation of oxide film consisting of Cu2O (predominant) and CuO. The oxidation obeys a cubic law, and proceeds faster than in oxygen. An oxidation mechanism is presented on the basis of kinetic and structural data.
Stereochemistry of Friedel-Crafts Alkylation of Benzene with Optically Active 2-Chlorobutane
Authors: Suga Sohei , Segi Masahito , Kitano Kiyoyuki , Masuda Shinji , Nakajima Tadashi
Published: July 2006

The alkylation of benzene with (+)-2-chlorobutane (1) by Lewis acid catalyst gave stereospecifically (−)-2-phenylbutane (2) with inversion of configuration at low temperature for short reaction times. A lowering of the stereospecificity of the reaction was found to be partly due to the racemization of (+)-1 and (−)-2.
Fused Heterocycles. IV. Synthesis of 7-(o-Hydroxyphenyl)-3,5-dimethyl-7,8-dihydro-6H-isoxazolo[4,5-b]azepines
Authors: Malla Reddi Kooturu , Janakirama Rao Citineni , Krishna Murthy Ananthula
Published: July 2006

Michael addition of acetylacetone to 3-methyl-4-nitro-5-(o-hydroxystyryl)isoxazoles gives 4-(o-acetoxyphenyl)-5-(3-methyl-4-nitro-5-isoxazolyl)-2-pentanones (4). Reductive cyclization of 4 with tin(II) chloride and concentrated hydrochloric acid leads to 7-(o-hydroxyphenyl)-3,5-dimethyl-7,8-dihydro-6H-isoxazolo[4,5-b]azepines. The formation of 4 has been rationalized through ortho effect. NMR and mass spectra of products have been discussed.
The Precursors of Phenols Produced in the γ-Radiolysis of Aromatic Hydrocarbons in Liquid Carbon Dioxide
Authors: Karasawa Hidetoshi , Yugeta Rei , Yamaguchi Akira , Sato Shin
Published: July 2006

The γ-ray-induced oxidation of toluene in liquid carbon dioxide has been reinvestigated. In order to discuss the precursors of the main products: three kinds of cresols and benzyl alcohol, 1-butene was used as the scavenger of oxygen atoms. The formation of cresols and benzyl alcohol was well explained by the participation of two precursors: one is oxygen atoms and the other is ionic species, O− or/and CO3− ions. The ratio of the G-value of oxygen atoms to that of the sum of O− and CO3− ions initially formed was estimated to be 4 : 1 for pure liquid carbon dioxide. The spur model previously proposed was applied to explain the formation of O− and CO3− ions.
The Molecular Structures of Thiomethoxymethylbis(triphenylphosphine)-palladium Hexafluorophosphate and Perchlorate at −160 °C
Authors: Miki Kunio , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The molecular structures of [Pd(CH2SCH3)(PPh3)2]PF6(3a) and [Pd(CH2SCH3)(PPh3)2]ClO4(3B) at −160°C were determined by means of X-ray diffraction. Crystals of both complexes belong to the monoclinic system: 3a, a=11.535(2), b=17.990(4), c=17.754(2) Å and β=101.07(1)°, space group P21/c with Z=4; 3b·CH2Cl2 solvate, a=11.496(5), b=20.872(9), c=15.056(6) Å and β=94.77(4)°, space group P21/n with Z=4. Both structures were solved by the heavy atom method and refined by the least-squares procedure to R=0.141 for 3906 reflections and R=0.102 for 4595 reflections for 3a and 3b respectively. The geometry around the Pd atom in each complex is essentially planar. However, the coordination behavior of the CH2SCH3 group in 3a and in 3b seems to be different. In 3a, the CH2SCH3 group is bonded to the Pd atom through the Pd–C σ-bond and the donation of the sulfur to the metal atom, forming a Pd–C–S three-membered ring [Pd–CH2=2.06(4), Pd–S=2.367(8), CH2–S=1.77(4) and S–CH3=1.78(4) Å]. On the other hand, the CH2SCH3 group in 3b is coordinated to the metal atom as a methylenemethylsulfonium ion, containing a C=S double bond[Pd–CH2=2.208(13), Pd–S=2.303(6), CH2–S=1.678(14) and S–CH3=1.86(4) Å].
An Analysis of the CF2 Emission Spectrum in a CF2Cl2 Plus Metastable He System
Authors: Ishiguro Takahiko , Hamada Yoshiaki , Tsuboi Masamichi
Published: July 2006

Ultraviolet chemiluminescence caused by a reaction of metastable He and CF2Cl2 was observed. Laserexcited single-vibronic-level fluorescence of the CF2 ？dical thus produced was also examined. The main feature in the 250–400 nm region was explained as the CF2 \ ildeA1B1-\ ildeX1A1 transition. The observed vibrational-level population of CF2(\ ildeA1B1) resulting from this reaction exhibits a maximum near v′2=5. This fact implies that the product has a FGF angle of about 104°, which is nearly equal to the FCF angle (105.4°) of the reactant (CF2Cl2) molecule, rather than to the equilibrium FCF angle (122°) of the CF2 (\ ildeA1B1) itself.
The Crystal and Molecular Structure of trans-2,2-Diphenyl-3,4-dichlorothietane
Authors: Kumakura Shigekazu
Published: July 2006

The crystal structure of the title compound has been determined by means of X-ray diffraction. The space group is P\bar1 with a=11.665(4), b=8.775(4), c=7.092(2) Å, α=95.73(3), β=84.36(3), γ=104.90(2)°, and Z=2. The structure was refined to R=0.048 for 1770 reflections collected on a four-circle diffractometer. The thietane ring is puckered with dihedral angles, C(2)SC(4)/C(2)C(3)C(4) and SC(2)C(3)/SC(4)C(3), of 150.1° and 149.9° respectively. The conformation of the C–Cl bonds with respect to the thietane skeleton is (3e4e), consistent with that in solution derived from the dipole moments. The average distance of the two C–Cl bonds is 1.781 Å. The C(2)–S, C(4)–S, and C(2)–C(3) bond distances are 1.872(4), 1.811(5), and 1.545(6) Å respectively; agreeing well with the corresponding bond distances observed in the cis isomer of the compound; however, the C(3)–C(4) of 1.506(6) Å is much shorter. The bisector of the bond angle formed by the ring substituents at each of the ring atoms is tilted out of the corresponding CCC or CCS planes within the thietane ring so as to increase the staggering of the neighboring substituents. The angle of tilt at Cβ is larger than those at the Cα’s. The intermolecular S···S contact of 4.080(5) Å is normal in view of the usual van der Waals radii.
The Solvent Extraction of Alkali Metal Picrates by Benzo-15-crown-5
Authors: Takeda Yasuyuki , Wada Yoshimasa , Fujiwara Shizuo
Published: July 2006

Benzo-15-crown-5 (B15C5) extracted alkali metal picrates (MA) into benzene by forming M(B15C5)A or M(B15C5)2A complexes and moreover, in the presence of tributyl phosphate (B), B15C5 extracted rubidium and caesium picrates by forming M(B15C5)BA complexes. The extractability sequences of the M(B15C5)A, M(B15C5)2A, and M(B15C5)BA complexes are Na+>K+>Rb+>Li+>Cs+,K+>Rb+>Cs+>, and Rb+>Cs+ respectively. The extraction equilibrium constants for these complexes have been determined at 25 °C, and the synergistic formation constants of the M(B15C5)2A and M(B15C5)BA complexes in the benzene solution have been calculated. The synergistic effects for the alkali metal ions for the B15C5 system were compared with those for the 15C5 system.